One way to reap an abundance of vegetables from even a tiny garden is to keep planting throughout the growing season. Soon, you could be filling in new vegetables where you’ll have harvested onions or pulled spent pea or cucumber vines. Later, there’ll be space where corn, early beets or carrots have been harvested.
A good way to fill in land that opens up is with transplants. They’re less likely than seeds to get lost or neglected in the sea of vegetation in any garden this time of year. And since their first three to four weeks of growth takes place outside your garden, the harvest from transplants comes along that much sooner.
It’s not hard to grow lots of transplants in a small space with minimal labor. For instance, I can grow a month’s supply of lettuce transplants in about a square foot of space. The lettuce is ready to eat less than a month after I plant it out in the garden, and the time it takes me to grow and care for the transplants is less than 10 minutes.
The first step is to sprout the seeds. I do this in a small seedling flat, a rectangular plastic container 2- to 3-inches deep, with sides 6-inches long by 4-inches wide. Any 2- to 3-inch deep container, such as a yogurt container or cut-off milk carton, would work if you punch holes in the bottom to let water drain out. Fill the container with potting soil, sow the seeds to the correct depth, firm the soil, then sit the container in a pan of water for 15 minutes, until moisture is drawn in from below. Covering the container with a pane of glass or plastic keeps the inside moist.
Let light in
Once seedlings poke through the soil, they need light — not hard to find this time of year! After a couple of days in the sun, the new leaves are large enough to handle, and it’s time for what British gardeners call “pricking out,” the transfer of sprouts from their crowded germination flat into individual cells, for what the Brits call “growing on.”
Seedlings could grow on in a variety of containers or flats. I like seed-starting units consisting of individual planting cells that sit on a capillary mat, which draws water up from a reservoir below to water each cell. About a square foot of space houses 24 transplants. The capillary watering systems free me from watering — except to fill the reservoir every week or two — and root trauma is avoided because each plant’s roots are confined to its own cell.
Whether using a capillary watering system or some other container for growing on, fill it with potting soil — not straight garden soil — and then slightly firm it in place. You now need a “dibble,” a tool you can buy or make by putting a point on a half-inch dowel. Poke the dibble into the potting soil in a cell, give it a twist so it doesn’t stick (an advantage of a smooth plastic dibble), then pull the dibble out, thus creating an inviting home for a young seedling.
Now go to the seedling container, slide a butter knife underneath the seedlings and lever the soil up with the knife. The goal here is to loosen the seedlings from each other and the potting soil. Very gingerly, grab the two little leaves of a seedling and lift it free. Lower its roots into the waiting hole and then gently press the soil around it. After you’ve finished all your pricking out, water the plants immediately, using a fine spray, and then straighten up any that get matted to the soil.
Two hazards present themselves during and immediately after pricking. The first is stem damage. You probably noticed how delicate the stems are; accidentally squeeze or kink a stem, and the seedling will die. That’s why you hold the seedlings by their leaves. Drying out is the second hazard. New roots grow quickly, but until they do, water lost by leaves cannot be replenished. So do your pricking out indoors or in the shade, and then give the seedlings a day in the shade to settle into their new home before moving them into the sun.
After about a month of growing on in summer, transplants should be ready to pop into holes in your garden when space becomes available. Water these transplants regularly for the few days it takes their roots to reach out into surrounding ground.