Starting Seeds for Cool Season Greens 

The coldest part of winter has passed for most of us, and it’s time to start seeds for cool season greens. Late winter transitioning to spring is my favorite time of the year. That’s when I start seeds for early harvests. This article covers details for growing some of the early greens, particularly spinach and the brassicas. On Page 3 is a recipe for a veggie omelet, an easy way to get more greens into the diet.

If the garden were bare, I would have started seeds a few weeks ago. But the greens in the vegetable garden continue to offer harvests. Unfortunately, the “list of wants” from the seed catalog is far more extensive than the garden’s square footage can accommodate! It’s time for the last harvest of collards for soup; that’ll open up some space.

While we’re harvesting established cool season greens, I’ll start several new crops indoors. These plants will be plugged into the garden as space opens up. But the seedlings will not be kept in their little pots very long; this stresses the plants and causes them to bolt, or to flower prematurely. (Photo, above: dinosaur kale germinated at night; it will green up in the sunlight.)

The First of the Cool Season Greens: Spinach

Young spinach ‘Monstrueux de Viroflay’.

I would have sown spinach directly into the garden by now, but we’ve had a long run of chilly rain. The soil is so wet that it’s doubtful any seedlings would even be tempted to germinate. At this time of the year, pay close attention to the weather forecasts. Conditions could deviate considerably from the averages.

It’s not good to dig in soil this wet anyway. That would drive out air spaces and ruin the tilth of the soil by compacting it. 

As temperatures begin to moderate, slugs come out in force and will decimate any seedlings that dare to grow in this weather. Rain: good for slugs. Sluggo: bad for slugs! Organic Sluggo pellets attract and kill slugs and snails. This version of the product contains materials (iron phosphate) that add nutrients to the soil. Check the label, though; Sluggo has other products with added ingredients. The organic option is safe to use around the edibles.

Spinach From Seed Is Easy!

Spinach germinates readily, from 50°F up to the mid 70’s (soil temperature), as soon as the ground can be worked in late winter or early spring. For better chances of success, choose varieties that are disease resistant and slow-bolting. In well-prepared soil, spinach is one of the easiest crops to seed directly into the garden.

Prepare the bed by incorporating 2″ to 3″ of compost and/or aged manure into the top 5″ of soil. Spinach prefers soil pH near neutral, from 6.5 to 7.3. A soil test will indicate how much lime, if any, should be added to raise the pH.

For baby leaf harvest, sow the seeds thickly in a patch, about 1″ apart. For full-size leaves, space the seeds a few inches apart, with rows 8-10″ apart. Crowding the seeds too closely or poor soil will result in a disappointing crop.

‘Monstrueux de Viroflay’

There’s a wonderful variety called ‘Monstrueux de Viroflay’ (photos, above and below), a French heirloom dating to 1866. It grows very large for spinach, up to 20″ tall with 10″ leaves, and should be spaced several inches apart.

Viroflay, or Monster, as it is often called, is lower in oxalic acid, or oxalates, than other spinach varieties. It might be acceptable for people with health concerns that prohibit spinach consumption. Check with your doctor.

Keep the soil moist and add organic fertilizers, such as fish emulsion, Sea-Plus, or earthworm castings, every 2 weeks. In cold soil, however, liquid synthetic fertilizers high in nitrogen work better than the organics. Microbes in the soil break down organic material and make those nutrients available to plant roots. But microbes are dormant in cold soil, so they can’t perform this vital service. They’ll become more active as the soil warms up in late winter or early spring.

‘Monstrueux de Viroflay’ spinach seedlings.

Spinach Bowl

Another option is to sow seeds directly into a 14″ wide, 6″ deep bowl filled with fresh potting soil (photo, above). The pot has drainage holes. Portability allows me to bring the pot indoors on especially cold nights while the cool season greens are beginning to germinate. And moisture levels can be carefully monitored.

Since the sappy crooked pine tree that shaded the deck from afternoon sun has been cut down, conditions on the fenced-in deck are more favorable to growing vegetables in containers.

Fill the pot with potting soil to within an inch of the rim. Simply scatter seeds on the surface, a couple of inches apart for smaller varieties and a few inches apart for Viroflay. Cover with another 1/3″ to 1/2″ of soil. Water…and wait… Spinach’s two seed leaves, the cotyledons, are easily differentiated from other seedlings by their long narrow shape. Thin as necessary; you can eat the culls.

