he very idea of growing and eating sunflower greens began with one person, Viktoras Kulvinskas, cofounder of the Hippocrates Health Institute. A treat among microgreens, sunflower demands and deserves special attention.In part because they’re resistant to mold, sunflower and pea microgreens have been popular choices for decades. These crops discourage mold growth because their stems are thick but their canopies aren’t, which means the leaves don’t trap and hold water even when they’re watered from above. Sunflower seeds are large, which makes it harder to sow them too closely together, thereby preventing a thick canopy of leaves. Peas grow sparsely distributed leaves that amount to hardly any canopy.
Sunflower and pea microgreens all flourish when grown in either cafeteria trays or seedling trays. Because of the popularity of these microgreens, this chapter features specific details for how to grow them effectively.
he very idea of growing and eating sunflower greens began with one person, Viktoras Kulvinskas, cofounder of the Hippocrates Health Institute. A treat among microgreens, sunflower demands and deserves special attention.
Successfully growing sunflower greens means employing several techniques that aren’t recommended for most other microgreen crops. For example, the seeds are germinated inside a sprouting jar after soaking, the soaked seeds are not covered with soil, the emerging rootlets are covered with a weighted tray to encourage them to head down into the soil, and the greens are watered from above, which softens the shells and makes it easier for the leaves to shuck them off. In fact, the downside to growing sunflower greens is that some gardeners may tire of plucking the inedible shells off the leaves. However, if you follow the steps outlined in this chapter, you’ll be ensured a harvest in which no (or at least very few) annoying shells cling to the tender sunflower leaves.
This chapter features specific details for how to grow sunflower greens effectively. The following instructions will tell you how to proceed by the hour and the day.
The best seeds to use to grow sunflower greens are black oil sunflower seeds in their shells, the same seeds that are used to make sunflower oil. Sprouting and garden seed suppliers sell black oil seeds exclusively for growing sunflower greens. These retailers often stock seeds that have been bred for the specific trait of shedding shells. Generally, such seeds are very small and their shells are dark black and shiny.
If you find a source of high-quality seeds, consider reordering a large supply immediately and store the seeds in the refrigerator. In their shells, black oil sunflower seeds retain their viability for a long time.
When it comes to growing greens, black oil sunflower seeds offer a distinct advantage over the striped variety, which are mostly grayish black with thin white stripes. The sunflower kernels that we eat as snacks come from striped seeds, which are far larger than black oil seeds and also produce larger greens. But bigger isn’t always better: the striped shells are dense and thick and cling to leaves more tenaciously than the black shells. If you grow sunflower greens from striped seeds, you’re sure to lose patience since you’ll have to pluck off nearly all of the striped shells by hand.
You might wager that you can win this “shell game” by starting with sunflower seeds that have already been removed from their shells, but hulled seeds aren’t recommended for growing sunflower greens. Hulled, the seeds quickly lose viability unless they’re refrigerated, yet neither distributors nor sellers refrigerate them. If you were to try growing seeds from six or seven local or mail-order sources, you would be fortunate if just one batch of hulled seeds germinated at a rate greater than 90 percent. Many batches don’t germinate at all.
Birds especially like black oil sunflower seeds because they have a high oil content and are easy to shell. Unhulled sunflower seeds intended for wild bird feed can be used for growing sunflower greens because they sprout well, and this option may be of interest to people who are particularly frugal or live on a limited income. The downside is that the seeds come with all sorts of debris, which may include insect eggs that “sprout” into larvae. Seeds intended for human consumption are more carefully sifted and culled.
Sunflower thrives in summer heat or in warmly heated homes, but germination and growth slacken in cool temperatures. Depending on the season, your results when growing sunflower greens at home may vary. The timeline below is based on growth patterns in early summer, when noontime temperatures average 80 degrees F (27 degrees C). Note: Be sure to label the tray with the sowing date and keep notes throughout the process to document your own timeline.
HOUR ZERO: Measure the seeds. There’s no one-size-fits-all recommendation for the amount of black oil sunflower seeds to sow per cafeteria tray because the seeds vary in size and so do the trays. But here’s a potential starting point: use ½ cup (118 milliliters) of seeds, which is a suitable amount of averagesized seeds to fill an average-sized tray.
Another option is to measure the surface area of the soil in the cafeteria tray. For every 100 square inches (645 square centimeters), use no more than 4½ tablespoons (66 milliliters) of seeds. If you prefer to avoid calculations, follow the instructions for measuring on page 40.
