Book Review Compost Science for Gardeners, by Robert Pavlis


Compost Science for Gardeners by Robert Pavlis

Compost Science for Gardeners, Simple Methods for Nutrient Rich Soil, Robert Pavlis,

New Society Publishers, January 2023. 224 pages, 6 x 0.52 x 9 inches, charts, diagrams and photos. $19.95.

Robert Pavlis has been a gardener for over 45 years, and is a very good science writer. I have previously reviewed Soil Science for Gardeners and Plant Science for Gardeners. This is a valuable, concise, accessible book for home gardeners, and also homesteaders, market gardeners, small-scale and large-scale crop farmers.

The book gives an introduction to the what and why of compost, and then covers the role of compost in the soil, the science of composting, compostable materials, managing the composting process, the options of piles, bins and tumblers, easy composting methods, vermicomposting, Bokashi composting, eco-enzyme composting, buying compost, compost tea, choosing a composting method, using compost and discarding compost myths. There are some almost cult-like groups with beliefs about how to make compost that are not science-based. The author has formed a Facebook group, Garden Fundamentals, you can join, to learn science-based information and help bust some myths yourself.

Garden Fundamentals logo

The introduction explains the importance of high organic matter in the soil, and the cycling of carbon and energy that can increase soil OM. Soil with more organic matter holds onto nutrients better, leaching less, keeping more nutrients in place for the crops. As gardeners we can help the process. We can leave extra plant material where it falls, spread tree leaves around our plants, and establish bug hotels. We can make compost from inedible and unaesthetic plant matter and use the mature compost to fertilize and build the soil, and feed the soil biology.

Nationally, 30% of garbage is yard waste and food scraps. At the landfill, these produce methane, a greenhouse gas with 25 times more global heating power than carbon dioxide. And then add on the pollution from the garbage trucks. It’s plain to see that making compost benefits everyone (except companies selling fertilizer).

There are quick and easy ways of returning garden waste to the soil (chop and drop), and there are labor-intensive ways that kill some weed seeds and diseased plants, and break down woody fibrous materials. You choose. When you do it right, there are no noxious smells. There are even methods you can use inside your house.

Screening a large pile of compost for the greenhouse beds. Photo Wren Vile

The Role of Compost

  • Mulch: keeps soil cooler, damper; may or may not reduce weeds.
  • Fertilizer: contains lots of plant nutrients including micronutrients, that are slowly and steadily released. Because compost has a high Cation Exchange Capacity (CEC, meaning it can hold lots of nutrients), nutrients stick to it, reducing the leaching rate.
  • Soil Builder: adds organic matter, improving aggregation in both sandy and clay soils, helping soil ingredients combine into larger soil particles, upgrading soil structure.
  • Water retainer: a 5% increase in organic material quadruples the soil’s ability to hold water.
  • Toxin remover: compost attracts and binds toxins, preventing plants absorbing them.
  • Acidity buffer: compost brings soil pH closer to neutral, from either side of the scale.
  • Microbe feeder and habitat: More microbes = healthier soil. Add compost, don’t add microbes! Provide the right conditions and they will multiply.
  • Reducer of landfills and greenhouse gas.

If you haven’t already read the author’s earlier book Soil Science for Gardeners, I recommend that. There is a brief description in this book, and charts and a diagram of the soil nitrogen cycle. Plants cannot use large pieces of organic matter, but need it to have it decomposed enough to release the ions. Ions from organic sources or bags of chemical fertilizer are identical. What is different is the ratios and mixtures of ions you are applying.

Tilling is controversial, because it destroys soil aggregates, and brings up weed seeds from lower in the soil profile. Tilling adds air to the upper level of soil, increasing the rate of decomposition of the organic matter. However, it has been found that the organic matter deeper in the soil increases after tilling, so that the total in the top 12” (30 cm) remains unchanged. This may be due to plants making deeper roots (roots are OM!). If you don’t need to dig it in, it is better for the soil and the planet to add materials to the surface.

Digging compost into our cold frames in preparation for fall planting.
Photo Wren Vile

What happens during the composting process? Understanding this helps you make informed decisions in selecting materials and managing the process. Larger life forms play a role in composting by mechanically reducing material to smaller pieces, making the foods accessible to microbes. These macroorganisms do not thrive in hot conditions – they leave when things heat up, and return later. It doesn’t work to second-guess what the compost pile needs. Adding earthworms doesn’t help. They’ll make their own way when conditions are right.

Composting happens when microbes decompose organic matter. Different microbes will self-select for the conditions you provide, just as macroorganisms do. They will multiply and thrive if temperatures and moisture suit them.

Plants are made of cells, and cells are made of molecules. Manure is plant matter that an animal has started to decompose. It’s still made of molecules, mostly unchanged as yet. After composting, all the large molecules have been changed into smaller, simpler molecules: amino acids, simple sugars, the stuff that microbes seek out for dinner. After dinner, and also after life, microbes release nutrients that plants can use. Compost happens!

Here is a clear explanation of the various stages of hot composting and the various kinds of microbes active during the different phases of the process. Worth buying the book for this alone! If you have a lot of seeding weeds, choose a hot composting method, but also chose better gardening techniques that control weeds!