Don’t neglect fertilizing potted greens. Rain and irrigation quickly wash nitrogen out of the soil.

Harvesting Spinach

Spinach.

Harvesting the crowns begins within 4 or 5 weeks, depending on weather and soil fertility. Pick individual leaves at any age, allowing the central growing tip to continue producing new leaves. Or cut the entire plant at the soil line before flower buds begin to grow.

By sowing new crops of spinach every week or two, you’ll have continuous harvests of spinach, as long as the weather favors growth.

Spinach quickly bolts, or goes to flower, at temperatures above 75°. Dry or nutrient-poor soil stresses the plants. And spinach will flower prematurely if the plants are stressed by growing too close together.

Harvest the entire plant if you notice flower buds forming. Cutting off the flowers will not stimulate spinach to grow a new bunch of leaves. Instead, start more seeds.

Use spinach steamed as a side dish, or in sauces, soups, smoothies, salads, pasta dishes, or an omelet.

And Then the Brassicas

These microgreens are mostly brassicas.

The Brassicaceae family is a huge group of edibles. It includes arugula, broccoli, Brussels sprouts, cabbage, cauliflower, collards, kale, komatsuna, mizuna, mustard greens, pac choi, radish, tatsoi, turnip, and others.

All members have similarly notched seed leaves, or cotyledons. Those are the first two heart-shaped leaves to emerge from the seeds (photo, above). Because the seed leaves are already formed inside the seed, the little plant can begin photosynthesizing—and feeding itself—immediately upon germination. True leaves, which develop after the seed leaves, are also similar for most of the cruciferous vegetables. That’s why it’s important to label your pots so you can distinguish “this” seedling from “this other similar looking” seedling.

Include On the Label:

• the name of the crop (dinosaur kale)
• the name of the cultivar (‘Black Magic’)
• the date of sowing (brassicas germinate in less than a week if sown indoors)

Store leftover seeds in their original packets, and make sure the cultivar name is included on the label. Store in a cool, dry place, such as the refrigerator. Most seeds of cool season greens are viable for 2 years or so. If not already indicated, mark the year of purchase on the packet.

It’s helpful to keep a record of the varieties you’ve tried and liked or disliked. Include how you started the seeds (in 4″ pots or cell-packs, under lights, directly in the garden), the dates you seeded and transplanted, and the weather conditions. Include notes on what was successful and what wasn’t, and possible explanations. Did the seeds germinate and then keel over and die (damping-off disease)? Did critters eat your cool season greens as soon as they started growing? Should the seeds have been started earlier? Or later?

There are successes and failures in every gardener’s life. Being able to pinpoint the reasons for a disappointing crop will enable you to be more watchful or to try a different approach next time. Check with your local cooperative extension office, through state land-grant colleges and universities, for advice. Failure is a learning experience, not a reason to stop trying!

Damping-Off

Damping-off disease can appear soon after germination. Sometimes, diseased seedlings don’t even appear above the soil, looking as though the seeds didn’t sprout at all. The small seedling develops a narrowed brown spot on the stem. Then the top of the plant falls over, and the seedling dies. This is caused by several species of fungus, whose spores are in the air, in the soil, in the water, or on the seeds themselves.

Damping-off often accompanies:

• poor air circulation
• high humidity
• crowding
• low light
• low temperatures
• reusing old soil
• and overwatering

Space the seeds farther apart, run a small fan nearby, water in the morning, and increase the temperature and light levels if they’re low.

The first time I used the organic biological fungicide called Actinovate, life became a bit sweeter. It is costly, but a much safer option than chemical fungicides. And, with the number of seedlings I grow each year, a wise investment. Make up a small amount of the solution when needed and apply from a spray bottle or a small watering can when sowing the seeds and as soon as the seeds germinate. Always exercise caution when using sprays, and read the labels.

Caterpillars on Cool Season Greens

When the weather warms up in mid- or late spring, you’ll notice butterflies and moths flying around your cool season greens. How nice, you might think. But those lovely insects are on a mission, and that mission is to find suitable plants on which to lay their eggs.

Most of the brassicas are targeted by the female:

• Cabbage Moth (or Diamondback Moth)
• Cabbage Looper
• the velvety green Imported Cabbageworm (also called the Small White Butterfly or Cabbage White Butterfly—white with black markings). Look for them lined up on the leaf’s midrib.
• Cross-striped Cabbageworm (fine black stripes across the back, yellow stripe on the sides).
• A few other species target particular brassicas or are limited geographically.

