Everything You Want to Know About Garlic: Garlic Almanac and Phenotypic Plasticity

Silverwhite Silverskin garlic
Photo Southern Exposure Seed Exchange

Everything You Want to Know About Garlic:

Garlic Almanac and Phenotypic Plasticity

(How garlic adapts to its locality)

It’s garlic harvest season for many of us and I notice many growers are searching my site for information. Here are quick links.

Garlic signs of maturity from October 2020

Everything You Need to Know About Garlic includes all the links listed below here.

Much about garlic is to be found in my Alliums for the Month Series:

Garlic harvest.
Photo Twin Oaks Community
Other posts about garlic, starting with harvest:
Pulling garlic scapes.
Photo Wren Vile

Phenotypic Plasticity

Phenotypic plasticity of garlic refers to the changes to a garlic variety grown in a particular location. Genetically identical garlics can grow differently in different environments. Garlic reproduces asexually, the new cloves are all clones of the mother plant, with no new genetic material introduced. And yet, over time, garlic saved and regrown each year in a certain locality will adapt itself to that location, due to the particular soil type, water availability, local temperatures, latitude, altitude and cultural practices. For example, studies have shown that varieties grown in drought-prone areas can, over years, develop more drought-tolerance. Commercial cultivars can have the highest bulb yield under well-watered conditions, but drought will show up the adapted strains in a comparison trial.

Garlic Plants
Photo credit Kathryn Simmons

We have been growing our own strain of hardneck garlic for over 30 years, and it does really well here. Originally the seed stock was a bag of garlic from the wholesale vegetable market. This is the very thing we are told not to do, as it may introduce pests and diseases. Indeed, it may, but our original folly is now deep in the past, and we have fortunately seen no problem.

I was reminded about phenotypic plasticity, when a friend and neighboring grower reported that the seed garlic we had passed on to her was doing well and was mature a couple of weeks before the variety she normally grows.

From the 2004 work of Gayle Volk et al, Garlic Seed Foundation analyzing 211 garlic accessions, we have learned that there are many fewer genetically distinct varieties of garlic than there are named varieties. Of the 211 accessions in that trial, only 43 had unique genotypes. But garlic shows high biodiversity and ability to adapt to its environment. The same garlic genotypes in different environmental conditions can show different phenotypes. This demonstrates the high phenotypic plasticity of garlic, probably linked to its complicated genetics, which somehow compensate for lack of sexual reproduction.

Work done in 2009 by Gayle Volk and David Stern, Phenotypic Characteristics of Ten Garlic Cultivars Grown at Different North American Locations  addressed the observation that garlic varieties grown under diverse conditions have highly plastic environmental responses, particularly in skin color and yield. This is a very readable paper for non-academic readers. Ten garlic varieties were grown at twelve locations in the United States and Canada for two consecutive years to identify phenotypic traits of garlic that respond to environmental conditions. The purpose of the study was to determine which phenotypic traits are stable and which vary with location.

Inchelium Red softneck garlic – note the small cloves in the center.
Photo Southern Exposure Seed Exchange
  • Clove number, weight and arrangement, clove skin coloration, clove skin tightness and topset number, size and color stay true to variety independent of location.
  •  Mostly, varieties classified as hardneck types produced scapes and those classified as softnecks did not, but there were some exceptions.
  • Bulb size, bulb wrapper color and bulb elemental composition (flavor) are related to location, (the influence of the local environment, such as the weather in that production year and the soil mineral content), rather than variety. The intensity of the skin patterns is highly dependent on the location. Some general trends were noted, but no clear correlation was found. (Read the study for the details).
  • For good size, predictably colored and flavored garlic, buy seed garlic grown locally that yields well. When garlic is grown in similar conditions to those in which it was produced, yields can remain consistent or improve.