At a garden scale, it will take at least 3 warm months to complete a hot-composting process. In colder climates, it will take 4-6 months or more. Cold compost piles can take 1-2 years. Commercial compost can be “made” in two weeks, but it needs another month to mature. “The first phase of bokashi is done in two weeks, but it is not really composting,” says the author.

We are encouraged to understand the C:N ratio of the materials we use, rather than use the simplistic (and confusing) Browns/Greens concept. Mostly we are feeding microbes, and their perfect food has a 24:1 C:N ratio. There is a helpful table of the C and N content of various compost materials you can use to calculate a recipe, using what you have available. The author offers an Accurate Calculation Method, an Easier Method, and an Even Easier Method.

Don’t worry about the pH. You don’t need to add lime. Home-made compost is usually in the 7.0-7.5 range initially, and drops a bit once in the garden.

A large proportion of the nutrients in finished compost are only released slowly (over maybe 5 years). If you run short of compost one year, don’t worry, your soil probably has enough from previous applications. When is a pile of compost ready to use? Try the Seedling Test. Put some compost mixed 50:50 with soil in a pot. Compare with a pot of just soil. Sow some quick-germinating seeds in each pot. As they emerge, compare the seedlings in each pot. If the plants grow equally well in both pots, your compost is fit for purpose. If the seeds in the compost/soil mix don’t emerge, or are stunted, allow the compost to age longer.

Robert Pavlis has three lists of compostable materials: Good, Bad and Controversial. He addresses antibiotics in animal manures, herbicides in animal fodder and yard trimmings; unnecessary worries about coffee grounds and various food scraps; eggshells, woody branches and used potting soil (OK but pointless); paper and its possible included toxins (not enough to worry about, in the author’s opinion, but not a particularly useful compost ingredient anyway).

The controversial ingredients include diseased plant material (know which disease, advises Pavlis); “compostable” plastics (they don’t break down using garden compost methods); human waste (too much sodium in urine, maybe transmissible diseases in feces); pet waste (maybe your own dog or cat, whose parasites and diseases you already risk, but not other people’s pets, unless you do a good hot composting method); toxic plants (diluted by other ingredients, digested by microbes, don’t worry); weeds (if you don’t let weeds seeds, you won’t have to worry about the compost; if they do seed, you’ll need hot composting the render them unviable; pernicious perennial weeds are best killed before composting); wood ash –  no point as it doesn’t compost, useful to add directly to acid soil.

Bad composting materials include “disposable” diapers (contain plastic and hydrogels); thorny plants; dryer lint, carpet fluff, vacuum cleaner bag contents, fabrics (these days these are largely synthetic fibers or cotton treated to be crease-resistant).

Compost-making is both art and science, and individual gardeners have their preferred twists on the basic method. Basic principles include

  • Location: indoors or outdoors? Indoors limits your options of method. Outdoors, you’ll need a water supply, proximity to the garden and other sources of materials (truck access?), a flat area with drainage and sunshine, and distance from neighbors. Check local laws.
  • Storage of ingredients: to use a hot method, you’ll need to store ingredients until you have a quantity and balance of inputs to build a pile. If you can’t do this, go for a cold system.
  • Air: turn the pile, or stir with an aerator, or make the pile with vented piping included, or layer the materials as you make the pile.
  • Water: add some every few inches as you build the pile. When you turn the pile, squeeze some of the material – it should be damp like a sponge, not sodden, not dry. Add more as needed. In wet climates, add a roof or a tarp over the top. If the pile gets too wet, turn it and fluff it up.

Get a compost thermometer, and once the pile reaches 145ºF (63ºC) – possibly as often as once a week – turn it to mix things up and start it reheating. Compost tumblers make turning easy. Three-bin systems give you somewhere to turn the pile into. A fork is the best tool for turning compost. One way to speed things along is to pre-shred your ingredients, perhaps by spreading them on a patch of grass and mowing them.

You do not need to add compost activators. These may be just microbes, which you should have plenty of. Or they may contain some fertilizer, in an expensive form. You don’t need to add phosphorus or potassium, but you might benefit from adding some nitrogen. Urine diluted 10:1 with water can provide that.

Once the pile no longer reheats, you have reached the curing stage, which takes about two months. Immature compost has a high C:N ratio, and is acidic. It could damage plants. If you are spreading your compost on the soil rather than incorporating it, you don’t need to cure it. This minimizes leaching. If you plan to dig it in just before planting, better to fully cure it first.

There is a troubleshooting chart of things that can go wrong and how to fix them. There are some photos and tables of pros and cons of each outdoor composting system. Resist any urge to turn your compost tumbler more than once a week, or you will disrupt the heating cycle and slow things down.

Pit and trench composting are methods involving gradually filling holes in the garden with compost materials and then covering with soil. This method works well for kitchen winter and spring, when there are fewer other ingredients. A keyhole bed with a central cylindrical cage for compost materials is a version of this idea.

There are electric “composters” which grind and dry kitchen scraps. They do not actually compost the food scraps, or even finely grind them. They use your money to produce dried food scraps, not fertilizer. And they use electricity doing it. When mixed with soil, the food rehydrates and grows mold.

