March is a great time to start some seeds indoors. This can be a small project or an obsession gone berserk! Optimal light conditions, growing medium, soil moisture, temperature and timing are critical factors for success.
⢠Seedlings need at least 12 hours a day of light.
⢠Bright windows might provide enough light but can be too cold for warm-season plants such as peppers or tomatoes.
⢠If using grow lights, select bulbs between 5,000-7,000 Kelvin (K), which will help optimize early vegetative growth of seedlings. Consider LED bulbs to save on your electric bill.
⢠Select a sterile, soilless growing medium that drains well; do not use garden soil.
⢠Seeds must imbibe water to germinate. If soil medium is too, dry seed will not germinate or seedlings will wither and die. If medium is too wet, seed may rot. Vented covers for plant trays can be useful to manage moisture.
⢠Room temperature should be 60-70 degrees. If seed packet indicates a higher temperature, use a heat mat designed for seed germination.
⢠Timing information found on the seed packet will determine when you start the seeds. The third week in May is generally our last frost date; use that with the time to transplant to determine when to start the seeds.
⢠Planting containers can vary, but if you are starting more than a few seeds you may want to invest in some trays and small seed starting inserts. If you use small seed starting containers, you will need to transplant to larger containers once the seed has germinated and at least one set of true leaves has emerged.
⢠After germination, using a fan can result in sturdier seedlings, and the increased air flow can mitigate disease pressures.
⢠Seedlings need hardening off before transplanting outdoors. Plants need gradual exposure to adapt to the higher intensity and UV radiation of outdoor sunlight.
Once daytime temperatures are roughly equivalent to room temperature, gradually bring the plants outdoors, first in shade, then progressing to longer periods of direct sunlight. This is a potential failure point, as too much sun too suddenly could kill the seedling! Be vigilant in monitoring this process; if you are leaving for several hours, leave the seedlings inside.
For more information:
⢠Growing Plants from Seed â Fact Sheet #7.409
⢠Starting Seeds Indoors â Planttalk #1034
Submit gardening questions to [email protected] or call 719-520-7684. The in-person help desk remains closed for the season.
Submit gardening questions to [email protected] or call 719-520-7684. The in-person help desk remains closed for the season.
