Seed Starting Pitfalls
Seed Starting Pitfalls
In a previous post we gave some tips for starting seeds. In this post I thought I’d talk about what to do if things go wrong, and places where people commonly make mistakes with their seed starting. Here are some things to look out for and try to avoid. And take it from this long-time seed starter…these things happen to all of us at one time or another, so I’ve included suggestions for remedies should any of these happen to you.
- Tall, Weak and Leggy. Plants grow faster than expected and become very tall, weak and leggy long before it’s time to put them into the garden. Avoid this by not starting fast-growing plants too early, not fertilizing until the plants are almost ready to go outside, keeping the lights close to young seedlings so that they don’t stretch for the light, and putting a fan on a timer so that the plants are strengthened by the breeze on a daily basis. After the fact: if your plants are already too tall and leggy, put them in a cooler room to slow them down, move a gro-light closer to them, transplant them to larger pots so that they don’t become too root-bound, and space them apart so that they have to support themselves. Install a fan to simulate wind if you haven’t already had one going.
- Green Algae on Soil Surface. If the top of your seed starting mix turns green and starts to get crusty, this is usually a sign that you’re overwatering. Occasionally it also indicates that the nutrient level is too high, usually because of fertilizer being applied too early. Avoid: After the seeds germinate and start to grow, begin to let the soil dry between waterings, but don’t let the seedlings wilt. Don’t begin fertilizing right away and make sure you have good air circulation. After the fact: Scrape the algae off the top gently, so that you don’t injure young roots. Top dress with a small amount of fresh seed starting mix and water when the growing media is getting dry but before the plants wilt. Install that fan we mentioned earlier so that there is good air circulation around the seedlings and unless the plants are looking yellow or pale, don’t fertilize until it’s almost time to put the plants outside.
- Plants Fall Over and Die. This is probably a fungal condition that gardeners call “damping off.” Avoid: Always use sterile containers for starting seeds along with new potting media or seed-starting mix. Never use soil from the garden or your own home-made compost. Remember that fan we’ve talked about three or four times already? At the risk of being too repetitive, a fan can help with damping off as well. After the fact: If your plants have already keeled over from a fungus it’s too late. Try to save the ones that are still upright and strong by not overwatering and doing what you can (the fan again!) to improve air circulation.
- Vines Growing Tangled Together. If annual vines such as morning glories or sweet peas are started too early they can get all twined together. Avoid: Don’t start annual vines too early and if possible, sow seeds directly where they will grow or into pots that are outdoors. To speed germination in outdoor settings soak the seeds overnight before planting. After the fact: Transplant to larger pots and keep well separated until it’s time to transplant. If the seedlings are too intertwined to separate, clip the foliage or transplant two into one pot and grow it as one plant from then on.
- Powdery Mildew on Seedlings. If your seedlings get a gray powder on the leaves it’s probably powdery mildew, which is a fungal problem. Avoid: Be sure you have good air circulation (you’d think that we owned stock in the fan company, wouldn’t you?) and avoid crowding since plants that are stressed tend to be more prone to fungal problems. Use new, clean seed starting mix only. After the fact: spray with one of the organic fungicides labeled for powdery mildew and put the seedlings outside as soon as weather conditions make this possible. Note that if young plants have mildew for a long time they can become weakened and die. If only some of your seedlings are infected, separate these and place them away from the others so that the condition is less likely to spread.
- Disappearing Seedlings. You say your seedlings disappear overnight? Even if you’re starting seeds indoors, it’s possible for them to be eaten by critters. Indoors the culprit is usually mice. Set some traps because this is one situation a fan won’t help.
Subscribe Our Newsletter
Sign up for our weekly email about sales and events.