2023-2024 Conference Tips 3 – Climate Change, less usual edible plants

Carrots under shade cloth in summer.
Photo Pam Dawling

2023-2024 Conference Tips Part 3 – Climate Change, Less Usual Edible Plants

I reported earlier on good tips I got from the CFSA Conference and the VABF-SFOP Summit.  Here I’ll continue the theme.

At the VABF-SFOP Summit, I also attended workshops on Meeting the Climate Challenge with Mark Schonbeck, and Eating and Marketing the Whole Plant with Chris Smith. I’ll tell you more about those now, then move on to the Pasa Sustainable Agriculture Conference.

Meeting the Climate Challenge: Sharing Stories, Co-Creating Solutions with Mark Schonbeck

Mark’s slides and handout will be available soon on the VABF website. In our region we are experiencing hotter summer nights, which are hard on plants (and livestock, I’m sure). At 95F (35C) most crops close down completely or slow their growth. For every 1.8F (1C) in warming, 3-10% of the Organic Matter is lost (burned up) and nitrous oxide emissions may increase 18-28%. Daffodils are flowering up to 5 weeks earlier, fruit trees are budding out earlier, risking losing the fruit to freezing nights. In the spring we are getting later cold snaps below 10F (-12C) in March.

We are having a longer frost-free period, with more generations of bugs. Downy mildew of cucurbits is spreading further north than previously.

Our kale beds after heavy rain. Photo Wren Vile

In Virginia we are getting more intense and heavier rains, with more flooding. The erratic nature of the rains means we can experience flash floods, followed by droughts and wildfires. Heavy rainfall leads plants to grow shallower roots, which then die if a sudden drought follows.

Keeping living roots in the soil will increase climate resilience, as will other ways of building healthy soils, such as diversified rotations, and varied agricultural enterprises. Here’s Mark’s list of

6 Organic Principles of Soil Health:

  1. Keep the soil covered
  2. Maintain living roots
  3. Return organic residues to the soil
  4. Minimize soil disturbance
  5. Diversify crops
  6. Integrate livestock.
Teff cover crop.
Photo Wikipedia

Increasing the use of cover crops will help with 1, 2, 3 and 5. Teff can be considered as a summer cover crop in alleys between plastic mulched beds. Mixing with clover gives better soil coverage. I have not yet tried this myself. Oats/barley/peas/mustard sown in March will grow big by June, adding lots of biomass. Oats/radish/legume cover crop mix will winter-kill. Silage tarps and landscape fabrics can help hold the soil in place.

Installing terraces, berms and swales will help with water management. Installing drip irrigation will help manage droughts. Protected growing, in hoophouses or caterpillar tunnels, will help protect from many kinds of extreme weather. There are steps we can take to mitigate climate change, and more information is becoming available.

Eating and Marketing the Whole Plant with Chris Smith

Chris is the author of The Whole Okra, and part of his presentation was about the many uses of okra, beyond cooking the pods. Okra leaf chips are the latest thing he has tried. The leaves are used for soup in Nigeria. The flowers can be eaten or dried for tea. The oil from okra seeds is nutty, citrusy, a bit like olive oil, although the yield is small, at 9-20%. The oil presscake can be ground for defatted flour.

Book Edible Leaves of the Tropics by Franklin Martin, Ruth Ruberte and Laura S Meitzner

Chris showed us a remarkable book Edible Leaves of the Tropics, by Franklin Martin, Ruth Ruberte and Laura S Meitzner. Plants for a Future  has a database of 8000 plants, including edible plants.  The Book of Greens by Jenn Louis and Legume Species as Leafy Vegetables by Robert P Barrett (online) are also valuable resources on edible plants.

DIYseeds.org educational films on seed production

Go to https://www.diyseeds.org  then search for info on growing seeds.

Male squash flowers can sell at $1/flower for an 8-week season. Winter squash yields can increase if some of the early male flowers are removed! Wisteria, redbud and black locust flowers are edible. Kudzu offers many food options (eat it up!) Roots of dandelion, burdock, thistle, sassafras, daylily, dahlia, runner bean and chayote are all edible.