Six worm bins.
Photo NCSU

Vermi-composters are bins holding worms, food scraps and other organic material, which together produce worm castings, which can be used as fertilizer. Vermicomposting is faster than traditional hot composting and can be done indoors, even in winter. The book contains enough detail for you to know whether this practice is one you want to try.

Microbes are the worms’ main food. Worms only digest 5%-10% of their food intake. The rest is excreted, along with a lot of microbes. Learn how much to feed, so that it has mostly gone by the next feeding. 1000 worms (1lb, 0.5 kg) will eat about 0.5lb (0.25 kg) each day. When food runs out, the worms will eat the bedding. Shredded newsprint, fall leaves, aged wood chips and more, make good bedding. There is a trouble-shooting chart.

The worm bin material (“vermicompost”) is a mix of worm castings, bedding material, uneaten food scraps, nutrients, worms, worm egg cocoons and microbes. While the worm bin is active, leachate liquid drops out from a drain hole in the bottom of the bin. This contains organic matter, nutrients and microbes. It can get smelly. It can be diluted 10:1 with water, to use on potted plants, or to water the garden.

Vermicompost will be ready to harvest 6-24 weeks after setup. Ideally, about 50% of the bin will be bedding and compost, and 50% castings. You can use the castings and compost mix in your garden right away. Worm castings have 10-20 times as much microbial activity as soil or most other forms of organic matter. They compost themselves once in the garden. To use for potting soil store it for two months, then mix 20% by volume in your potting mix.

The composition of vermicompost is a little higher in N than regular compost made from the same materials, and the potassium is the same, but the phosphorus is almost four times the level in the regular compost, which can be a problem if your soil is already high in P.

Next the mysteries of Bokashi fermentation (often called composting) are revealed. It’s an anaerobic process, similar to making silage, but usually done in small batches for small gardens. Most pathogens are killed. Waste organic matter is combined with sweetened “Bokashi bran” which contains fermentation microbes in a lidded bucket. Bokashi can be made indoors, and is a useful option in climates with cold winters. All kinds of food can be included with no worries about rodents.

Ignore the claims about “Effective Microbes,” because a study has found them unnecessary. Farmers often start Bokashi with naturally occurring microorganisms rather than buying the 80-microbe EM-1 product. One study found. no difference between using indigenous microorganisms, yeast or nothing at all.

A dark liquid leachate is drained out of the bottom and used as fertilizer, diluted 1:50 with water. It is low in nitrogen, but high in phosphorus, sodium and chloride. See the photos in the book for proof that it is not a good solo fertilizer.

The full bucket is left for a couple of weeks, and then the material is either added to a compost pile or to a large worm bin. It is not ready to be used for plants. You could save time and just feed the raw materials directly to the worms. The pH of Bokashi is around 4 (quite acidic), whereas the pH of compost is about 7.

The Eco-enzymes process, also known as Garbage Enzymes, is similar to making Bokashi or sauerkraut, and is popular in some households in Thailand and nearby countries. It reduces the amount of garbage going to the landfill. The system relies on the microbes already on the surface of the foodstuffs. None are added. Anaerobic conditions prevent pathogens from growing.

Enzymes are proteins created in living organisms. They carry out most of the chemical reactions that take place in the cells, including digesting organic matter. To start an eco-enzyme process, combine 3 parts of chopped organic matter, 1 part of sugar and 10 parts of water in a closed container. Open the lid once a week to let excess pressure escape. Wait three months at room temperature. Then separate the liquid from the solid ferment.

The liquid contains acids, alcohols, bacteria, yeast and protease, amylase and lipase enzymes, as well as plant nutrients.  It can be used to fertilize plants, or as a cleaning product with antifungal and antibacterial properties. The solid ferment is similar to Bokashi ferment, and needs composting to be useful to plants.

A commercial compost windrow turner.
Photo by Pam Dawling

Not everyone can make their own compost in large enough quantities. Some municipalities collect compost materials and make compost, which is then sold locally. Because a hot composting process is used, there will be no pathogens or weed seeds. There are no national US standards for compost, so read the small print.

Bits of food packaging, microplastics (less than 5mm in length) and nanoparticles (smaller) will be in municipal compost. A 2021 US EPA study found 300 pieces of microplastics per gram (8,400 per ounce) of food waste collected from grocery stores. Make your own compost if you can!

Chemical contamination is another concern. Pesticide residues will mostly (not entirely) decompose during composting. Leaves from city streets may have picked up oils and car exhaust compounds. Heavy metal contamination can come in with industrial wastes, or sewage sludge (biosolids), and unlike pesticides, will not degrade. Class A biosolids are tested for fecal coliform, salmonella, heavy metals and a few chemical contaminants. They can be sold as suitable for garden use, although not on Organic farms.

Some herbicides are digested by grazing animals, some degrade if composted, some bind to the soil. Some plant growth regulator herbicides, however, pass straight through livestock and kill the plants they land on. The list includes clopyralid, aminopyralid, aminocyclopyrachlor and picloram. Manure, compost, straw or commercial organic fertilizer can be contaminated. Organically produced materials should not contain these toxins.

