1. Are you watering the soil?
To give your seeds the best chance of germinating, you need to follow a few simple rules. First, make sure that the soil is moist but not too wet. Water it frequently and gently with a spray bottle or watering can, making sure to cover all of the soil evenly, and avoid overwatering. The soil should also be warm enough—seeds will not germinate in cold conditions—so if you live in a climate with cold winters or spring frosts, keep them indoors until the weather warms up. Seeds also need light to germinate—try putting them somewhere where they will get at least four hours of sunlight per day. Finally, if your seeds have a hard coating (as many do), they might need to be soaked overnight in water before planting: this helps soften their protective outer shell, allowing water and oxygen in so they can start growing.
2. Is the soil warm enough?
If you’re getting ready to plant seeds and are wondering if your soil is warm enough to sprout, plant a seed in a small pot. If the seed doesn’t grow within seven days, it probably isn’t warm enough.
Seeds will not germinate (sprout) until the soil is at least 70 degrees Fahrenheit. Soil temperature can be checked with a soil thermometer or by sticking an ordinary meat thermometer about 2 inches into the ground.
You can use a seedling heat mat to raise the temperature of your soil several degrees overnight, or put a heating pad under your trays or pots to keep them warm inside.
3. Does the location get enough sunlight?
Three quarters of the way through, your seedlings are starting to get a little aggressive. They’re strong and they’re tall and they’re ready to grow up…or at least that’s what they think. They’ve got the attitude of an angsty teen, the kind who insists she’s ready for her own driver’s license even though it’s clear she is not. Remember: you can’t let them rush you into this. Instead, keep your eyes on the prize (a healthy garden full of beautiful plants) and give them what they need before you move them into their final home.
The most important thing your seedlings will need by this point is more light. That means regular access to direct sunlight, ideally six to eight hours per day. If you’ve been keeping your seedlings indoors so far, now is a good time to start moving them outside for part of the day or placing them in front of an open window where they’ll be exposed to plenty of sunshine. If your seedlings are starting to look leggy (that is, long and skinny), it means that they haven’t gotten enough light; if they look weak and short or if their stems are bending under their own weight, there probably isn’t enough light either. You might also notice that your seedlings’ leaves have turned yellow or pale green—this too can indicate a lack of sun exposure.
4. Did you check to see if the seeds have a hard coating? (If so, they might need to be soaked overnight in water.)
However, if you are planting a seed that has a hard coat (such as the seeds from a tomato or squash plant), then you may need to soak them overnight in water. This will soften up the coating so the seed can sprout more easily. You can also scarify the coating by using sand paper or soaking seeds in vinegar for a few hours. Scarification is when you remove or damage part of the seed coating in order to enable germination. There are special requirements needed for each type of seed – this is why it’s important to do your research first and make sure you know what these requirements are before planting!
Try these steps if your seeds aren’t sprouting
- Water the soil by spraying it with water until moist. Don’t drench it, but give it a good soaking so the soil can absorb water.
- Place a plastic bag over the top of your seed-starting tray to seal in moisture and help keep the soil warm and moist.
- Put your seed-starting tray in a sunny window or use grow lights and set them about 2 inches (5 cm.) above your seeds when you first plant them. Turn on your grow lights for 14 to 16 hours each day and turn them off at night; this simulates springtime’s long days and short nights and tells your seeds that it’s time to germinate, or sprout into seedlings.
- Check on your seeds daily to make sure they have enough moisture in their soil and aren’t drying out beneath their plastic bag “greenhouse.” Give them more water if needed, using a mister or sprinkler bottle set to mist mode so you don’t wash away the tiny seeds or knock them out of position in their planting cells with too much force from your sprayer nozzle.