How to Grow Seedlings Under Light
Ray and Jane Goodrich
Reprinted from Potomac Valley Chapter Newsletter
There are as many methods of growing seedlings as there are growers of seedlings. This is the method that has worked for us.
1. Seed in clear plastic box with clear lid and no drainage holes. Medium: 60% barely damp peat moss and 40% perlite, any grade. Do not cover seed. Mist lightly every day. Light: 1 cool white and 1 Gro Lux. 14 hour day with 68-70 deg. daytime temperature. Seed should sprout in 10-14 days. Older seed will take longer.
If mold appears, remove with tooth pick and dust medium with Captan.
2. Transplant after first set of true leaves, about 6 weeks after seeding. Use container with drainage holes. Medium: 1/3 compost, 1/3 damp peat moss, 1/3 perlite. Carefully lift seedling with fingers and tooth pick. Place in holes about 1" apart in new medium and settle in with part of an eyedropper-full of very dilute solution of fish emulsion (at 1/4 to 1/5 recommended strength on bottle). Do not use Mer Made brand. Ortho works well.
Discard any seedlings with poor roots or chlorotic leaves. Cover container loosely. Begin admitting air the following day. This is the crucial stage. Mist lightly after cover is completely removed. Using rain water, give gentle spray daily. Do not overwater. Most failures in growing seedlings result from overwatering.
3. When leaves begin to touch, transplant again to fresh medium, as above, about 9 to 10 seedlings to a cut-off plastic gallon milk container with drainage holes. Apply dilute solution of fish emulsion. Do not saturate.
4. When plants again become crowded, transplant half to another milk container, fertilizing as above. Fertilize monthly after seedlings are in large containers.
5. In spring, after danger of frost is completely over, transplant seedlings to cold frame, lath house or sheltered bed. Mulch. Deciduous azaleas will need protection from rabbits; chicken wire is useful.
6. Keep well watered during summer months. Some seedlings will succumb. These are the weaklings. The following spring move to more exposed situation if seedlings are large enough. Discard seedlings with off-color leaves. They didn't like the winter.
Assorted "equipment": A good mister: Windex bottle washed thoroughly. A good watering bottle: squeezable plastic quart bottle with holes punched in top; fewer holes for gentler watering. Shallow cottage cheese containers for first transplanting. Clear plastic shallow containers with covers for first planting. Punch holes with hot ice pick.