Ask Flora - Seedlings
by Sage & Snow Garden Club
April 22, 2021
My green thumb is itching. Is it too early to start seeds indoors?
Signed, Vera Pruritus
Now is the perfect time to start most seeds indoors. Seeds started now for cabbage, broccoli, Brussels sprouts, and cauliflower seedlings will be ready for transplant about June 1. Start cosmos, bachelor buttons, and alyssum seeds now for transplanting after the last frost date, about June 25. Marigolds and nasturtiums should be planted indoors about May 1 to give them plenty of time to grow before the last frost date.
How deep do I plant my seeds when I start them in the house?
Signed, Agora Plantae
Plant your seeds into the depressions at the depth listed on the seed packet. Most seeds can simply be gently pressed into the mixture; you can use the eraser end of a pencil to do so. When choosing which seeds to plant, choose the largest seeds in the packet for the best chance at germination. Water when the top of the soil is dry.
What kind of "soil" is best for starting seeds indoors?
Signed, Miles Loam
Choose potting soil that's made for growing seedlings. Do not use soil from your garden or re-use potting soil from your houseplants. Start with a fresh, sterile mix that will ensure healthy, disease-free seedlings. Before filling your containers, use a bucket or tub to thoroughly moisten the planting mix.
How do I water the new seedlings?
Signed, Rainey Downs
Water from the bottom until the seeds have germinated and won’t be displaced. Then, water from the top when the surface of the soil is dry. It is important not to under water or over water new seedlings. Too much water can cause "damping-off" disease, which is fatal to seedlings. Remove standing water from drip pans after watering.
Should I fertilize the seedlings?
Signed, Connie Post
After the first 2 leaves appear apply a very diluted liquid fertilizer. A good combination is a fish/kelp liquid fertilizer that can be diluted with water. Use ¼ the recommended amount of fertilizer and apply every week or ten days.
What kind of container can I use to plant my seeds in?
Signed, Redd S. Cupp
Plastic cups or small nursery pots are both suitable and highly recommended for planting seeds indoors. The most important factor is making sure there are small drainage holes in the bottom of the container. Peat pots are plentiful but are not recommended for growing seeds indoors because they promote unhealthy moisture problems with young plants. Toilet paper tubes and newspaper tubes can become moldy during the growing process. Egg shells are too small for proper root development.
Last year my seedlings were really tall and thin and when I transplanted them many died. How do I keep this from happening this year?
Signed, Mike "Slim" Greene
One of the most important factors for healthy seedlings is adequate light. Most homes do not have enough direct light for growing successful transplants. A grow light, either fluorescent or LED, is essential to providing enough light to prevent leggy seedlings. Seedlings need 14-16 hours of direct light every day, with a dark period of about 8 hours. The light needs to be placed close to the seedlings for best results. Another important way to prevent leggy and weak seedlings is to place a small fan on low speed in the room with the young plants. It helps develop strong stems in new plants.
Do I need to transplant young seedlings?
Signed, German Tate
Most seedlings do not need to be transplanted during the growing process unless a very small container is used to start the seeds so roots are confined and plant growth is disrupted. When transplanting to a larger container, carefully pry the plants from the container with a fork or spoon to avoid disturbing the roots.
It seems like it would be a big shock to a little plant to go from inside my house or a greenhouse to outside. If so, how can I make the transition easier?
Signed, Daisy Winters
You are right and slowly getting the seedlings used to being outside is an important step. This is called the hardening-off phase of growing seedlings for transplants. Two weeks before planting them outside, gradually introduce the seedlings to the outdoors. Start with a shady location for about 30 minutes to one hour per day. Gradually, increase their time outdoors and the sun exposure for longer and longer periods to acclimatize them to the wind, light levels, temperature and generally get them used to the idea that they will be outdoor plants soon. Common causes of failure in the hardening-off phase are too much sun too soon and not being shielded from wind.
My little kid is always playing in the dirt. How can I turn this into an educational activity? Signed, Iris Humus
Planting seeds indoors is a perfect way to introduce kids to the beauty and magic of seed germination and plant development.
For more information on starting seeds indoors, contact Arlinda McLaughlin of the Sage and Snow Garden Club at 307-231-9402. Our local Sage and Snow Garden Club is a fun way to get gardening information, meet local gardeners and help make our community beautiful. We usually meet on the third Tuesday of the month, but in-person meetings are currently suspended. In the meantime, you can visit the website, Facebook or Twitter pages. The 2021 schedule of events has been posted in case you want to participate.