Mushroom compost is pasteurized after the mushrooms are grown, and sold to vegetable growers. The material does not contain the right nutrients to grow a second round of mushrooms, but is useful for vegetables, with an NPK of 1-0.7-1, with a high calcium level.

Compost tea comes in two main kinds: anaerobic and aerobic. The anaerobic method is to put some organic matter in a container of water. Wait at least a few days, then draw off the liquid. Microbes will have decomposed some of the material and released some nutrients. Some people call this type of tea a “watery extract” to distinguish it from aerobic compost tea, which has air bubbled through it until done. To make “tea” you can use finished compost, weeds, comfrey, vermicompost, manure.

Compost tea does have some benefits in the garden, but not as many as some wishful thinkers believe. An increase in plant growth has been shown in studies in comparison with water. Not surprising! No study has shown better results from compost teas than other plant fertilizers with similar amounts of the same nutrients. It’s cheaper for you to make compost tea than buy fertilizer. But it may be better value for your time and money to use the organic matter you would have made into tea, in some other kind of compost.

Does compost tea build healthier soils? It is mostly water, which doesn’t build soil. The solid matter left behind might improve soil structure if added directly. The tea does not. Adding microbes via compost teas does not increase the number of microbes in the soil, except very short-term. Microbes will die and feed each other, go forth and multiply until the number of various types have rebalanced, back to the same numbers before your intervention. In a 5-year tree study, compost contained 50% more microbes than compost tea did. Skip the tea-making!

If compost teas are sprayed on foliage, some of the microbes may outcompete some existing microbes, including plant pathogens. Some plant diseases (powdery mildew in some cases) were helped by compost tea. Others (gray mold, downy mildew) seem unaffected. Washington State University has done extensive research. Composts vary, tea-making varies, weather varies. Compost tea is far from a cure-all, that much is clear.

Which composting system suits your conditions best? The trench method works for gardens with no space for bins or piles. Eco-enzyme and compost tea are small scale activities. Vermicomposting and Bokashi can be done indoors in winter. A chart compares traditional composting, vermicomposting and Bokashi Ferment, and another chart compares six traditional compost methods.

If your compost is high carbon, with lots of visible leafy or woody particles, spread it on the surface. If dug in, it would need to find plenty of nitrogen to continue decomposing the carbon. If your compost is still “hot”, and not fully mature, don’t dig it in, as it could hurt your plants.

Robert Pavlis tackles the issue of using too much compost, leading to problems with very high phosphorus levels in the soil, by recommending 1” (2.5 cm) of compost a year as a sustainable amount. Commercial compost may contain an NPK ratio of 1-1-1, whereas plants use 3-1-2. Homemade plant-based compost might have an NPK of 3-0.5-1.5. If you use compost to supply all the P the plants need, you will need to supply more N. This is safer than using compost as your main source of N, and building up too much P in the soil.

Excess phosphate gets locked up in the soil, and it could make it hard for your plants to absorb iron and manganese. If this happens you may see interveinal chlorosis. Some crops are good at integrating and removing phosphorus from the soil, so the situation can improve over time, if you minimize the P you are adding each year. If you see no excess phosphate problems, I advocate for not worrying too much! Expect to get some of the nitrogen you need from cover crops, and added fertilizer.

As well as your preferences and conditions, environmental concerns are important to consider. How much carbon is lost as CO2 or as methane? How much nitrogen is lost? If you didn’t compost, what would your alternative be? Would that produce more or less greenhouse gas? Sending organic matter to the landfill is the worst option. In general, the more aerobic your compost process is, the better for the environment. Bokashi and vermicomposting only take the material halfway to being composted. Remember that producing your own compost helps your garden soil and crops, and your wallet.

Robert Pavlis has a new book Microbe Science for Gardeners, coming soon.

Book Review: Grow Your Soil! by Diane Miessler

Book Review: Grow Your Soil! by Diane Miessler

Harness the Power of Microbes to Create Your Best Garden Ever

Storey Publishing, January 2020

  • Price: $16.95
  • Size: 6 x 9
  • Pages: 176
  • Format: Paperback ISBN: 9781635862072
  • Other formats: Ebook

Grow Your Soil! is an introduction to soil biology and gardening in eight chapters. It is written as if describing how to build a house (but starting with the roof!). Diane Miessler writes in plain English, with a light style, and her book has the endorsement of Elaine Ingham, who writes the foreword, saying that Diane’s humor and tongue-in-cheek joy make this book a joy to read. People were once told that using inorganic fertilizers and pesticides was the only way to grow enough food for a starving world. Elaine simply states “That was a flat-out lie.”

