It’s that time of year: The growing season is just about upon us here in New York’s Hudson Valley. This season I’m planning a series of gardening/farmdening workshops here in my garden/farmden. I invite anyone interested in keeping posted about these to contact me and I’ll put you on my email list for notifications.
The end of February is a slow time of year in the barely heated greenhouse. I go in there to pick some fresh leaves for salads and the pickings are slim compared to the overflowing greenery that greeted me a couple of months ago. Still, by the time I’m heading back out the greenhouse door I have the makings of a fresh, green salad in my harvest basket.
Mâche, also known as corn salad or lamb’s lettuce, is what provides the bulk of these midwinter salads. Most people are hardly familiar with mâche, and usually inadvertently as a “baby green” in restaurant salads.
Mâche is a vegetable worth getting to know better. It’s not related to lettuce but looks like a small head of a loose leaf lettuce sporting dark green, spoon-shaped leaves. The first great thing about mâche is its cold-hardiness; even outdoors, it starts growing each time there’s the slightest hint of warm weather. The second great thing about mâche is that despite its ruggedness, the dainty leaves are always tender with a delicious, mild, floral flavor.
Mâche thrives best in cool weather; hot weather puts the brakes on seed germination and makes the plants go to seed. These “shortcomings” make it a perfect vegetable to sow in fall and grow through winter and on into early spring, especially in a greenhouse.
I haven’t planted mâche for years. Instead, I let plants go to seed when the weather warms in spring. The self-sown seeds then sprout all by themselves in the cool weather of later summer and provide good eating in fall, winter, and early spring, at which point the cycle repeats itself. My only job is to weed out excess plants so that mâche doesn’t take over the whole greenhouse or garden. That name “corn salad” comes from it’s being a weed in European grain fields. (In the Queen’s English, “corn” is the word for any grain.) Mâche is a welcome weed around here.
The sun is getting brighter in the sky day by day so it’s mostly lack of heat that’s holding back plant growth. Outdoors, there’s not much to do about a lack of heat. In the greenhouse, it’s time to turn up the thermostat a bit.
Thus far, I’ve let greenhouse temperatures drop no lower than 35 degrees F. During bright, sunny days, of course, temperatures push up into the 80s. A fan keeps temperatures from getting too high, which, with lows in the 30s, would wreak havoc with plant growth, at the very least causing lettuces – and mâche – to go to seed and lose quality too soon.
Adding just a few degrees at the bottom end of the temperature scale will spur growth in the newly sprouting lettuce, arugula, onion, and leek seedlings. This new minimum temperature of 40 degrees Fahrenheit strikes a congenial balance between plant growth and the cost and conservation of energy, propane in this case.
I’m not skimping on heat when it comes to germinating seeds. Seeds require more heat to sprout than seedlings need to grow. Too little heat and seeds either rot or sprout too slowly.
Fortunately, seeds need little or no light to sprout. Some people use the warmth atop their refrigerator for seed germination; the top of my refrigerator is not warm at all. Some people germinate their seeds at a warm spot in their house, such as near a heating duct; my home, heated mostly with wood, has no such oases.
Years ago I invested in a thermostatically controlled heating mat, made especially for gardening. The mat is in the greenhouse, so even if greenhouse temperatures drop to 40 degrees F., my seed flats sit with their bottoms soaking up 75 degree warmth from the mat below.