    Our softneck garlic in May.
    Photo Pam Dawling
  • Varieties that grow well thousands of miles away are not a guarantee of a good result in your garlic patch. They may not match the bulb size, shape, color and flavor listed in the catalogs.
  • When grown under the same environmental conditions, the leaf number before bolting, flowering date, the final stem length, the flower/topset ratio, and pollen viability vary from one variety to another.
  • Studies that compared bulb firmness, pH, soluble solids, moisture content and sugar content with appearance determined that many of these traits are independent of skin color across 14 garlic varieties.
  • Bulb size was highly dependent on growth location with northern sites producing larger bulbs overall than southern sites for at least half of the trial varieties. Regional differences between varieties with respect to bulb size were noted, but because the project had a limited number of sites, specific variety recommendations for different regions were not provided.
  • Bulb size and weight were positively correlated with soil potassium levels.
  • Bulb sulfur and manganese content (flavor) were correlated with soil sulfur and manganese levels.

    The famous Music garlic, a hardneck type – see the stem.
    Photo Southern Exposure Seed Exchange
  • The demand for high-quality fresh garlic is increasing as restaurants and consumers seek out local vegetables. Consumers are attracted to colorful, unique garlic varieties for different culinary uses. As variety name recognition in garlic increases, understanding which traits define particular varieties and which traits vary within cultivars, depending on environmental conditions, will be valuable for successful marketing of new garlic types.

Garlic harvest finished, fall crop planning, tomato bug heads-up

Hanging garlic in vertical netting. Credit Marilyn Rayne Squier
Hanging garlic in vertical netting.
Credit Marilyn Rayne Squier

Today we finished harvesting our garlic. It’s a good feeling to have it all safely hanging to cure in the barn. Our climate is humid so we use lots of box fans to help the drying process. We started harvesting our hardneck garlic about ten days ago, and worked on that (among other tasks) for 4 or 5 days. We were short of workers, so progress slowed, and the softneck garlic took us parts of 5 days too, although there is much less of it. We grew 2880 feet of hardneck and 1080 feet of softneck.. This year’s crop looks good, both in size and condition. In about three weeks, when the necks are dry, we’ll start trimming, sorting and storing.

In our enthusiasm, we decided to grow more softneck next year, 1520 feet, and a little more hardneck, 3200 feet. The latter is just because the crop rotation brings the garlic to the central garden next year, where the rows are 200 feet long, compared to 180 feet in our west garden.

This leads directly into my next topic: fall crop planning. We are past the peak of planting things now. In the row crop areas we have the summer-planted potatoes, three more sweet corn sowings, and several more rows of beans, squash and cucumbers to go. The area in permanent raised beds will still see quite a lot of changes, and yesterday afternoon, while it was 97F outside, several of us sat down indoors to plan the raised bed crops until the end of 2015.

In early spring, we plan where to put the crops beforel August 4th, then in mid-June we plan the rest of the year. Usually we review the June-August 4th plans too, in case we want to change those for a better idea. In preparation for the group planning session, I toured the raised bed area and updated the map to reflect reality. For instance, our first bean sowings were a failure (it was just too cold!), so I whited out all reference to those. This makes crop rotation easier, as we don’t worry about crops we didn’t actually grow! I also prepared a chart of crops we might grow, along with quantities and start and finish dates. I divided the list by crop family (rotation, rotation, rotation!). And I updated our quirky Colored Spots Plan (here’s a version from two years ago)

Twin Oaks Garden Colored Spots Plan for crop planning
Twin Oaks Garden Colored Spots Plan for crop planning

It’s a map of our raised beds, with a colored dot for each crop grown, and a vertical line for each Winter Solstice. It’s a visually easy way to check if any given bed has had, say, brassicas in the past few years. A lot of information in a small space.

We started with the carrot family, as we usually grow up to 10 beds of carrots in our 60 beds in any given year. This year our first three beds did very well, so then we skipped a couple of plantings. We have one new bed of carrots, sown in late May. We decided to skip the next two Carrots are only sown here in June and July if we really must – hot weather carrots just don’t taste that sweet. We agreed to do our usual big planting of fall carrots on August 4th, in the row crop plot where we’ve just dug the garlic from. Hopefully we can grow a round of buckwheat between now and then. We were persuaded by a carrot enthusiast to grow a bed of over-wintered carrots, which we haven’t done for a couple of years. it’s a bit risky, they could all freeze to death. But if they don’t die, they are so delicious!

