Step-by-step recommendations for growing mighty seedlings
“From a small seed, a mighty trunk may grow.”
— Aeschylus, Greek poet, 525-456 B.C.S
A few weeks ago, I wrote about “stirring up life” by starting seeds in cell trays indoors. Now that my seedlings have developed their first set of “true,” or post-embryonic, leaves, it’s time to move them into larger living quarters to allow them to continue growing before transplanting them in April and May.
My young plants need a well-draining potting mixture with organic fertilizer that releases nutrients slowly. I’ve had good results with Rogue All-Purpose Potting Soil, which contains peat moss, organic humus, pumice, compost, sand and perlite. I’ve been experimenting by starting with one cubic foot of the potting soil and then adding another cubic foot of one part additional perlite, one part mushroom compost, and one part soil conditioner that adds more drainage-enhancement material and mycorrhizal fungi for root development.
After mixing everything together with gloved hands, I moisten the soil, but not so much that it forms clumps when I squeeze a handful. Using clean 4-inch pots, trays for bottom watering and a teaspoon, I fill the pots with soil, leaving an inch of space at the top, and I use the spoon to dig a hole in the center of each pot.
Once the pots are ready, I use the spoon handle to gently lift each seedling from the cell tray, being careful to bring up as many of the plant roots intact as possible. If I’ve done a good job of growing just one plant in each cell, I can transfer the seedling to its new home; otherwise, I must gently pry apart the seedlings. Often, one of these seedlings is more developed than the others, so I transplant the most robust seedling and use the others for compost. I keep the roots covered with the seed-starting medium to minimize root damage and transplant shock.
It’s important that the planting hole is deep enough to accommodate the seedling’s roots without bending them. Handling the plant gently, I suspend it over the hole with the roots angling down and the bottom of the stem level to the soil line. I fill in the hole with the potting soil and gently tamp down the earth around the stem. I avoid collaring the stem with a buildup of soil, so moisture doesn’t collect there and lead to one of the biggest seedling killers, a fungal disease called damping off that results from wet, cool soil and low air circulation.
After all of the seedlings have been potted, they need plenty of sunlight. I grow my seedlings in a greenhouse where they get about 8 hours of sunlight each day, and I supplement with fluorescent lights for another 6 hours a day. I’ll gradually reduce the amount of artificial light as the days get longer and the sun provides more direct light in the greenhouse.
I use a combination of top and bottom watering for my young plants. Bottom watering encourages the plants’ roots to extend toward the moisture and prevents the soil’s surface from becoming too wet. However, after a few hours, any water remaining in the tray should be poured out so the soil doesn’t become overly saturated.
It’s better to err on the side of less water than needed and to supplement with top watering. I use a watering can with a narrow, non-shower-type pour spout and sparingly water the soil surface away from the plant’s stem. Keep in mind that most plants stay healthier if the soil is kept on the dry side.
Once a week I use a quarter-strength mixture of liquid plant food for top watering. I’ve seen good results from using Fox Farm’s higher-nitrogen Grow Big plant food. For annual flowers, I use higher-phosphorous Big Bloom plant food.
Called “the father of tragedy,” Aeschylus’ plays are among the earliest surviving works by the ancient Greeks. Perhaps it’s fitting, then, that his wise words should be remembered as we avert tragedy among our seedlings so they will survive to become mighty plants in the months ahead.
Rhonda Nowak is a member of the Jackson County Master Gardener Association and teaches writing at Rogue Community College. Email her at email@example.com.