Soil Health, Climate Adaptation and Mitigation Planning, Rachel Schattman, Sara Keleman and Nic Cook

In February 2024, I participated in the Pasa Sustainable Agriculture Conference.  The first session I attended there was Soil Health, Climate Adaptation and Mitigation Planning, with speakers from the University of Maine Climate Science department. They reported that the NE has seen a 15% increase in Growing Degree Days since 1948, and the frost-free growing season in Maine has increased by 14 days since 1895. California has seen a 40-50 day increase in that period. In Maine the temperature changes are greater in winter than in summer. Since 2012, half of the US has shifted to the next warmer winter-hardiness zone. It is helpful to watch indicator species to determine when to plant particular crops. (See my post on Phenology). Warmer temperatures mean that the air holds more water (7% more for each C degree). This means slower storms, more storms heavier rainfall. They also experience droughts, and distinguish between agricultural drought, meteorological drought, and hydrologic drought – be sure which kind your conversations are about.

Young blueberry plant in snow. Photo Bridget Aleshire

Sea level rise is dramatic on the East coast because of past glaciation. The other main impacts they are seeing on agriculture include False Spring (fruit bud kill after a “warm snap”), winter soil erosion and rain ponding, and new pests, diseases and invasive species, warm season heat stress including crop quality deterioration, greater irrigation demands and needs for shade and ventilation (drought can decrease yields 30%), storm intensity including hail and high winds, longer power outages, soil compaction and nutrient runoff, increased rainfall leading to delayed planting and crop losses. These are all possibilities to prepare for. The silver lining is that there may be new crops we can grow, or longer seasons of familiar crops. NRCS, Extension and other resources are available. Climate-Smart Farming and Marketing is a program for farmers from Maine to South Carolina, offering financial support and technical help to farmers implementing climate-smart practices such as cover cropping, agroforestry, reduced tillage and prescribed grazing.

Prescribed grazing is the intentional use of ruminant animals (hoofed herbivores such as cows, sheep, and goats) on the landscape. Unlike conventional grazing, prescribed grazing utilizes a grazing plan that dictates the location and duration of graze periods. This plan is informed by the ecology of the grazing area.” (Community Environmental Council).

Garlic beds next to rowcovered broccoli beds, under a stormy sky.
Photo Wren Vile

We were helped through an 8-stage planning process:

  1. Risk Assessment (prioritizing which aspect of climate change to deal with first). Heavier rains, then high temperatures, wildfire and smoke, plant diseases.
  2. Vulnerability (looking at your system, climate, location, and seasonal time period). Consider both Exposure to the risk and your farm’s Adaptive Capacity.
  3. Option ID. Consider all of small, medium large and total transformation of your farming. Divide your options up into 4 quadrants on axes of cheap-expensive, difficult-easy; low Greenhouse Gas-high GHG, reducing risk-increasing risk; low impact-high impact, quick to install-takes a long time.
  4. Evaluate tradeoffs (financial, ecological, social). Rank your options and select one that meets as many of your priorities as possible.
  5. Try to meet several goals with one solution. Consider seeking advice or funding.
  6. Monitoring and assessment. How will you measure the improvements?
  7. Revising/tweaking. Reflect and assess. Consider success at each stage.
  8. Share what you learned. Don’t expect perfection, or that others will expect that from you.

Next followed a section on funding. Currently there is lots in Inflation Reduction Act coffers for efficiency increases, renewable energy, conservation practices. Try REAP (Rural Energy for America Program), USDA, NRCS, Rural Development Office for your state, SARE funding for experimentation and trials, state agriculture departments, advocacy organizations, regional non-profits, Chesapeake Bay Trust, Farmer Resource Network, county grants, Beginner Farmer grants, grants for historically under-served farmers, Ambrook Accounting software for American farms..

Take a buddy with you to the offices!

Farmer Resource Network

Book Review The Ecological Farm by Helen Atthowe

Front cover of The Ecological Farm

 The Ecological Farm: A Minimalist No-Till, No-Spray, Selective Weeding, Grow-Your-Own-Fertilizer System of Organic Agriculture, Helen Atthowe, Chelsea Green Publishing, 2023. 368 pages, $44.95.

 In this inspiring book, Helen Atthowe explains her 35 years of experience farming fruit and vegetables in Montana, California and Oregon. This book will appeal to all those (especially orchardists) who are fine-tuning their land management. I think beginners could find it over-whelming, unless they take it in rich small doses! This is definitely a book to dip into and come back to as needed. It provides a Big Picture of ecological farming, not a step-by-step How To.

Helen clearly pays exquisite attention to her farming, conducts research and share her knowledge with others. She operated an Organic orchard in California, together with her husband Carl Rosato, who very sadly died in a farm accident in 2019. Helen and Carl together pioneered ways to raise tree fruit with no pesticides at all. Helen has expertise in ecological weed, disease and pest management, minimal soil disturbance, and managing living mulches, providing soil fertility without manure-based compost, and cultivating habitat for beneficial species. There is lots to learn from this book.