Ruby chard. Photo Kathryn Simmons
Ruby chard.
Photo Kathryn Simmons

Next we moved on to the brassicas. Nothing new here. We debated the pros and cons of turnips, and the pros won, so we’ll do two beds of turnips. We raised the question of kohlrabi – no-one keen. Beets and spinach next – we all love those. This group challenges our rotation, because we grow so much winter spinach, and spring and fall beets, and a bed of Swiss chard, all to be taken into account.

Alliums next. As I said, we decided on more softneck garlic. On to legumes. No cowpeas this year. No late successions of edamame. As usual, we’ll grow our last succession of green beans in our raised beds, where access is easiest, soil drains quickest, and we can keep an eye out for problems as the weather gets colder, and perhaps windier. We also plant our last successions of slicing cucumbers and summer squash and zucchini in the raised beds too, for the same reasons. It also lets us get the big row crop areas put into cover crops in a timely way.

A bed of young transplanted lettuce. Photo Wren Vile
A bed of young transplanted lettuce.
Photo Wren Vile

The planning task ends with finding homes for our last three beds of outdoor lettuce for the year. We plan these last because lettuce is such a quick turnaround crop, and only needs short-term openings of space between other crops. We transplant 120 lettuce roughly each week, fitting three plantings into each 90 ft long bed. After that we transplant into our greenhouse (until spring when we need the space and the compost they’re growing in, for our spring seedlings).

Lastly I want to mention a post I saw on Growing Small Farms by Debbie Roos in Chatham County, North Carolina. It’s about the tomato bug, a pest newly discovered there. It can do a lot of damage, so I, for one, will be keeping my eyes open for any sign of it arriving here in central Virginia. Click the link for lots of good photos and information about this pest. This website is a great source of information, and includes Farmer Resources, Web Resources, Crop Production and Pest Management.

Snipping, Sorting and Storing Garlic

Clipped garlic bulbs ready for sorting and storing. Credit Wren Vile
Clipped garlic bulbs ready for sorting and storing.
Credit Wren Vile

Here’s what we’re doing these hot, rainy afternoons (and a couple of rainy mornings) – taking our cured garlic out of the netting lining the barn walls, and preparing it for storage. It’s been curing (drying down) for about four weeks. In the process we are selecting which bulbs to keep to replant his fall.  Calvin figured we’ve grown enough garlic for each person to eat one whole bulb a week. i thought that was a lot, so I recalculated in the cool of the office. To my surprise the answer is closer to two whole bulbs each per week!

We have checklists for the people trimming garlic, so i thought I’d share those with you, so you can be a fly on our barn wall, or in case you grow garlic too,and wonder how other growers deal with the bounty.

A pleasant sit-down, social task. Credit Southern Exposure Seed Exchange
A pleasant sit-down, social task.
Credit Southern Exposure Seed Exchange

Setting up

  • Handle the bulbs gently so as not to bruise them. We need long storage, which means no damage.
  • Test for dryness by rolling the garlic neck between finger and thumb. If many bulbs are slippery, slidey, or damp in any way, cancel the shift, try again in a few days.
  • If 90% seem dry enough, proceed, working in the direction they were hung up.
  • Gently remove plants from the netting into a bucket. Do not cut plants off the netting leaving the foliage to drop down the back into Recycling on the floor below.
  • Set up a comfortable place to work, with a bucket of garlic, a compost bucket, a pair of scissors, a ruler and easy access to a green net bag and a red net bag.
  • Some people like to mark off 2”and 2 ½” on the arm of the chair, a nearby wood structure, or their knee. This saves handling the ruler repeatedly.
  • Some people like to move the box fans for more or less fan action while working. Those that do this need to remember to reset the fans to blow on the garlic when they leave.