Diane’s encouragement to garden in partnership with the soil food web lists the many benefits of a healthy environment, healthy flavorful food, and the satisfaction of doing what you believe is right. She has a ten-point list of suggestions for creating healthy living soil using no-till systems, lots of mulches, home-grown fertilizers, and by encouraging biodiversity. The fundamentals of soil science are explained – soil is about 45% minerals (sand, silt and clay), 20-30% air, 20-30% water and 5-10% organic matter. A teaspoon of good soil contains more microbes than there are people in the US, more species than all the vertebrates on Earth, several yards of fungal hyphae, a few thousand protozoa and several dozen nematodes (mostly good ones). Soil is our planet’s third largest carbon sink (after the oceans and fossil fuels). Healthy soil is continually pulling carbon dioxide from the air and sequestering it in the organic matter and humus. We want to have as much sequestered carbon as possible, both to reduce the amount in the atmosphere and so that we can use it to grow food.

 Diane’s mulch recommendations are to generally aim for a mix of one-third green matter (which feeds bacteria) and two-thirds brown (which feeds fungi), but steering towards more green matter for annual vegetables, more brown for woody perennials, in line with the predominant life-form each type of crop does best with.

The cover crops section first describes the plants, then how and when to use them. I had a brief worry that people would go out and plant buckwheat or sweet potatoes in winter, until I read on! In fact, Diane does suggest you can sow buckwheat whenever you like, and it will be dormant until the right spring weather occurs. In our central Virginia climate this does not work. Buckwheat seed rots in cold wet soil. Buckwheat can germinate in a warm early spring spell and be struck down by a following frost before it has made much growth at all. As always, it pays to discuss ideas you haven’t tried before with nearby gardeners.

This book has a good basic description of the Soil Food Web, for new gardeners or anyone who is a bit mystified about what’s happening in the soil. And for those over 50 whose biology classes only included the two plant and animal “kingdoms”, here are explanations of the classes of bacteria, fungi and archaea, the main types of soil microbes. Archaea are neither bacteria nor eukaryotes (tiny organisms that have their DNA in a nucleus). Archaea are similar to eukaryotes in some ways, but have more resistance to extreme conditions. In the soil they work as decomposers.

Next up are the algae, protozoa and nematodes. The algae spectrum goes from one-celled photosynthesizing life-forms to giant kelp. In the soil they provide nutrients and increase plant resistance to diseases. Protozoa are one-celled animals, which release excess nutrients from their meals of bacteria and fungi, in a plant-available form. They help balance the numbers of bacteria in the soil. Nematodes are (mostly) microscopic roundworms that are mostly benign, from our perspective, and healthy populations keep the destructive nematodes in check. Arthropods (including insects, spiders, mites, ticks and scorpions) are shredders of organic matter in the soil (while eating smaller life-forms).

Bigger soil-dwellers include worms, slugs, snails, and small mammals. By the way, Diane explodes the myth that coffee grounds can control slugs, and claims to have videos to prove it untrue. And she tells us that fence lizards eat harlequin bugs. (I think she lives in California). Western fence lizards are centered in California, and according to the National Wildlife Federation, Eastern fence lizards are found between New York and northern Florida and as far west as Ohio and Arkansas. I want some!

The next section of the book explains Cation Exchange Capacity (CEC), a measure of how many positively charged ions (cations, nutrients like Mg, K, Ca, ammonium) can be held by the negatively charge soil particles. Diane likens this to the pantry. Soils with a low CEC can’t hold many cations, and the key to increasing the CEC is to increase the soil organic matter content. Clay soils may have a high CEC, but the nutrients may be held too tightly to be useful to plants. The solution to this problem is also to increase the soil organic matter content.

Diane offers several ways to increase the organic matter, and one of her favorites is biochar. Biochar in its original form is more or less sterile, not nutritious at all, but in the soil it can act like humus on steroids – it is very good at absorbing water, hosting microbes, reducing plant diseases and lasting a long time in the soil. I have been skeptical about some of the claims for biochar, and of the net gains in reducing global heating. Diane does not make any wild claims (she’s not selling the stuff). She is open about the fact that the mechanism for suppressing disease is not yet understood.

As I said, Diane is not selling biochar. In fact she describes how to make your own on a small scale with an “upside-down” outdoor fire (with all due safety precautions). Big pieces of wood are arranged on the ground in an open airy stack, and a small fire is lit on top with tinder and kindling. This means the fire produces little smoke (all smoke is air pollution). The fire is thoroughly doused with water once everything is glowing but not flaming. Those wanting to make biochar on a bigger scale are referred to a double-barrel biochar burner on YouTube.

Diane Miessler

The next section is on photosynthesis, minerals and soil testing. Diane describes the effects of too much, too little and just right amounts of the main soil nutrients first. A deficiency of phosphorus shows up as blue-purple colors on the older leaves. She doesn’t mention phosphorus surplus, although she does confirm that excess phosphorus added to the soil will usually be locked up and become inaccessible to plants. Potassium deficiency can cause yellow leaf edges. Next up are other macro-nutrients, such as Calcium, magnesium and sulfur. Calcium deficiency leads to stunted new growth, brown around the edges, perhaps with yellowing between the veins. Bulb and fruit formation can be damaged, as with blossom end rot of tomatoes, caused by insufficient calcium reaching the fruits. By contrast, a magnesium deficiency leads to older leaves becoming yellow between the veins and around the edges, perhaps with purple, reddish or brownish discoloration. Sulfur shortage can lead to “unthrifty” plants. Shortages of any of these can be remedied by the addition of more organic matter.