The endorsements for The Ecological Farm are staggering: fifteen well-known ecological farmers (fourteen men and one woman, what’s with that?). Clearly, this work is held in high regard by many experts in the field. The love of farming goes beyond achieving high crop yields, embracing connection with the land and all its forms of life. Helen says “The process of creating farms and gardens opens my eyes to awe, attunes my ears to listening, and offers the gifts of curiosity, discovery and deep connection.”

The ecological approach in this book goes beyond organic, which in the wrong hands simply substitutes a different set of substances for the banned ones, and doesn’t look any deeper. Helen has measured the effects that her actions have had on her land and crops, and shares her results so that we too can grow nutrient-dense foods and leave the environment in a richer, more balanced state than we found it.

The book contains dozens of Helen’s own beautiful full-color photos of plants, pests, birds, fruit trees and vegetables in various combinations. There are prepared forms for monitoring problems and planning interventions. There is a Vegetable Crop Growing and Troubleshooting Guide, a section on Vegetable Crop Insect Pests and Interventions, one on vegetable crop diseases, and similar sections for tree fruit crops.

The first half of the book sets out ten empirical and practical Principles for Managing Ecological Relationships. As the name emphasizes, it’s about managing relationships, not managing crops for highest yields, regardless of what else happens. The connections that form healthy farming ecosystems require us to pay attention, and avoid outside inputs in favor of balancing what is happening on our own farm. There are some excellent charts of applying the ecological principles.

The Principles include creating above- and below-ground diversity; minimizing soil disturbance; maintaining growing roots year-round (living plants secrete 30-60% of the carbon they capture from the air during photosynthesis down into the soil); growing your own carbon; adding organic residues all season; focusing on carbon fertilizers; recycling rather than importing nutrients; fertilizing selectively; weeding selectively; and creating beneficial habitat as close to the crops as possible.

There are many ways to build soil organic matter without removing large quantities of inputs from someone else’s land (not sustainable or fair, as Helen remarks); many ways to build habitat for beneficial organisms; many actions that can steer plants, animals and fungi towards better balance, so that the soil microbial community will thrive and cycle nutrients continuously.

Helen tells that when she started farming, she behaved like a “nitrogen hoarder”, focused on maximizing the amount of nitrogen the soil had available, and topping it up with compost and cover crops if the soil held less than the requirement for the next crop. Her soil management went through a three-stage evolution: She started to view the abundance and diversity of active microbes as the important bit, and the nitrogen level as merely a sign of that activity. Next, she moved to consider the whole soil organic matter system, rather than the parts as separate features to measure. Thirdly, she researched soil carbon and realized that microbially-active carbon was essential fuel for the soil microbes, and deserved more attention.

Actual measurements showed that, contrary to careful calculations, her soil levels of nitrogen, phosphorus and potassium were becoming too high. Helen had been generously adding sheep manure and clover compost at 7-10 tons/acre (18-25 tons/ha). She changed to using mown clover as her main fertilizer, and learned to manage the carbon:nitrogen ratio, with the goal of achieving steady decomposition of organic residues and increased microbe populations and diversity. Simply adding more high-nitrogen material will not provide good crops! We need to build carbon in our soils, and optimize organic matter decomposition and nutrient cycling.

Helen discovered that the C:N ratio of mowed clover living mulch residue varied according to the time of year, being highest (least nitrogen, nodules not yet formed) in July and lowest (most nitrogen, clover flowering) in August and September. This affects nutrient availability and decomposition rate. Vegetable crops do best in Helen’s system if she tills once a year and regularly applies both high-C and low-C residues on the surface. The continuous organic surface residue supply is much better than an annual large dose. Timing when and how we apply organic residues influences their C:N ratio, and hence how we build up carbon in the soil.

Minimizing tillage is another way to build soil organic matter. Incorporated clover releases nitrate-nitrogen into the soil much more quickly than surface-applied cut clover. If your soil has an active and diverse microbial community, incorporating legume cover crops in spring can give a quick burst of nitrogen (for a few weeks), then a sustained regular release of more as it slowly decomposes. With no tillage there is a lag time. No-till does keep the fungal food webs unbroken, which has advantages. It is important to focus on the carbon fertilizers rather than fast-release nitrogen fertilizers. Since 2016, Helen has used only mowed living mulch as fertilizer for most crops, paying close attention to the timing of mowing. The vegetable plots also benefitted from the living mulch in the row middles growing over the bed after the food crop was finished.

