One of the first crops I harvest from my garden every year are leafy green vegetables like spinach, kale, head lettuce, leaf lettuces, arugula, young leaves of Bok Choy and domesticated dandelion (along with asparagus, of course). Together, that’s one great spring salad or stir fry.
I typically begin the seeds for these leafy green vegetables indoors in March under grow lights. Then, around the time of my last frost date (mid-May), I transplant the seedlings into my garden. Many gardeners transplant leafy green vegetables 30 days before their last frost, but in my garden, that never seems to work out. Sometimes the soil is too cool, which slows growth, or a surprise killing frost appears. And then of course, the rabbits… those damn rabbits. Because these tender vegetables are a glorious buffet for Bugs and his buddies trying to fatten themselves up after a long winter when there is little else to nourish them. If I wait until May to set out the plants, the rabbits are a little kinder, because there is so much more to eat. Better safe than sorry.
Leafy greens and small, fast growing brassicas like Bok Choy can also be grown easily by seed sown directly in your garden (or in containers). But wait until your last frost date has passed, because if the soil is too cold, the seed will be slow to germinate. And watch out for birds – most leafy green vegetable seeds are broadcast on the soil surface or covered with only a dusting of soil – I’ve actually noticed Robins watching me plant and then swoop in and pick through the soil once I’ve left the plot.
Where and when to plant leafy green vegetables
Leafy greens benefit from late afternoon shade to protect them from intense afternoon summer sun and heat. Intense sunlight may cause sunscald; high heat, especially prolonged heat, can slow their growth and inhibit their development. Shade can be provided by other tall-growing plants like corn and tomatoes, fruiting shrubs, trees, a garden shed, just about anything.
By far, you’ll achieve the best flavor from leafy green vegetables during the cooler times of the growing season – spring and fall. That’s why I try and get my seedlings in the ground as early as possible in spring (keep an eye on weather forecasts) and then plant seed again mid to late summer for a fall harvest. However, there are a number of varieties of kale which can be enjoyed all season – they’re very hardy plants and one of the ultimate sources of nutrition (kale/spinach/carrot/mango smoothies rock!).
Spacing Leafy Greens
This will vary according to the mature size of each variety, or the size at which you plan on harvesting. If you prefer young greens as I do (they’re much sweeter and more tender), plant them close together to get the benefit of shading one another from excessive sun and heat. And as they mature, gently pull them out by the root and pop them in your mouth – greens can be eaten at any stage of development, even as sprouts.
Fertilizing Leafy Green Vegetables
Lettuces and small brassicas do well with just a compost feeding, but work this in before planting seed, as the compost, even a thin layer on top of the seed, may smother it. When the plants have germinated, or after you transplant seedlings, add compost around the plants (but not against them). If your soil has been depleted by a heavy feeder like corn the year before, you may want to add organic fertilizer with significant nitrogen (like guano) a week or so before planting or transplanting.
Leafy Green Vegetable Pests
Greens are very tender vegetables and are subject to all kinds of pests, especially if the plants are stressed by frost or heat. Even more deadly are rabbits, bird and squirrels. You can’t do much about the birds, but a good layer of Liquid Fence delivered every week or so keeps the rabbits and squirrels at bay. But if you’re in Deer country, you better build a fenced-in area, with a top – basically a cage. I have a gardening friend who can’t get past a few weeks without the local deer population cleaning him out.
As far as disease, the biggest problem with leafy green vegetables, is forms of mold such as downy mildew. If the early season is very wet, mildew spores coat the plants quickly, multiply, and overtake them. There are some organic solutions to combat mildew, but they must be applied before the mold infects the plant.
Once infected, don’t bother trying to save the plants – they become inedible. If your season’s rainfall and humidity is relatively normal or dry, mildews and disease in general shouldn’t be a problem. But you should always exercise caution and thin your plants as they grow, to ensure good air circulation around each plant. Compost is one of the most efficient barriers to mold spores.
As far as insect pests, that largely depends on where you live. In more moderate areas like the mid-Atlantic, insect pests are few. But in warmer regions, you might be wise to use netting over your greens. Stress on the plants is a big determinant as to their susceptibility to pests. Poor transplanting, slow seed germination, too much water, too much heat, over fertilization, etc., weaken the plant and make it an easy target. I never recommend using insecticide of any kind on your greens – in many cases, blasting your plants with a hard stream of water is sufficient to knock pests off, or they can be picked off by hand. I also recommend developing a bird habitat in your backyard – birds eat an enormous amount of insect pests and can be a gardener’s best friend. The university of Connecticut has a decent pest identification guide for greens.
When to harvest leafy green vegetables
As mentioned earlier, leafy greens can be harvested at any stage of development, but young greens are by far the tastiest. How deep into the season you can harvest depends entirely on your local weather conditions and the hardiness of the variety. Bon Appetit!