To prepare seedlings for planting outdoors around mid-May, plant seeds eight weeks earlier indoors in mid-March. 

1. Place lightly dampened potting soil in rectangular plastic trays.  

2. Sprinkle seeds approximately 1/4” apart in the damp soil. 

3. Cover with 1/8”- 1/4” layer of loose soil on top of the seeds.  Do not pat it down.

4. Place trays on top of a radiator; it will act as a simple incubator. 

5. Prior to germination, keep the soil damp by misting with a spray bottle or lightly watering while not disturbing the seeds. 

The seeds should germinate in about 10-14 days, producing two leaves. 

6. Once most of the seeds germinate and produce leaves, it’s time to thin them so they are approximately 1” apart. To do this, pinch off the stems of excess seedlings so that you have approximately 1” spacing between seedlings.  

7. Place the trays in a sunny window so the seedlings get plenty of sunlight.  Morning sunlight is best, if possible.

8. Regularly water the soil to keep it damp.

9. The first leaves of the seedlings will be rounded in shape.  After a week or so, true leaves will form making them ready for transplanting. The true leaves have jagged edges, different than the rounded edges of the first leaves. 

Transplant seedlings into individual pots, 3-4” wide – one seedling per pot.

10. Continue watering the seedlings indoors with access to sunlight. 

11. To transition from indoors to outdoors, seedlings have to be ‘hardened’ so they can withstand the harsher outdoor conditions such as wind, rain and constant sun. About two weeks before planting the seedlings outside, progressively acclimate them to the outdoors by first placing them outside for one hour, either in a spot with morning sun or in a shady spot. 

12. Increase the length of time outdoors until the seedlings spend the entire day outside, as well as a few hours in the evening.

Now the seedlings are ready to transplant to a well-prepared, sunny garden bed, enriched with organic compost. Water the seedlings and resulting tomato plants throughout the growing season. As the seedlings grow to become hardy plants, use a sturdy stake or cage to provide support.

– By Diane Neff, Larchmont Resident