I had to look up “row middles” to understand the methods better. With rows of fruit trees, row middles are the aisles between rows of trees. They can be planted in cover crops, which can be mowed and the cut material blown into the tree rows to act as mulch. The photos of vegetable production (other than her home garden) seem to show aisles wider than the beds, so that less than half of the land is in vegetables and more than half is in cover crops. This fits with the method of growing lots of cover crops as the main source of soil fertility. And with Helen’s method of always leaving half of the living mulch row middles unmowed to provide good habitat for beneficial insects. Over here on the East Coast, I am more used to intensive vegetable farms with narrow aisles between beds, perhaps because land is more expensive, perhaps because Bermuda grass is so invasive as to scare off anyone who might consider permanent paths. Jennie Love, a flower farmer in Philadelphia, uses Living Walkways. Hers are 21″ wide, mostly grass and weeds, and require mowing every single week. Helen’s are more focused on legumes, especially clovers.

To focus on a soil organic matter system driven by microbial activity, attention goes to C:N ratios, optimal decomposition speed and nutrient cycling of the cover crops, mulches and composts. As Helen admits, this can be overwhelming, so don’t change everything at once! As you gain experience growing your own fertilizers, you can cut back on imported fertilizers. Do provide a diversity of organic materials throughout the growing season. Having just one kind, all at once is, for the soil, like us eating a whole giant cheese pizza! Soil “indigestion” takes the form of an over-population of just a limited specific microbial community.

Decreasing nutrient inputs and increasing application of organic residues leads to an increase of mycorrhizal fungi. Including chipped woody compost increases the soil carbon. Adding cover crops increases not just the soil nitrogen but also the carbon as more microbial bodies are born, feed and die. Raw organic matter is to be avoided as it acts like an unmanageable surge that can burn plants (by releasing high levels of salts and toxic byproducts) and leach nutrients. In hot humid climates, it is best to aim for slow decomposition to balance the climate’s effect causing fast decomposition. Aim for ten weeks’ worth of nutrients, not more, and watch for foliar signals of nitrogen or phosphorus deficiency that last for more than 3 weeks – a sign that things are out of balance.

In early spring (if early harvest is a priority) you will need to provide easily available nutrients. The first couple of years after switching your focus to carbon, you may be frustrated by the slow rate of decomposition and the lower yields. It takes weeks longer for surface-applied plant matter to release its nutrients than it does for tilled-in plant matter. This requires patience, planning and also has financial implications. Wait 2-4 weeks after incorporating organic residues, or 4-6 weeks after spreading them on the surface, before planting. Animal manure is not essential for soil fertility. After all, animal manure is simply plant matter that has been partially digested. By applying the plant materials to the soil surface, the digestion is done by small soil animals. It’s not so different!

Letting living mulch grow tall in very wet or very hot weather will help dry or cool the soil, but don’t let the cover crop out-compete the food crops for water! Adding cut covers is also a way of adding to soil moisture. Helen is a fan of minimizing tillage, not of banning it.  Tillage decreases organic matter, microbial diversity and abundance, and disrupts the fungal chains. Strip tillage tills out narrow strips to plant into, from an existing sward of cover crops. Tillage incorporates organic residues, adds air, and stirs up a burst of biological activity, helps warm up spring soils, reduces weeds and breaks up compaction. These benefits can be put to use rather than scorned. “Practice tillage with intention” as Helen advises.

Likewise, compost can be useful when starting on poor land, or needing to address some other kind of imbalance. Don’t rule it out completely! There is plenty of information about making good compost here. Did you know the critical temperature for killing most weed seeds is 145˚F (63˚C)? This book also offers a recipe for a liquid fertilizer for “emergency use” on crops showing a nutrient deficiency.

Author Helen Atthowe.
Credit Cindy Haugen

I appreciate reading work by growers such as Helen, who have done the research and experimentation and responded to the science. An average of one page of footnotes per chapter backs up her claims. I’m not a fan of myths and “woo-woo” gardening. This book includes many useful charts and graphs, so you can see the facts. A four-year experiment started with a 50-year old grass, clover, alfalfa and weed pasture, was divided into two fertility treatments. The first was strip-tilled, with the mowed living mulch blown onto the 4′ (1.2 m) wide crop plots each spring. The second was similar, with the addition of 4″ (10 cm) of clover/grass/weed hay mulch in the late summer before the spring strip-tilling. The hay was cut from another field on the farm. Crop yields were economically sustainable in both plots all four years, and there were almost no insect or disease problems. Yields improved in the second and third years. Yields of some crops were higher with the hay addition – peppers and onions significantly; dry beans and cabbage slightly.

