Gardening Articles: Flowers :: Annuals
Gardeners: Start Your Seeds! (page 2 of 3)
by Bruce Butterfield
4. Transplant Seedlings
When seedlings produce their first set of true leaves, it's time to transplant them into larger containers. Transplanting gives plants room to grow and improves air circulation. It also stimulates the growth of bushier feeder roots.
Fill the transplanting flat (or other larger container) with moistened growing medium. I recommend you use the same soilless mix used for germinating the seeds. Firm the mix to within 1/2 inch of the top of the container. I use six 2- by 2-inch plastic six-pack pots in each waterproof tray.
I make a planting hole for each seedling with my finger, then use a small pointed plant marker stake or wooden popsicle stick to lift seedlings. I hold each individual plant by its leaves rather than by the stem, using the stake to lift the roots as I gently pull the plant up.
Keep the rootball intact when setting the plant in its new spot. Most plants can be set slightly deeper than they were growing in the germination flat.
Firm the soil over and around the newly set plant so that the soil and roots are in close contact and there are no air pockets.
Set the transplants back under the lights unless they wilt or droop. Droopers go in a shady, cool spot for a day until they perk up.
5. Grow to Size
Check your transplants every day by feeling the soil surface. It should be moist but not soggy. Watering from the bottom directs the water to the root zone and prevents puddling on the soil surface, which could lead to damping-off. It's also less messy. I give the plants a drink of room temperature water every three or four days; more often as they get bigger.
Plants without enough light will be weak and leggy. As with the seedlings, I use four fluorescent lights above each flat and tape reflective mylar to the front and back sides of the fixtures to maximize the light directed to the plants. As the transplants grow, I increase the distance between the top of the plants and the bulbs to about 2 inches so that the light can spread more evenly over the flats.
I grow transplants at the same temperatures that the seedlings were grown: 60 to 70°F during the day, with temperatures 10 degrees lower at night. You can slow down fast-growing plants by lowering the temperature while keeping light levels high.
Transplants do best when the relative humidity is between 50 and 70 percent. Maintain humidity levels by misting plants with a sprayer, setting flats on top of trays filled with pebbles and water or covering your light setup with a plastic tent. Don't keep them too cooped up, though. I give transplants a little exercise to toughen them up by having a fan lightly blow on them. A fan can also help prevent green algae or mold from forming on top of the soil surface.
I give transplants a constant, lean diet every time I water them. Use one-quarter the recommended amount of fertilizer per gallon of water.