Here in my North Carolina garden, the 1¼” long Imported Cabbageworm has been the most commonly seen caterpillar on the brassicas. It is well-camouflaged in the green foliage. But for the past couple of years, populations of the Cross-striped Cabbageworm have been increasing. They’re especially pesky when lodged among the broccoli florets. Sometimes I don’t see them until I begin cutting the broccoli (just remove them). Inspecting the produce and spraying Bt regularly takes care of that.

Eggs hatch in a few days to a week, and immediately get to work chewing little holes and then bigger holes in your broccoli, kale, and other brassicas.

Harlequin bugs on cabbage

Another insect feeding on brassicas is the black and orange harlequin bug (photo, above). I squish them when I see them, although they’ll see you approaching them and will try to hide. They cause whitish blotches and distortions in the foliage.

Bacillus Thuringiensis (Bt)

As soon as you notice the white moths and butterflies flitting near the brassicas, it’s time to get the sprayer bottle ready. The imported cabbageworm is the larval stage of a butterfly and the one you’ll see in the daytime. The other caterpillars are moth larvae and are active at dusk or at night.

Mix up a solution of Bt, Bacillus thuringiensis, available from the garden center. Dipel and Thuricide are brand names for Bt. It doesn’t take long for these voracious little caterpillars to inflict considerable damage to your plants, so don’t delay.

Spray both the upper and lower surfaces of the foliage, occasionally agitating the solution. Begin spraying a few days after first seeing the moths, or certainly when you see holes appearing. Set the sprayer nozzle to a very fine spray; larger drops of water will bead off the waxy foliage. One or two drops of dish soap in the sprayer will help the solution stick to the foliage if you can’t get a fine spray.

It washes off in the rain, but any Bt clinging on the reverse (bottom leaf surface) might be enough for the current batch of caterpillars. Spray the brassicas every 5 to 10 days, as long as the insects are active.

How Does Bt Work?

Bt is a naturally occurring bacterium that disrupts the caterpillar’s digestive system when ingested. The insects stop feeding immediately and die within a day or two. Spray as soon as you notice them because young caterpillars are more susceptible to Bt than older caterpillars.

Bt effectively rids the garden of moth and butterfly larvae, including swallowtails that eat parsley. Although they won’t bother your broccoli, black swallowtail larvae feed on parsley and its relatives in the Apiaceae family, including dill, cilantro, and bronze fennel.

The tradeoff? Fewer moths and butterflies, but more undamaged produce. I enjoy watching the black swallowtail butterflies, though, so I plant the large perennial bronze fennel for the caterpillars picked off the parsley and dill. Bt targets larvae of moths and butterflies, and nothing else.

After picking the crops, I sometimes let the caterpillars feast on the remains. Those caterpillars might feed another brood of baby birds or green anoles at that time of year. Once cold autumn weather has settled into the area, these caterpillars will no longer be around to bother the fall crop. Autumn is another delightful time to garden.

Bt is perfectly safe to use on edibles. Use up the diluted solution within a few days. Store Bt in a cool location out of the sun. Buy a small fresh bottle every couple of years, as this is a live organism, not a chemical.

Headings

Page 1: Starting Seeds for Cool Season Greens, The First of the Cool Season Greens: Spinach (Spinach from Seed Is Easy!, ‘Monstrueux de Viroflay’, Spinach Bowl, Harvesting Spinach), And Then the Brassicas (Include On the Label, Damping-Off, Caterpillars on Cool Season Greens, Bacillus Thuringiensis [Bt], How Does Bt Work?)

Page 2: Broccoli (Improve the Soil for Cool Season Greens, Harvesting and Side Shoots, When the Brassicas Bloom), Mini Broccoli (Early Sprouting Broccoli and ‘Spring Raab’, Broccoli ‘Happy Rich’, Who’s My Favorite?, Gai Lan and ‘De Cicco’, Sowing Seeds, Late Sprouting Broccoli)

Page 3: Dinosaur Kale, Hardening Off Cool Season Greens (Gradual Changes), Growing Plants Under Lights (More Tips Using Artificial Light), Getting More Cool Season Greens Into Your Diet, A Veggie Omelet Recipe Using Cool Season Greens

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