You have planted your seeds, and are now eagerly waiting for them to sprout. You have kept them moist, provided them with light, and can’t wait for them to DO SOMETHING. One day your patience is rewarded and you see a tiny bit of green poking up above the soil. Each day it gets a little bigger, and then you start to see leaves… and then comes the question, NOW WHAT??!
If you have planted several types of seeds, you may notice that they all seem to have the same leaves. This is because the first leaves, or cotyledons, of many plants were part of the seed itself and thus are not exactly part of the new plant. They act as big solar collectors for the seedling to collect power, until enough new leaves have grown and can take over. You will see that the next leaves, the first true leaves, will appear pretty quickly, and that they will look like the leaves of a mature plant of that type . If you want to see the whole process in a beautiful time lapse video by Neil Bromhall of seeds germinating, click here.
Here, you can see the first leaves and the first TRUE leaves of a squash plant. See how different they can be?
If you are seeing a lot of seedlings popping up and you covered your pots with plastic when you planted them, then now is the time to remove it. If there are still many bare spots, it’s ok to leave it on awhile longer, just make sure the new sprouts don’t touch it. However, whatever you do is fine as long as you continue to monitor the soil moisture.
Once the first set of true leaves appear, it is time to start fertilizing with liquid fertilizer, as the plants will have used up the food reserves that came with the seed. You will need to use a weak fertilizer so as not to overdo it. (After all, many weed killers are just fertilizers that cause rampant, unsustainable growth that basically exhausts the plant until it can’t go on any longer and dies.) Click here for some tips on seedling fertilizer by Gardener’s Supply. Your local garden center can help you, too. If it seems like we are passing the buck when it comes to recommendations, well… we are. There are so many brands out there and some are better for some plants than others that it would be foolish to recommend one fertilizer for all.
If two of your seedlings are touching, then you will need to remove one of them, as plants need room to grow as well as good air circulation. The best way to do this is to snip the stem of one of them off near the soil. Try to resist the urge to pull the extra ones up, roots and all, because doing so will disrupt the roots of the one that you want to keep.
Next it’s just a matter of keeping them healthy until they are ready to be transplanted. This involves making sure they have the following things:
LIGHT. Seedlings may bend toward the light if they are on a windowsill, or if their light source is coming from one direction. Although this isn’t directly harmful to the plant, it’s best to rotate the plant trays/pots every day or twoso that they stay straight. If you have used a grow light, make sure that the plants aren’t any closer to the bulb than one inch; any closer and the leaves will burn.
WATER AND FERTILIZER: Continue your fertilizer program and to monitor soil moisture. it’s a good idea to check the soil every day and if it looks and feels dry to give it some water, but don’t overdo it. Over watering will kill a plant just as quickly or even more quickly than under watering. If in doubt, let the soil dry out a little between waterings.
GIVE THEM SPACE. When seedlings start crowding each other they need to be thinned, as described above. Eventually the young plants will need pots of their own, at which point you can follow more or less the same procedure as you did when planting the seeds:
1) Loosely fill a pot with soil
2) Water well.
3) Make a hole in the soil just deep enough for the new plant’s roots (You want it to be in the pot at the same level as it was in the seed tray)
4) Pull the seedling up GENTLY, holding it by a leaf. Don’t hold it by the stem – a plant can grow a new leaf, it can’t grow a new stem. Use a fork gently around the roots if necessary.
5) Place the plant in the hole, and water in.
6) Continue to fertilize, give light, etc.
About a week before the last expected frost date in your area, bring the plants outside during the day and bringing them back inside at night, putting them in the shade for the first couple of days and then giving them a little more sun every day after that. This is called hardening off. After the plants have been hardened off, you can plant them outside, and know that before too long you will be enjoying the fruits and vegetables of your labors!
If you have any questions about any of the material shared in these seed starting posts, please contact us! In the mean time, here is a picture of a garden that was planted entirely of annuals!