As described in the next step, sunflower seeds must be soaked before sowing. Therefore, they must be measured before they’re soaked. But what if you sow the seeds and find you have measured and soaked too few? You can fill the remaining bare soil with a different variety of microgreen seed that doesn’t need soaking but germinates and grows at the same rate as sunflower. Napa cabbage is a good choice. Or, if you have soaked too many sunflower seeds, you can sow the excess in a pint (one-half kilo) container or two. Or just feed the soaked seeds to the birds. They’ll appreciate the free lunch and especially the softened shells.
HOURS ZERO TO 8: Soak the seeds. Put the measured seeds into a one-quart (about one-liter) widemouthed jar. A glass canning jar is a good choice, but any jar will do. Fill the jar with water and let the seeds soak for eight hours at room temperature. If you soak the seeds for eight hours, you can accelerate microgreen growth by twenty-four hours. The timing need not be exact: soaking the seeds between four hours and twelve hours is okay too. If you’re pressed for time, soaking the seeds for only one or two hours is better than not soaking them at all.
As the black shells soak and their natural colors are released, the soak water will rapidly become cloudy. Your goal is to keep the water clear, which means changing the water. To facilitate draining, screw a sprouting jar strainer lid on to the jar and pour out the water. If you don’t have such a lid, an alternative is to use pliable nylon screen or cheesecloth, either of which can be affixed to the jar with a rubber band. Another option is to pour the water through a fine-mesh strainer or colander. Once the cloudy water has been drained, refill the jar with fresh water, stir or swish the seeds around in the jar, then let it stand. If the shells continue to stain the water, repeat this procedure as often as is convenient. However, if you’re able to freshen the water only once midway through the soak cycle, that’s sufficient.
OPTIONAL: Make a plunger. Unhulled sunflower seeds float, so some of the seeds that you’re soaking are likely to rise slightly above the waterline, like the tip of an iceberg. These seeds won’t be properly soaked and won’t germinate uniformly with the others. To avoid this problem, create a plunger that will keep all the seeds under water. Simply trim a piece of stiff nylon screen or a lid from a plastic container to fit snugly against the inside walls of the jar. Put the plunger inside the jar on top of the seeds and push it down. If the plunger is sized correctly, it will keep all the seeds fully and uniformly submerged. But if the plunger is slightly loose, seeds can escape and float to the top of the water. To prevent this, weigh down the plunger with a spoon or another utensil.
HOUR 8: Drain the water. To give the seeds a final rinse, refill the jar with fresh water and drain that water too.
HOURS 8 TO 32: Germinate the seeds. You have the option of germinating the seeds (allowing them to sprout) for twenty-four hours before sowing. If you prefer not to sprout the seeds, however, you can simply sow the soaked seeds.
Germinating the seeds offers four advantages. First, the shells will soften as the seeds are rinsed, which will make it easier for the greens to shuck off the shells as they grow. Second, it’s easier to keep the seeds warm in a jar than in the soil. Third, the warmth and rinsing will accelerate growth. And fourth, sprouting a batch of seeds in advance, particularly if you’re using a new variety of seed, allows you to verify a promising germination rate before sowing. If the germination rate is low, you can discard the seeds before sowing them and avoid wasting any soil.
To germinate the seeds, put them into a jar or any sprouting container of your choice. Cover the jar with a sprouting jar strainer lid or a piece of screen or cheesecloth, as described in the soaking step (page 54). Keep the seeds warm, at least at room temperature. (Sunflowers are summer crops, so the warmer the better.) If temperatures are cool, you may need to allow the seeds to germinate for twice as long.
Rinse the seeds at least twice during the germination period, and more frequently if convenient. After each rinsing, ensure that air can flow into the jar by tapping the screen in the lid to dislodge any droplets of water. Set the jar on its side and angle it slightly downward so that any remaining water drains. Leaning the jar inside a bowl often provides the desired angle, plus the bowl catches the drainage.
HOUR 32: Give the seeds one final rinse. At about this time, a white rootlet, called the radicle, should begin to poke through the tip of the shell. This miracle of birth is particularly stunning when it involves sunflower seeds; the seeds’ large size and the high contrast between the white rootlets and black shells make the spectacle quite dramatic.
Now that the rootlets have emerged, rinse the sprouted seeds one last time before sowing. If necessary, you can postpone sowing the seeds for one more day, but no longer. If you wait too long, the rootlets will begin to bend, and after tumbling about with each rinsing, they’ll point in many different directions, preventing them from properly taking root in the soil.