Micronutrient shortages can also be helped by organic matter, although in Virginia I have noticed that we do sometimes need to add boron on its own (in tiny amounts).

Diane describes how to test soil, understand the results, and remedy the situation. Try adding organic matter first, and only tinker with the specifics if the general remedy is not enough. For instance, if your soil biological activity is low, you may find that piling on organic matter doesn’t help. Use compost to add  some more life to the soil and get a better balance of diners to dinners. There is a helpful one-page “Order of Operations for Fixing Soil”: Correct the pH; correct the calcium level; correct any excesses (usually by adding gypsum); correct the macronutrient deficiencies and lastly correct the micronutrient and trace element deficiencies. Clear instructions like this are so valuable to newer gardeners!

There is a chapter on making compost and compost tea. She suggests thinking of compost as a sourdough starter, and mulch as the flour. Both are valuable, and they work well together. Making good compost is a valuable skill to learn. Try for the a good balance of high nitrogen materials and high carbon materials, with enough water. Turn the pile, assess its progress, add what it seems to need. Rinse and repeat. Diane recommends against spending money on fancy compost bins. “Compost needs love, not a container.” There is value in turning the pile and seeing how it’s doing. If it’s fully enclosed in a tumbler, you might miss the signs that it needs a specific kind of care. Here is encouragement to learn the art and science of compost making.

Worm bins are a great way to use kitchen scraps to produce worms and compost, especially in winter, as worm bins need to be in a non-freezing place to stay alive. I disagree with Diane about using the liquid leaching from the bottom of the bin as a “compost tea” See my review of The Worm Farmer’s Handbook by Rhonda Sherman. This liquid might not be good for your plants. To make compost tea, put some of the wormcastings in water and bubble air though it. Instructions are in Diane’s book a few pages later.

Another small industrious worker is the black soldier fly. The (harmless) maggots of these (harmless) flies will out-compete other (disease-carrying and/or biting) flies in eating up kitchen scraps in an odorless way. They are also a favorite food of poultry, and there are clever ways of setting up a bsf bin so that the pupal stage will “self-harvest” by walking up a ramp and dropping into a collecting box. See YouTube for all the details.

After explaining these various aspects of growing good soil, Diane pulls everything together into a chapter on Building a Garden That Feeds Itself. Here you can learn about sprinkler irrigation,  mulching, planting, and selecting good tools. The next chapter covers being a good neighbor, by having a good-looking, good-smelling, productive garden that gets frequent attention. Diane advocates for pulling weeds and dropping them on the bed, without worrying about weed seeds or plant diseases. I can see this would work best in a smaller garden where things don’t get out of control, and in drier climates with fewer diseases and less chance for weeds to re-root. There’s a panel about roses that I didn’t read. (Roses are a great trap crop for Japanese beetles; I’m not a flower grower!)  A big help to beginners is the glossary at the end, and the bibliography of books on soil life.

If you are a beginner organic gardener, or you’re looking for a book for someone in that category, this book has a clear user-friendly approach. It won’t scare off newbies with too much detail.

Book Review, The Bio-integrated Farm by Shawn Jadrnicek

Publisher: Chelsea Green. ISBN: 9781603585880

This book, by Shawn and Stephanie Jadrnicek, was hidden in my “to read” pile for too long! The title doesn’t make it clear enough that this is an authoritative text on all kinds of water management on the farm: integrating ponds, swales, ditches, water catchment, heat storage in water, irrigation, water for light reflection in winter, fish and shrimp-farming. Chickens and black soldier flies, compost-making and vegetable production in hoophouses and outdoors are all part of the bigger picture.

This book speaks from Shawn Jadrnicek’s experience at the Clemson University Student Organic Farm in South Carolina, and at his own homestead. The author tells us honestly when things he tried didn’t work out, and why. It is a permaculture book written for non-believers as well as the converted. It does not mystify with strange jargon. It does not make unsubstantiated claims about how things ought to be. Full disclosure: I suffer from having read too much permaculture writing that was obscure, convoluted, not backed with direct experience and written for people with a lot of time and only a small piece of land. This book is a breath of fresh air! The ideas have been tested on a farm scale, with a close eye on efficiency. It’s written for market farmers, homesteaders and serious gardeners, showing how to make best use of natural resources to help feed the world. Each technique has to have at least seven functions to qualify for inclusion in the author’s farming practices and the book.

You may not want to follow all of the author’s methods. I, for one, am not going to grow hydroponically. (I doubt that fully nutritious food can be grown without soil, with just the nutrients we know to feed in.) You may not want a hoophouse that is almost all pond. But you may be very happy to find a book that describes how to build a hoophouse on sloping land; very happy to learn how to grade your land to move rainwater away from where you don’t want it to sit, to where you do want it to improve growth of your pastures. You may be very happy to learn how to use a pond to grow minnows (tadpoles in the non-minnow season) to feed chickens. You may like the idea of filling your hoophouse with sweet potatoes or cowpeas in summer to act as a “smother crop,” dealing with weeds while keeping the soil alive. Perhaps you’d like to try freshwater prawn (large shrimp) farming? The regulations are easier than for fish-farming. Giant river prawns can weigh as much as a pound, they are easy to process and cook, and they sell at a good price.

