If you’ve ever tried growing plants from seed you may have come across certain common issues that may cause you to lose hope.
Although seeds have an extremely impressive hardiness to ensure their species survives, the resulting seedlings can be quite fragile. Depending on whether you’re trying to grow plants from seed indoors or outside, you may have encountered the following problems:
1. Seedlings disappear – This has caused me a lot of frustration when trying to grow outdoors. Whenever the packet says something is easy to grow and you should just scatter seeds on the ground and water it, more often than not I’ve had seedlings simply vanish on me. This especially with lettuce and other greens.
Possible causes: Birds, slugs and other animals who have a taste for succulent new growth.
How to avoid: To ward off birds, consider putting netting over young plants, if slugs are your problem (there are slimy tracks all over your seed bed), look into the various methods of slug control before trying again. Or sow in pots instead and transplant into soil when the plants are bigger.
2. Seedlings flop over and wilt away – quite a common problem when growing indoors or outside under glass. Your seeds germinate, and tiny plants appear. You get very excited and can already picture them once they’re big, but all of a sudden they stop growing, leaves wilt and they fall over and shrivel. You will see that the stems of the seedlings have become thin and darker at or just above the soil level.This problem is called “Damping off”.
Cause: various fungi present in the air or soil attack the seedlings. This problem is made worse when seedlings are in a very humid environment with not enough air circulation.
How to avoid: If you have to start your seeds indoors, for example for early sowing of tomatoes before the last frosts, let the seedlings breathe! You might be using a propagator with the lid on to help seeds germinate, once they appear, take the lid off! Your seedlings do NOT need a very humid environment and it just makes them more vulnerable to fungal problems.
Closely related: If you’re seeing seedlings fall over and dying but the stems look ok, you could be dealing with “Root rot”. Confirm by lifting the seedlings out of the soil, if the roots look manky and brown, that means they’re rotting. Ideally you want the roots to look white and healthy.
Ensure that the containers you’re using to grow the seedlings in has sufficient drainage. Not everything is a bog plant and consequently although most plants need enough moisture, they don’t like sitting in water.
3. Seedlings become very tall and fall over – You need 3 basic ingredients for a healthy plant: light, water, moisture. If the seedlings are getting very long and stretched until finally the stems cannot support their weight (aka: they’re getting “leggy”) it means there is not enough light and they’re struggling to reach the light by growing longer.
Cause: lack of light
How to avoid: Put the seedlings in a sunnier place, but be careful not to allow the sun to scorch them. Or if they’re already in the sunniest spot and lack of light is simply due to the weather or season, you might want to use artificial lighting. Also, if your seedlings are already leggy and you don’t want to sacrifice them, try supporting them with a bit of wire until they get stronger.
4. Seedlings wilted and died – If the seedlings have just suddenly wilted and look quite dry, chances are they’re not getting enough water. A lot of seedlings start off small with very small roots. People make the mistake of trying to water them by misting them and keeping them in a humid environment (as above, this is wrong and might cause them to rot), instead they’re meant to get moisture from their root system!
Cause: Seedlings are not getting enough water / or they’re being dried to a crisp on a sunny windowsill.
How to avoid: Water the soil, not the plant. Ideally you have grown your seedlings in seed trays sat on top of an undertray so when you water the soil, the excess can drain off. Don’t water too much though or you’ll get other problems. Keep your seedlings in a light place but remember that a sunny windowsill can get very hot on a bright day!