Growing Seedlings Indoors: What’s the Problem?
4 Solutions for Issues You May Encounter When Germinating Seeds Indoors
By Crow Miller – Seed starting is a simple process. Though a few problems can crop up, it is not hard to avoid or correct them. Here are a few of the most common dilemmas that gardeners face when growing seedlings indoors, along with their solutions.
Problem: Seeds were sown three weeks ago and there is still no sign of life.
Solution: When germinating seeds indoors, it’s important to know that the germination rate of seeds deteriorates with age. If you have saved seed packets from top seed companies over the years, it is well worth your time to do a germination test several weeks before planting. Here’s how: Spread 10 to 20 seeds on a moist paper towel. Keep them warm and damp and see what percentage germinates. If fewer than 50% germinate within two weeks, buy new seeds. Most seeds need to germinate at a temperature considerably higher than their optimal growth temperature. Many vegetable plants will grow happily in 65°F house, but some require temperatures as high as 90°F for fast germination. Buy a soil thermometer for peace of mind about seed germination temperatures. Seed packets list appropriate germination temperatures.
Problem: Seedlings come up fine, but then they flop over and die.
Solution: These plants have the dreaded damping-off disease. There are a number of fungi and bacteria that cause damping-off. All damping-off organisms are soilborne. To avoid contamination, don’t use garden soil to start your seeds. Make your own seed starter using a mixture of sphagnum peat moss, vermiculite, perlite, bone meal, and compost. It’s easy to learn how to compost at home if you aren’t doing so already.
Also, before filling your pots and flats with the best potting soil, make sure the containers are clean, damping-off disease may be spread throughout infected containers. To be safe, wash out used containers with a 5% bleach solution. To further discourage rot, avoid overwatering and don’t let your plants get too crowded.
Problem: Seedlings are stunted and the plants are pale with yellowing leaves.
Solution: A good feeding will fix this problem. Use a balanced liquid organic fertilizer. Follow the instructions on the package. I use a fish emulsion and seaweed mix with great results. I have also had excellent results with compost tea. Beginning two to three weeks after germination, fertilize about once a week, watering the plants and the soil with the organic fertilizer of your choice.
Problem: Seedlings are tall, spindly and floppy.
Solution: The problem is lack of light. If you are growing seedlings indoors near a window, it must be south-facing and unobstructed. Even then, you still have to turn your plants regularly to keep them from getting too lopsided. A good option is fluorescent lights.
Crow Miller is co-author of Organic Gardening: A Comprehensive Guide to Chemical–Free Growing.
Originally published in Countryside January / February 2003 and regularly vetted for accuracy.