How to start plants from seeds
When I first started gardening I had no idea that not every seed needs the same care to grow.
For example, I couldn't get pepper seeds to germinate the first year I tried. Instead of giving up, I researched and learned that peppers love heat and germinate best when placed on a seedling heat mat. So I invested in a nice heating mat the following year and I've had great success with pepper seed germination.
I also had horrible germination with salad greens like lettuce, spinach, kale and collards. These crops still do best for me when I direct seed them. However, I like the idea that I can get an early start by starting them indoor and transplanting. So I learned and now have good success with indoor germination for these crops.
So how do you start seeds in pots or trays?
First, if you haven't read the "why and when to start plants from seeds" I encourage you to check that out. It details all the good stuff about finding your growing zone, first and last frost dates and when to start different crops.
Starting plants from seeds is easy. Don't make it more complicated than it needs to be.
Here are some supplies you will need.
potting mix or seed starting mix. I use potting mix with great results.
containers to plant your seeds in. You can use recycled plastic sour cream, yogurt, ect. containers or spend few dollars and seed starting cells. Make sure to have drainage holes on the bottom of the container. You can easily add drainage holes with a drill or with a nail and a hammer.
a plate or tray to put the pots/seed starting cells in.
plastic bag or a dome
labels and permanent marker. I love cutting the lids of sour cream and yogurt containers in to strips and using that for labels.
sunny window or grow light/shelf.
Step 1: pre-moisten the seed starting mix or potting soil so it feels crumbly and moist.
Step 2: fill the seed cells or pots with soil and press down firmly. Add more soil so its almost to the top of the container. Don't press down again.
Step 3: Sow your seeds. The rule of thumb is you should bury the seed twice the depth of its size. So if a seed is 1mm long, bury it 2mm deep. You can use the tip of a pencil to gently push the seed in to the soil and cover it. As for how many seeds to plant per pot, I never just sow 1 seed per pot. I always sow 2-3 seeds and I can always thin them later.
Step 4: Make a label with the name of the plant and the date you planted them.
Step 5: gently water the soil from top to get the seeds to settle down and make good contact with soil.
Step 6: Cover the pots/seed tray with plastic grocery bag, dome, ect. This keeps the moisture and heat in and it aids with germination. When you see half the seeds have germinated, remove the cover.
Step 7: place the tray in a well ventilated space in a window that gets direct sunlight or under grow lights. If its a heat loving crop like tomatoes, peppers, squash, and corn, you may want to place them on a seedling heat mat for better germination.
Step 8: Water when the top of the soil is completely dry. You won't need to water while the dome/cover is on. Bottom watering is basically you pour water in to the tray and the soil soaks up the water through the bottom. when the soil on top of the cointainer looks moist, you can pour the excess water out from the tray. Don't let your pots/cells sit in water.
Step 9: Once the seedlings pop up, make sure to keep the grow lights very close to their top leaves. If they aren't close enough to the light, they will start to stretch and become leggy and weak. If you are using a window that has direct sunlight coming through, you need to turn the tray once or twice a day.
Step 10: start fertilizing the seedlings after they have grow their true leaves (leaves that look like that of an adult plant of its variety). You can use any water soluble fertilizer and follow the directions on the container and use the solution to bottom water like you do normally.
And that's it.