DAY 1 PLUS 8 HOURS: Sow and mist the seeds. Spread the seeds evenly upon the tray of moistened soil. Don’t allow the seeds to rest on top of each other, or they’ll rot instead of taking root. Press the seeds deeply into the soil, but don’t cover them with soil. This is the exception to the rule, because soaked seeds are usually covered with soil, which makes it easier for the emerging plants to lose their shells. Inexplicably, covering sunflower seeds with soil only makes the shells cling to emerging leaves more tenaciously, maybe because dried soil acts like mortar and cements the hulls to the leaves.
After sowing the seeds, spray them with water. Use a spray bottle or mister for this task, not the sink’s pull-out spray hose, because the stream is likely to be too forceful and might disturb or move the seeds. Use enough water to thoroughly moisten the soil, but don’t use so much that puddles form.
DAY 1 PLUS 8 HOURS: Cover the tray. Put an empty cafeteria tray on top of the seeds so that the tray’s bottom rests directly on the seeds. If you can provide a top tray that’s larger than the one on the bottom, all the better, but the same size tray will suffice. Now press down on the top tray. As long as the soil isn’t oversaturated, enough air will reach the seeds to promote growth.
This step is necessary because sunflower seeds quickly lose their vigor. They send forth their rootlets, but the rootlets may lack the energy to take root. If they fail to burrow into the soil, the rootlets will wander aimlessly on top of it. The top tray nudges them in the right direction.
DAYS 2 TO 3: Keep the seeds covered, check daily, and spray if needed. Once a day, gently remove the top tray to take a peek. If the seeds and soil appear parched, spray away, although the seeds won’t likely need to be sprayed until day 3.
On day 3, the rootlets will begin to anchor themselves into the soil. Soon after, the seedlings will begin to lift the top tray. Though only slight, the gap that’s widening between the two trays will provide a clear sign that your plans for a bountiful harvest have taken root.
DAYS 3 TO 4: Spray as needed and add weight. Once a day, remove the top tray and spray with water as needed. After you return the top tray, put some weight on it to encourage vigorous growth. The specific amount of weight isn’t important. For example, put the spray bottle, the empty sprout jar, several more empty trays, or another tray filled with soil and sunflower seeds on top of the first tray. This added resistance straightens and strengthens both the stems and the roots. If the sunflower seeds have strong vigor, the added weight isn’t needed. But such resistance can neither hurt nor hinder the seeds, so you might as well add some weight.
DAY 4 or 5: Remove the weight and redirect misguided seedlings. Take off the top tray and any added weight before the gap between the two trays widens to one inch (2.5 centimeters). While the tray is off, pluck away any misguided seedlings using fine tweezers (not your fingers). Misguided seedlings include those that are blocked by other seedlings from making contact with the soil, have failed to anchor their roots, or have grown in a direction other than down into the soil. If you don’t remove the wayward seedlings, they’ll die, rot, and contaminate the healthy seedlings. This step can be a little tricky; avoid uprooting anchored seedlings whose roots have become entangled with unanchored seedlings.
DAY 4 OR 5: Expose the seedlings to light. Expose the sunflower greens to light if possible on day 4, otherwise surely by day 5. To grow lush leaves rather than long stems, provide the greens with as much direct sunlight as the season allows. Consider moving the tray outdoors so the greens are exposed to sunlight that isn’t filtered by glass or even a window screen. Direct sunlight broadens, thickens, and energizes the leaves so significantly that they pop off nearly all the shells after merely one day in the sun. Just beware of roving squirrels and skydiving blue jays who are attracted to the shells and seek a tasty treat.
It’s worth mentioning here that many large-scale microgreen farmers don’t expose sunflower greens to light at this stage; rather, they continue to keep their seedlings in the dark, which yields long stems and paltry leaves. Some farmers expose the greens to light only on the final day, which explains why their pale sunflower greens taste like iceberg lettuce.
DAYS 5 TO 7: Top water daily. It’s time to give your trigger finger a rest. The roots that previously might have been dislodged by more than a gentle misting are now securely anchored, so you can shower the sunflower greens from above with a watering can or a pull-out sprayer hose at the sink.
Put the tray of sunflower greens flat on the bottom of the sink if it fits; if not, tilt the tray so that one end rises out of the sink. Water the greens, being sure to aim the water directly at any remaining shells to fully moisten them.
Of course, avoid watering too much. Allow thirty seconds for the soil to soak up the water, then let any excess water drain away. If the tray isn’t already leaning inside the sink, lift one end and rest it along the sink’s top edge to promote drainage. After a few minutes, turn the tray around and allow it to drain from the other end too. With practice, you’ll learn to gauge how much water is needed, and you may have little or no excess water to drain away.
