Seed Growing, Harvest and Storage

This is a synopsis of a talk given at AMMA’s Chicago ashram on Sep 30, 2017 to a crowd of 50 participants. The talk contains ruminations, advice, theory and and methodology for growing, harvesting, cleaning and storing seeds of medicinal plants.

What is a seed?  One can describe its parts:  the seedcoat or testa that surrounds the fatty endosperm–the energy reserve; the embryo consisting of nascent root (the radicle), stem and leaf (the plumule).  When water is imbibed through the seedcoat and the temperature is amenable, enzymatic reactions and hormonal changes occur, the testa softens, the radicle extends, the plumule unfurls.  However the one thing scientists have never been able to explain is how the seed bears the spark of life, or indeed what that spark of life is.  This is part of the great mystery and leads us to understand that there is of necessity more to life than science because science cannot explain life!

I was out in the field the other day thinking about the give and take of nature and collecting the Hopi black sunflower heads that were just ripe.  I knew they were ripe because the birds told me so–as soon as they start to eat the seeds I know the seeds are ripe.  So they eat some of my harvest but they tell me when the seed is ready.  Give and take.  That’s what keeps the balance in a garden of diversity. The birds would be hungry without me.  I would be misinformed without the birds.

Native americans knew how to attract pollinators into their gardens and wanted to do so, knowing that diverse pollinators meant larger crops for the native farmer.  Rocky Mountian beeplant (Cleome serrulata) was planted, a shockingly brilliant annual bush that brought the bees to the corn.  White boys plant cilantro (Corriander) (Corriandrum sativum) for the same purpose.  Pollinators come in droves, and all the beneficial insects, too.  Mature trees that serve the same function include Hawthorn (Crataegus monogyna or laevigata) which doubles as a significant cardiac medicine for herbal use.  In winter, plant chervil (Anthriscus cerefolium) to feed pollinators through the skimpy months.

I was out harvesting the ashwagandha (Withania somnifera) seed and remeniscing back to the early days when we got the seed from India and started growing it in our temperate gardens.  There was barely a ripe fruit available to save for seed prior to the first frost.  Now, here I was in mid-September and stripping thousands of ripe fruits from the progeny of those original plants and I realized I’ve been selecting ashwagandha seed for the trait of early ripeness for 2 decades.  Always I save seed from the earliest flowering individuals–I have no choice but to do so–and over time this created a strain that matures early, better adapted to temperate gardens.  So this is the way of it–the seed grower is always selecting plants to do well under the conditions that prevail in their garden.  Of course, the intentional side of this is 2-fold:  rogue out plants that don’t exhibit desirable traits, and always select for vigor.

So, understanding that one is operating under these influences:  cooperation with nature, a wish to integrate with pollinators and other garden life, an almost automatic influence of garden environment on plant breeding, the ability to rid oneself of plants that don’t live up, the positive influence of always promoting the most vigorous plants and choosing the most vigorous for seed stock, so within the context of all this, here are some things I’ve learned about growing plants for seed.

Grow with lots of elbowroom.  Always keep in mind human access and how easy it is going to be to keep it clean and weed-free around the seed plants, with ease of harvest in mind when planting the seed or setting the seedling out to field. Critical.  The reality is you’re going to get more production from a very few well-grown plants than from a whole slew of poorly grown plants.

Get an early start.  Organic greenhouse is way better than cold frame.  Can be heated, or just left to be heated by sun and ward off frost, to extend season both in spring and fall. I start my tomatoes in mid-March so that they are just at their maximum size and pre-flowering before setting to cages after the soil warms up, and I have tomatoes midsummer to frost, way earlier than most folks.  To get seed harvests from many of the standard medicinal herbs, for example basil, you really need to make use of every bright warm day out there and strip the seeds just before the fall freeze.  That gives maximum production of absolutely ripe seeds.

I literally PREEN my plants for seed harvest, removing weeds multiple times, keeping them cultivated, watered, well primped.  If I don’t remove the weeds during the summer, the plants don’t get as big, nor produce as fat or viable seed, and I’ll still have to weed them anyway before harvest, lest a bunch of seed seed get mixed into the sample.  Therefore, I weed early and often and get a clean harvest.

That harvest may not occur all at once.  Many species must be “milked” over a period of time.  One that comes to mind is wild lettuce (Lactuca virosa).  Every morning, a new set of bright yellow flowers gives way to seeded puffballs.  By afternoon the seed is ripe and dry and ready to fly–I have to shake the seedhead into a bucket and then collect the seed.  It is a small amount that is made each day.  I shake the plant each day, and eventually milk 10 or 20 grams of perfect seed from the plant.  Ongoing harvest–it is a reality–if you see ripe seed out there, don’t wait until tomorrow, it will fly away, or be lost to you in any of a thousand ways–collect it, accrue it, put it together as the lot number for that species for that year, dry it properly and combine it, winnow and blow and pray over it, and in all, it will be really good stuff.