Water management fills over half of the book, complemented by 30 pages on chickens, 33 on compost, 13 on fly farming, 28 on field layout and drainage, and 56 pages of case studies. Most of the vegetable production mentioned takes place in hoophouses (high tunnels). The book includes various ideas for heating the indoor crops, using hydronics (indirect heating with water in pipes warmed in outdoor ponds or compost piles), indoor ponds with solar pool covers, and compost piles leaning on the sidewall of the hoophouse. The information on rainwater harvesting includes checking your roofing material for toxicity (there is a special coating you can put on if necessary), how to avoid leaves clogging gutters (cleverly designed downspout filters), regulations about harvested rainwater, how to make gravity flow toilets and gravity drip irrigation systems that really work, and how to find the data and do the calculations. The level of detail in this book inspires confidence!

The chicken-farming system in this book uses a permanent coop and alley (mulched corridor) along with temporary pens made with electric netting. This makes better use of resources than free-ranging, unless you have only mature trees and grass. The birds get 30% of their dietary needs from the landscape, if rotated every 6-12 days onto perennial clover and grass pasture that has regrown to 4-8″ in height. This system ensures the chickens can always reach shade, and you can reseed bare spots in the resting pens with rye, wheat, millet, sunflowers and buckwheat, and reduce their feed costs by 30%. I liked the careful thinking and observation behind this scheme.

And then we come to the black soldier flies. The mesh flooring of the chicken pen lets the manure fall through into a fly digester below. The fly larvae digest the manure and grow, later becoming chicken food themselves. I wasn’t initially attracted to the idea of deliberately breeding flies, but the system has a lot going for it. Black soldier flies (Hermetia illucens) are not a pest. In fact they out-compete houseflies and thus reduce their numbers 95%! The adult soldier flies live only 5-15 days – they have no functioning mouthparts, and they don’t vector diseases. They are native in zone 7 and warmer, especially in the Southeast, so consult your Extension Service to find out if you’ll need to mail order them or just set out a nice digester once it’s warm enough. This sounds better than worm-bin farming! The flies tolerate a wider range of conditions and consume waste faster than earthworms. The large segmented larvae will “self-harvest” into buckets, if you have a well-designed digester. Two commercial models are available, the larger ProtaPod (4 ft diameter) and the smaller BioPod. They have internal ramps that the pre-pupae will climb, and a curled rim that prevents escape. The creatures launch themselves down a tube into a lidded bucket. All the details are in the book! Add fresh waste daily, and empty the bucket at least weekly (to prevent adult flies hatching out and setting up residence where you don’t want them).

The section on compost-making includes how to extract heat from your compost pile to warm your hoophouse, and how not to extract so much heat that the compost stops working. My beef with some other books about methods of heating greenhouses is that they fail to address the unintended side-effects, such as having very humid air go into your living space, or having little space left to grow plants because the greenhouse is full of heat-storing devices. Make good compost, and warm your hoophouse a bit.

The section on field application of these ideas is not about growing vegetables, but about field layout and drainage. It includes useful calculations on using drip irrigation. It also discusses keyline plowing, which had previously been just a bit of permaculture theory to me. Shawn says, “keyline pattern cultivating intrigued me for years, but I first had to implement the technique before becoming a convert.” There is no need to buy the special equipment some advocates suggest, if you have a box scraper with ripping tines. Keyline plowing (ripping 4″ deep in lines through pasture or grassways to direct water from a valley to a bit of a ridge) helps build soil and increase grass growth. Reading Shawn’s results, I now understand why others said it was a good idea.

I recommend this book to any small-scale farmers who are interested in learning efficient techniques to increase productivity while reducing use of resources.

Stephanie and Shawn Jadrnicek
Photo Chelsea Green

Book Review: High-Yield Vegetable Gardening by McCrate and Halm


Book Review: High-Yield Vegetable Gardening: Grow More of What You Want in the Space You Have by Colin McCrate and Brad Halm, Storey Publishing, December 2015

This book is intended for home gardeners who value efficiency and productivity. The authors, founders of the Seattle Urban Farm Company, explain techniques used by biointensive farmers and how to adapt these techniques for any size of garden. This professional help will assist gardeners to extend the season, increase yields, maintain healthy soils and deal with pests and other problems. This is not a beginner book telling you how to grow carrots (or any other crop). It will give you the information to choose the variety of carrot best suited to your goals, figure out how much land to put into carrots for the harvest you want, when to plant them, how to get maximum yields and how to have a continuous supply. It is not a book on marketing either. I want to set that out clearly, so no-one buys the book wanting something that it’s not. It’s a very good book if you want to “up your game” and get full potential from the land you have and the time you have available to spend working it.

This 7″ x 9″ spiral bound lay-flat book has 320 pages, including the index and resources section. The cover price is $18.95. It is illustrated with black and white drawings rather than photos, and has green spot color for headings and special sections. This gives an old-fashioned air to the book, until you come upon a drawing of a smart phone. There is nothing old-fashioned about the planning charts and spreadsheets.