Day 5, 6, or 7: Harvest the greens. The optimal time for harvest ends with the first sign of the second set of leaves, the true leaves. Be on the lookout for the appearance of these two tiny leaves in the center of the large seed leaves. Before the true leaves emerge, the microgreens will be sweet and tender, but they’ll soon turn tough and fibrous. If you delay your harvest, your crop will be larger and taller, but also tough and tart.
Harvest the sunflower greens before the true leaves emerge and as soon as the leaves have cast off all or most of their shells. During the summer, when direct sunlight is plentiful, this could happen as early as the evening of day 4, but don’t harvest before the morning of day 5. This allows the sunflower greens to metabolize their sugars and starches overnight. During the rest of the year, you can more realistically expect to harvest on the morning of day 6 or day 7.
If some shells still cling to the leaves, remove them before harvesting. Simply pluck off any remaining shells by hand. It’s much more difficult to try to remove shells after harvesting.
If you plan to refrigerate the sunflower greens, don’t water the greens from above the day before harvesting because the greens won’t dry in time. If you must water, water from the side (see pages 47 to 48).
DAYS 5 TO 14: watch the waves. Sunflower seeds will produce a second wave—and even third, fourth, and fifth waves—though each is sparser than the wave before. During the second wave, the greens can total more than one-third of the amount of the first wave, and they’ll taste just as good. When the greens are grown in a cafeteria tray, the third wave will be less plentiful; by now, the nutrients in the soil will be depleted, making the crop far less palatable. The fourth and fifth waves will be stunted and inedible.
Since lack of nutrients in the soil is the problem, if you want to harvest all the waves of sunflower greens, you could add fertilizer to the seedling mix or potting soil before sowing the seeds. Another alternative is to use more seedling mix or potting soil in the first place, which means switching from shallow cafeteria trays to pint containers or seedling trays.
When growing sunflower greens in cafeteria trays, which hold only a thin layer of soil, harvest only the first and second waves, then toss the remaining mat of greens into your compost heap. Among the diurnal birds and nocturnal mammals who will savor the remaining waves of sunflower greens, none will register a complaint with the gardener.
he mature green peas of certain cultivars are used for growing pea shoots. You won’t find these in the grocery store or even the natural food store; you must order these peas, or seeds, from garden seed suppliers. The favored cultivars of green peas for growing pea shoots include field pea, sugar pea, dwarf sugar pea, sugar pod pea, snap pea, sugar snap pea, and snow pea. Take note that flowering sweet pea (Lathyrus odoratus), an ornamental flower whose shoots are considered poisonous, should not be used to grow pea shoots.
Unlike sunflower seeds, peas need not be kept in the refrigerator. They can be stored at room temperature.
Pea shoots are cultivated nearly identically to sunflower greens, but there are differences between the two. Sunflower greens thrive in heat, while pea shoots tolerate a wide range of temperatures. Lacking shells that must be shed, pea shoots demand less attention. And after their initial harvest, the second and third waves arise not from postponed germination but from subsequent cuttings of the same shoots.
The steps for growing pea shoots in cafeteria trays are roughly the same as those for growing sunflower greens. The following steps highlight the different requirements for growing pea shoots. Note that timelines for growing pea shoots won’t be the same as those for growing sunflower greens.
SOAK THE PEAS. Just as you would soak sunflower seeds before sowing, you must soak peas for eight hours (but soaking them for twelve hours is even better if you have the opportunity to change the water midway through the soaking time). This step is especially important for peas because the viable ones swell during soaking but the dead ones don’t. This means you can identify and remove the dead peas, which won’t germinate and grow into shoots, before you sow them. If at this early stage you find there are too many dead peas to bother to remove, then proceed no further. Compost the entire jarful and the rest of your supply.
GERMINATE THE PEAS. Germinating the peas before planting isn’t as critical as it is for sunflower seeds, but this step is still recommended. Depending on the cultivar, germination may take twice as long as for sunflowers.
PREPARE THE SOIL. Peas should be sowed in potting soil, not seedling mix. If you aspire to harvest second or third cuttings, add fertilizer to the soil. Alternatively, simply use more soil, which means switching from shallow cafeteria trays to pint containers or seedling trays.
SOW THE PEAS. Cover the peas with a thin layer of potting soil to ensure that the rootlets grow downward rather than helter-skelter. Any soil that sticks to the shoots as they emerge will wash off later since you’ll be watering the shoots from above. The growth stage will again depend on the cultivar and may be twice as long as that for sunflowers. For the second wave of shoots, it may be longer still.