Snipping and sorting

  • Cut the roots off the garlic into a compost bucket. Cut as close as possible in one or two snips.
  • Cut the tops off the garlic, leaving a ¼ – ½” stub. Cutting too close reduces the storage life.
  • Do not remove any skin. We want long storage not pretty-pretty.
  • Decide if the bulb is dry. Feel the cut neck. The remains of the stem may have a Styrofoam texture. Should not be damp.
  • If damp at all, put the trimmed bulb on a rack to dry further.
  • If more than 10% are damp, cancel the shift or selectively pull dry bulbs from the netting.
  • If not damp, decide if it’s storeable.
  • If damaged, sprung apart or mushy anywhere, put it on the Use First rack.
  • If storeable, decide if it’s seed size and quality. If it could be between 2 and 2 ½”, measure it. If smaller or larger, put in a red bag. It’s for eating.
  • If between 2 and 2 ½” and in good shape (not obviously more than 10 cloves), put it in a green net bag. Green for Growing
  • When a bag if full enough (we’re not all Amazons), tie the neck closed and lay the bag down on the floor away from the windows, which let rain in.
  • At the end of the shift, return all scissors and rulers to the jar, take all compost material out, consider doing a Compost Run. Lay down any bags that are more than 1/3 full, as the weight of garlic in a vertical bag can damage the bulbs at the bottom. Leave no garlic in buckets. If necessary, gently set garlic on the floor boards, rather than leave it in a sweaty plastic bucket. Make sure no garlic will get rained on if rain blows in the window. Reset fans as needed. Unplug any no longer needed. Remove all hats, water bottles, spare clothing.
  • Periodically weigh the tied off green bags, make neck tags from masking tape, saying “Hardneck Garlic” and the weight. Use the bathroom scales. Weigh a person with and without a bag of garlic.
  • When we have enough seed garlic, stop using green bags, stop measuring. Simply snip, sort and bag. We need 140 pounds of hardneck seed (2013)
  • When all the hardneck garlic is dealt with, and not a moment before, record in the log book all the weights of the bags of garlic as you take them downstairs.

Storing

  • Take the green bags to the Garden Shed. Lay them on the top central shelf.
  • Take the red bags to the basement and lay them on the shelves in the cage there. Use one side of the cage only, unless you need more space.
  • Weigh the Use First hardneck garlic, record the amount in the log, take the Use First garlic to the kitchen. It does not need to be refrigerated now. 55-70°F is good.

More Snipping and sorting

  • When all the hardneck garlic is finished, and removed from the barn, start on the soft neck garlic, if it is dry enough.
  • Do the same as with the hardneck garlic. If possible use purple (eating) and orange (seed) bags, rather than green and red.
  • We need 40 lbs seed. Once we have that, stop measuring.
  • When all is done, weigh, label, record and store the garlic; clean up the mess, return the lawn chairs.
  • Ah, another successful garlic harvest!

Storing through the winter

  • When temperatures seem likely to drop to below 55°F in the basement, clear the top left shelves in the walk-in and move the eating garlic there. The low shelves near the compressor do not work well. Use the high and dry shelves. 32-39°F is also a good temperature range. Avoid 40-55°F, or the cloves will start to sprout.
Polish White - our  softneck garlic variety. Credit Southern Exposure Seed Exchange
Polish White – our softneck garlic variety.
Credit Southern Exposure Seed Exchange

Harvesting Garlic

The crew harvesting garlic.  Credit Marilyn Rayne Squier
The crew harvesting garlic.
Credit Marilyn Rayne Squier

We’ve harvested about half our hardneck garlic in the past three days, a job that we always enjoy and find satisfying. I was surprised at how early the garlic was ready, given the late spring. Usually harvest is about three weeks after the first scapes are ready to pull, and we started pulling those on 5/10, so I should have been more ready. I know garlic maturity is day-length dependent, but temperature is also a factor. I just looked back at my post 6/6/12 Garlic harvest. Ha! I see I was surprised at the earliness of the harvest date last year too. Time to learn from that and not be surprised next year! Anyway, can’t argue with plants, so here we are, digging them up!