After a poor start, on page 222 the gender ratio of the gardeners pictured starts to even up, and ends up close to the national average of 30% of farmers being female.

The book opens with three examples of high-yield gardens: A typical city lot of 5000 sq ft (including the space occupied by the house); a quarter-acre in the suburbs; and a rural one-acre plot. The authors discuss how to make a garden map and determine which factors influence how you use the site (shade for instance), and what your priorities are. They advocate for standard size raised beds in order to simplify planning and to reuse materials like row cover, netting or drip tape.

There are tables of crop spacing and scheduling for 60 annual vegetables and herbs, about 20 perennial vegetables and fruits and 20 perennial herbs. There is a worksheet to help you calculate how much of each crop to aim for, based on the average serving size, depending on your tastes, whether that’s non-stop arugula, tomatoes for canning or a large amount of carrots for a farmer wedding. Some of the charts can be downloaded from the Seattle Urban Farm Company’s website. There is a table of yields and one of planting dates, working from your own frost dates. There is a Planting Calendar Worksheet blank you can copy and use for each crop you plan to grow.

There are clear instructions on designing a crop rotation, including a chart of crop height, life span and fertility needs. They discuss practical limitations that might lead you towards either two rotations within your garden, or a separate rotation for the greenhouse. They urge you to keep good clear records. (Oh so important! Who has time to make the same mistake twice in farming?).

There is a Seed Order Worksheet, and a clear description of the word “hybrid” which has sometimes become a bad word among some gardeners who misunderstand the plant breeding work of the past century or so, and how it has brought us high-yielding, disease-resistant varieties, which are a boon to gardeners wanting high yields. Sure, you can’t save your own seed from hybrids and have it grow true, but who realistically grows all their own seed? So many crops cross with each other; sometimes seed-saving conflicts with getting food from that planting; seed-growing and selecting is a skilled job. Seed companies can do that work for us. I do grow a few seed crops, so I know what is involved. But I also grow many hybrids, and am grateful for them.

In a couple of places the drawing isn’t as good as a photo would be. The Jericho and Winter Density lettuces don’t look so different, and you couldn’t tell the size difference. The high tunnel (hoophouse) inflation blower tubing drawing on p 263 looks very strange to me, like maybe the artist has never seen a real one, and worked from a description.

There is a chart of seed longevity, a subject not always covered in gardening books. There is an excellent chapter on soil tests and interpreting them, which is very down-to-earth. (“We determined this to be about 75 and 50 pounds per 1000 sq ft.”) Nice and user-friendly, it won’t blind you with science. There is another good chapter on irrigation systems, a subject often ignored in backyard gardening books. “Because we strongly believe that hand watering a large, diversified garden site is an inefficient use of time and resources, we won’t even include it as a viable option for garden irrigation.” “Spending valuable hours trailing a hose through the garden is, at best, a poor use of your time.” Absolutely!

Setting up spaces to start seedlings and keeping them well-lit and watered is clearly explained. So is the subject of small greenhouses. The drawing includes the 1970’s craze of lining the back wall with black barrels of water, although the authors do point out that such devices can help, but will not be enough to warm the air to seed germination temperatures. In my opinion, the space given over to big barrels of water would be better given to more plants and the need for heat addressed in other ways!

There is a chapter on starting seedlings and planning for that on a large scale. It includes tips not found everywhere, such as when to sow rootstock and scion varieties for grafting tomatoes, starting cuttings, growing microgreens and hand pollinating. Planting depth is covered, including laying tall tomato plants in a small trench and planting brassicas up to the lowest leaves, rather than the same height as in the seed flat. There are recipes for mixing your own organic fertilizers, and which plants will respond most to extra nutrients. There are tables of organic management strategies for pests and diseases.

Compost-making is discussed, along with a table of Carbon:Nitrogen ratios of various compost ingredients. There is a table of cold-hardy salad crops and information about building low tunnels, caterpillar tunnels and basic types of small hoophouses for cold-weather growing. If you are planning a big hoophouse, I’d recommend getting more information than in this book. There is a chapter on harvesting, washing and storage.

As you’ve probably gathered by now, this is a book full of valuable gardening charts. If you are a grower who doesn’t want to work with spreadsheets, you can easily print off the Seattle Urban Farm Company’s worksheets and use those. Or take the spreadsheets and run. Either way, this is a valuable book for serious backyard growers.

March Events

I have two events in March, where I am making presentations. The first is an online conference (no travel costs!)


CSA Expert Exchange:
An Online Conference
Presented in partnership with Small Farm Central
March 6 – Want to Start a CSA?
Beginning Farmers Session
7:00pm-9:30pm EST
March 7 – CSA Expert Exchange Main Event
11:00am-3:30pm EST

Register for one or both days. Sessions will be recorded.
I am speaking on Crop Planning on Friday at 1.40pm.
Then on Sunday March 16, is the rescheduled day at Lynchburg College (postponed from February 15 because of all the snow). I am speaking on Feeding the Soil.
Ira, Cindy and Pam working on our presentations
Ira, Cindy and Pam working on our presentations. Photo Betsy Trice