WATER FROM THE TOP. Top watering is recommended for the early stages of growth to ensure that the peas remain hydrated. If you grow pea shoots only under indirect sunlight and in a room with stagnant air, mold might develop not on the stems or leaves, but on the peas themselves. With the first such sign, remove any infected peas and switch to side watering.
PROVIDE AMPLE LIGHT. Pea shoots don’t require as much light as sunflower greens, but pea shoots still require light, so make sure they get plenty of it. Some microgreen farmers grow pea shoots in nearly total darkness to keep them tender and blanched. However, with scant leaves and lacking chlorophyll, such shoots fall short in both taste and nutrition.
HARVEST THE SHOOTS. When harvesting pea shoots, you can count on as many as three cuttings per tray. The number of cuttings is limited only by the depletion of nutrients in the soil. As nutrients are exhausted, growth rates slacken and sweetness decreases. But until the soil is depleted, successive cuttings of pea shoots don’t diminish in quantity. As a result, peas can provide a good return on your investment if they’re planted in fertile soil.
The first cutting can be harvested after nine or ten days if the pea shoots are grown in direct sunlight, even in winter. If the pea shoots have been grown in less intense light, count on two more days until the first harvest.
Before harvesting the shoots, inspect them closely. You should see a knob at the very bottom of the stem from which two tiny leaves barely emerge. Higher up the stem, you’ll see the first set of full-grown large leaves. For the first cutting, snip the stems just above these large leaves if you intend to harvest a second or third cutting. On subsequent cuttings, snip higher up the stems. If your first cutting will be your sole harvest, snip the stems just below these leaves. Below that, the stems will be brittle and bitter.
Expect eight to ten days to elapse between each successive cutting. The optimal number of cuttings per tray depends upon the cultivar and vigor of the pea, the fertility of the soil, how high up the stem you snip, and how long you allow the shoots to grow between cuttings. The third cutting may not be as sweet, given that taste and nutrition diminish with each cutting. Also with each cutting, the distance between each cluster of leaves increases, resulting in longer stems and fewer and smaller leaves. After the third cutting, it would be a good idea to retire the tray of pea stubs to the compost heap.
Pea shoots grow not only leaves but also tendrils, which taste as good as the leaves. New cultivars have been selectively bred to accentuate their tendrils, which are the feathery tips of the stems that serve as “hands.” The tendrils reach for and grab onto immobile objects for support as the growing pea plant climbs.
Pea leaves and tendrils are delicious eaten raw and just as they are. The first two cuttings of peas deserve to be served as the sole ingredient of a plain, undressed salad. However, when they’re cooked, pea shoots are quite sweet. For the best results, steam the shoots—even the leftover cooking water tastes good.
the inside scoop: sunflower and pea
SUNFLOWER
• Use unhulled black oil sunflower seeds to grow sunflower greens.
• Measure sunflower seeds before soaking. Try starting with ½ cup of seeds per cafeteria tray. Alternatively, determine the amount of seeds to plant by spreading a single layer of seeds in an empty tray. The seeds shouldn’t touch each other.
• Soak sunflower seeds for eight hours before sowing, freshening the water at least once during that time.
• Germinate sunflower seeds in a sprouting jar for twenty-four hours before sowing, rinsing the seeds at least twice during that time.
• When it’s time to plant, fill the cafeteria tray to the rim with moist soil, sow the appropriate amount of sunflower seeds for the size of the tray, and lay the seeds evenly and thinly upon the soil. Don’t cover the seeds with soil; this is an exception to the general rule, as soaked seeds are typically covered with soil after sowing.
• Until the seeds germinate, cover the cafeteria tray with another tray. As the seedlings emerge, put some weight on top of the tray to encourage vigorous growth.
• Early in the growth cycle, use a spray bottle or mister to moisten the sunflower seeds and emerging seedlings. Switch to top watering when the seedlings are firmly anchored.
• If possible, put sunflower greens outside in direct sun before harvesting to help the leaves grow and shuck the shells.
• Harvest sunflower greens before the second set of leaves, or true leaves, appear. If necessary, pluck off any remaining shells by hand before harvesting.
PEA
• Use the mature stage of certain cultivars of green peas to grow pea shoots (buy these from a garden seed supplier).
• Soak peas before sowing. Ideally, also germinate them in a sprouting jar before sowing.
• Sow peas in potting soil, not seedling mix.
• Water peas from the top, but switch to side watering at the first sign of mold.
• Expect up to three cuttings of pea shoots per tray. Snip the stems above the large leaves if you plan on successive cuttings.