To harvest, you’re going to be shaking seedheads into a bucket (e.g. hyssop), or if the seed does not easily shake out, then stripping the seedhead from the plant (e.g. marshmallow).  After that, it seems like invariably, there is a lot of rubbing involved.  Rub between the hands or on screens.  Look at my hands, they are rubbing machines, callused from rubbing!  So many times you wind-winnow your seed and then find that the seed (the nutlet) is still attached to the dried corolla (the flower) and you just have to rub the entire mass and winnow it again to get the pure seed.  A good example is German Chamomile (Matricaria chamomilla) where the first rub is going to look yellow because of the dried corollas that are present, and if the seed is really sufficiently purified, then it is colored gray, the color of the actual seed, the nutlet.  Another good example would be feverfew (Tanacetum parthenium), where the finished seed is much denser and really not as pretty as seed poorly rubbed.  It makes the difference sometimes between a professional sample (pure seed, well-rubbed) and the work of a beginner (full of chaff).  The chaff is necrotic matter, you want to get rid of it or it will infect the seed lot, good seed is properly cleaned, pure–this gives it the greatest longevity.

Watch the field dryness near the end of the growing season.  You want to be able to dry off the field before the main harvests (for example all your Mediterranean perennials–hyssop, lavender, savory and the like) or even elecampane (Inula helenium) and certainly calendula (C. officinalis) lest the seed just get gummy or rotten or moldy or just won’t shake from the capsule.  You gotta be able to dry down the field.  That’s an advantage of living in Southern Oregon where we get the real dry summers–good for seed growing!  In the midwest, like here in Chicago, you-all need to watch for bright dry afternoons and get out there and pick at that time, because otherwise morning dew, humidity, thunderstorms–these things are going to adversely effect seed quality.

Tools of the trade for seed cleaning.  Graduated stainless steel screens–a must!  Put your newly harvested seed sample in a screen that is too small of mesh for the seed to fall through, shake it, and this will get rid of all the small debris and dust.  We call it dedusting.  Work over a cotton sheet you’ve spread on the ground and put the seed in a screen that allows the seed to fall through, give it a shake, and let the seed fall on the sheet.  Large chaff will stay behind in the screen.  Some other chaff is going to blow away in the wind.  Keep working it that way.  Eventually, pour the seed on the PIZZA PAN.  Very important.  Now you can move the seed back and forth and see that some chaff is left off to the side and PUFF, you blow it off.  You can shake the seed and the chaff is going to ride up on top of the sample and again PUFF you blow it off.  Your life force through your breath in holy communion with the life force of the seed.  It is the way of cleaning.  Breath.  Prayer.  PUFF!

Seed in fruits like peppers, tomatoes, madder, poke, ashwagandha, even hawthorn berries–these need to be extracted with a different technique.  Smash soft fruits in a cloth bag until they are thoroughly mushed, then put in a bucket of water, stir, decant off the flesh and unripe seed, all floating debris, and what you have in the bottom of the bucket, after putting in more water and decanting repeatedly–is clean, viable seed.  Peppers and tomatoes need to be fermented in the bucket for several days–stir with a dedicated stick–until the seed becomes squeaky clean, and then decant and in the end pour, pour it off into a screen and set in in a good warm place, well ventilated, and stir frequently, until after a day or two the seed is dry.  Then, dry it some more before germ testing and packaging.  Quality seed can be produced in this manner, completely free of any debris, completely free of immature or poorly germinating seed, the quintessence of the quintessence.

All seeds that are cleaned and rendered free of contaminants should then be left out for several days at room temperature and further dried, cured, cleansed with breath blown over the top.  This should be done before weighing and setting to storage.  This assures longevity of the seed sample.  For dried seeds, at least.  Those that are to be kept fresh and cold-stored are put into moist peat or coir in plastic bags or jars in the fridge.  For example, cascara sagrada or goldenseal.  These do not withstand dry storage, must be stored in fresh state.  Most medicinal herb seeds are going to work well stored dry, though,  lasting 3 years in reasonable storage.  Keep seeds in cloth bags if possible, in an environment of low humidity and low temperature.  If you add up the relative humidity (say 35%) and the temperature (say 60%) and the sum of those figures (in this case it would be 95) is less than 100, then you have good seed storage conditions.  If more than 100, not good.  Most home growers will want to store their seeds in paper packets in a sealed glass mason jar in the fridge.  This is a good technique.  Freezing seeds in the freezer is not advised, don’t do it.  In any case the life span of seeds varies significantly.  Valerian (Valeriana officinalis) only remains viable for 2 years regardless of how well you store it.  Yellow dock (Rumex crispus) has been shown to remain viable for a century, even when stored in moist soil in cattle pasture.  It comes up when its ready, when it needs to, when it is needed…

Growing and cleaning seeds, you are distilling the essence of life, connecting to the divine.  Perhaps we cannot explain the life force, but with grace, we can hold it in our hands.

Richo Cech, Strictly Medicinal Seeds