My seeds are leggy and stretched. What’s wrong?
This usually means that your seedlings are not getting enough light and they’re reaching for it. Try giving them supplemental light, up to 18 hours a day, and make sure that your lights are as close to the plant as possible. Sometimes warmer temperatures can also encourage legginess. Try lowering the temperature of the room if your plants seem to have enough light but are still stretching.
My seedlings are turning strange colors. Tomato leaves are purple and Kale leaves are yellow. What’s going on?
This means that your plants are not getting enough of the right nutrients. Tomatoes and other solanaceous crops need a good amount of phosphorous to grow properly. Phosphorous is the “P” is the middle number found on most fertilizers (e.g., 5-4-3). Make sure the P value of your fertilizer is at least a three and add some nutrients to those plants. Leafy green plants turn yellow if they don’t get enough nitrogen (or they’re getting too much water which means nutrients are being leached out). This is the first number in the NPK value.
A lot of people make the mistake of growing their seedlings in soil from their garden. This can result in lots of issues, including discoloration of leaves. Check out this post about appropriate components of potting mix to learn what seedlings need.
I have little gnats flying around my plants. Is this a problem? What do I do?
These are called fungus gnats. It’s possible that the medium you’re going in is too wet. You’ll want to break up any green algae you see on the top of the seedling soil surface and back off a bit on the water. These gnats shouldn’t do much damage, but you don’t want them to continue to proliferate. Mold growing on the surface of soil can also be an indicator that things are too wet.
My plants are rotting at the base of their stem! Help!
This may be from a fungal pathogen referred to as “damping off.” Certain crops are especially susceptible, like Swiss chard and spinach. This pathogen thrives in cold wet environments so make sure you’re letting the soil surface dry down a bit before watering your plants. See more water management tips here.
Don’t see your question answered here? Feel free to ask in the comment box and get the conversation going (I’ll be sure to respond).
My plant looks ok above the soil but it barely has any roots…
This is fairly common when starting seedlings indoors and most often has to do with watering. Think of seedlings like children… when they’re little they need lots of attention but as they start to grow older they can handle more independence. Too much coddling after a certain prevents kids from learning to assert and fend for themselves.
Similarly with plants, if you always have have them saturated with water and perfectly warm during their childhood/teenage years, they won’t have a need to put out more roots to search for water and nutrients. Drying them down a little and lowering the temperature can help toughen them up. They’re much more likely to establish a solid foundation of roots that way! More on what plants need at their different stages of life in the Seed Starting 101 post.