I checked for maturity on Tuesday, not expecting them to be ready. I look for two things:

  • The sixth leaf down is starting to brown on 50% of the crop. 
  • There are air spaces between the round stem and the cloves, visible when bulbs are cut horizontally.

Here’s our system:

  • If the soil is very dry, water the night before – Very hard soil can damage the bulbs
  • Plan 15 mins per bucket to dig garlic and 15 mins per bucket to hang it up. It’s important not to get left with garlic still in buckets at the end of the shift.
  • Carefully dig the garlic. Treat the bulbs like fragile, sun-sensitive eggs. Bruised bulbs won’t store well
  • Loosen them with digging forks, without stabbing them. Pulling on unloosened garlic damages necks, they won’t store well
  • Don’t bang, throw or drop the bulbs
  • If they have a lot of soil on the roots, use curled fingers to “brush” soil out
  • Try not to rub or pick at the skin. Bulbs need several layers of intact skin to store well.
  • Don’t wash the bulbs, no matter how dirty. They need to dry, not get wetter. Dirt will dry and drop off
  • Put the bulbs gently into buckets to shade the bulbs. Air above 90F can cook the bulbs, sun can scorch them
  • Take the buckets to the Allium Emporium and hang up the garlic.

The “Allium Emporium” is our pet name for the upstairs barn (an old, well ventilated tobacco barn) where we hang our garlic to dry. We hope one day to have a purpose-built ground level barn where we can wheel in the carts. Meanwhile we haul the garlic in buckets up a ladder, and later haul it down again in bags! Less than ideal, but workable.

Hanging up the garlic:

Hanging garlic in vertical netting. Credit Marilyn Rayne Squier
Hanging garlic in vertical netting.
Credit Marilyn Rayne Squier
  • Start immediately to the north east of the ladder, and concentrate the garlic hanging in a narrow stretch of the netting. We want to have the garlic arranged in date order, to make it easier to find dry garlic to trim when the time comes.
  • Start at knee height and work rows back and forth, taking 4-6 ft per person. Continue upwards as high as you can reach, before moving left to another section. The netting will stretch down with the weight of the garlic. Starting lower will cause garlic to pile up on the floor.
  • People hanging garlic need to work right next to each other. We want walls covered with garlic, and arranged consecutively each day. As well as simplifying trimming, this makes best use of the fans.
  • Take a garlic plant, bend over the top third of the leaves, and push the leafy part through a hole in the netting. The leaves should open up behind the netting. They shouldn’t be poking through to the front. This gives the garlic the best chance of drying nicely.
  • Any damaged bulbs are “Use First” quality and should be laid flat on the wood onion racks to dry.
  • Set fans to blow on the garlic. In our humid climate, fans are essential.

After two-four weeks, the garlic bulbs will have cured and be dry enough to store. We test by rubbing the necks between our fingers, sensing either a dry rustling, or a slightly damp, slippery or mushy feeling. Once they’re dry we trim the roots and tops off and sort for replanting , for storage and cull ones to use right away. And compost material, of course!

Other than harvesting garlic this week, we’ve been finishing up transplanting our warm weather crops (sweet potatoes and watermelon, and replacing casualties in the tomatoes, peppers, melons.) No casualties in the eggplant this year! The okra we had direct-sown, back before the cold wet weather and they all drowned, along with our first sowing of sweet corn, so we started some okra in a plug flat to pop in when the situation improved. Now we’re on to transplanting lettuce and leeks. We love leeks! Maybe I’ll write about them next time.

Meanwhile, the 17-year cicadas are in full force. The sound ramps up in the morning, but goes quiet in the evening. We now have clumsy flying adults landing on us and finished dead adults littering the paths. I’ve seen mating pairs, neatly end-to-end with overlapped wings, and found it is not too difficult to tell the males from the females if you look.

Today we have Tropical Storm Andrea, and have had about 3″ of rain so far. A tree has fallen on our road, so we have to remember to turn left put of the driveway, rather than right, and go the long way round.