The information on choosing cover crops advises using mixes of crops with different C:N ratios, and including legumes whenever possible. This chapter includes recommendations on inoculants, cover crops for various soil types, and “biographies” of four perennials, 15 annuals and the biennial yellow sweet clover.

The book reminds (or informs) us that being able to stop using pest control sprays starts with building the soil, making it comfortable for soil microbes and creating habitat for natural enemies of the pests. The next step is growing healthy plants, by providing optimal conditions of light, temperature and water, and managing plant competition from weeds or over-thick sowing. After that, focus on the balance of nutrients in the soil, especially carbon.

Suppress pests, rather than focusing on killing them. Spraying insecticides, even organic ones, can disrupt balance and leave you inheriting the task of the creatures you killed. Killing all the prey starves the predators who were keeping the prey in check. Learn to intervene with the least possible impact. Tolerate non-threatening amounts of pest damage. Approach in this order: prevention, pest diagnosis, research, monitoring and ecological decision-making. Minimal-impact interventions include trapping and pest-specific microbial insecticides like Bt (which could require ten sprayings to achieve 98% damage-free Brussels sprouts); moderate-impact interventions include broader-spectrum microbials and materials like soap, horticultural oils and minerals; heaviest-impact interventions (those likely to injure non-targets) include using neem oil, pyrethrin, pyrethrum powder and spinosad.

Designing and maintaining a disease-suppressive ecosystem is the title of the section that focuses on preventing diseases. Crop rotations and diversity of crops and other plants are at the top of the list.

Plant competition is the description of the effect of weeds and over-thick planting. We are encouraged to focus on the weeds most likely to cause problems leaving those that can peacefully co-exist with the crop. Knowing and understanding weed ecology is important: when and where does this weed do best? How can you make your vegetable gardens less comfortable for the weed?

Perennial weeds that spread underground need good attention. Helen deals with quack grass, which takes about four years to become a serious invasion problem, when three passes with the tiller 7-10 days apart in spring are needed. I’ve lived with quack grass (couch grass), a cool-weather invasive. It’s a challenge, but I do think the warm-weather Bermuda grass (wire grass) is worse. Tilling also deals with that.

Crop rotations, especially of crops that grow in different seasons, underground crops that need soil disturbance to harvest them, and crops that rapidly cover the soil, are a big help. Helen recommends growing a full-season perennial cover crop on 25-50% of your garden beds or farm area in production each year to break annual weed cycles.

Some cover crops, including cereal rye, hairy vetch, red clover, sunflowers and mustards all exude allellopathic compounds that inhibit germination of nearby seeds (weeds and crops). Often incorporating the cover crop in the soil works better than chop-and-drop, as buried plants decompose without much air, giving a stronger effect. Also tilling reduces the immediate competition from weeds. Tillage can increase yields even if you believe no-till is best! It’s a trade-off. Tillage reduces soil health. Perhaps the sweet spot is minimal tillage, such as strip tillage. Landscape fabric (reused for ten years) offers another method of weed management.

Part Two of the book (approximately half of the pages) covers an ecological approach to crop management and troubleshooting. I didn’t take as many notes of that. After the introduction to some techniques like interplanting, succession planting, making your own microbially-amended seed growing mix, and using season extension tools, the book focuses on thirty popular crops, with tips on crop management, pests and problems.

A tidbit I learned with spinach is that fall-sown plants that reach the two-true-leaf stage before winter will resume growth in late winter. I also learned that the western striped cucumber beetle has a reddish thorax, making it look more like our striped pigweed flea beetle without such sturdy leg muscles.

The crop management sections include soil and fertility needs and special ecological preferences. The problems sections describe symptoms first, then causes, then resistant cultivars and other strategies for avoiding that problem in future. A valuable reference, and good winter browsing when reviewing the season past and preparing for the coming year. The index covers a substantial 18 pages, in three columns, promising to be comprehensive!

Helen Atthowe still acts as advisor to her previous farm, Woodleaf Farm in eastern Oregon, and is a farm consultant in the US and internationally. I notice that Helen is a speaker at the November 2023 Carolina Farm Stewardships Sustainable Farming Conference.

Helen Atthowe, November 2017.
Photo from Veganic World