March 20 marks the beginning of spring. It is a tempting time for gardeners. We have been cooped up all winter, and we want to get our hands down into the soil just as our daffodils are peeking up through it. However, early spring is not the time to plant warm season crops outside. They can be started indoors, though.
Get started with seed selection. Grab seeds for crops your family will eat and your local food bank needs. Look for varieties that mature in 90-120 days. Also look at the date the seeds were packaged. Those put together for this growing season will have the best germination rates.
Go on the hunt for pots. Yogurt containers or plastic plant 6-packs can be reused after a rinse with a 10% bleach solution. No matter what you use, make sure they are sterile and have drainage holes.
Finally, get your hands on a quality soil-less mix. Don’t grab regular potting soil. Instead, look for something that is sterile, lightweight and has very fine particles.
With all supplies in hand, it is time to plant! Follow the directions on the seed-starting mix and seed packets. A general rule of thumb is that very small seeds should be pressed into the soil while larger seeds are placed and then lightly covered with soil.
At first, your seeds will not need light. Give them warm, moist soil, and they will be happy. One way to do this is to place your pots on a tray, slide the tray into an open plastic bag and put it on top of the fridge. Add water to the tray or mist the top of the pots with a spray bottle as needed.
Once your seeds sprout, ditch the bag. Then, move your pots and their tray to a place where they will receive 12-16 hours of light per day. South-facing windows or florescent lamps will do the trick. If you use a lamp, move it up as the plants grow. Keep it 6 inches or so away. Under a lamp or close to a window, the plants must be kept moist and may need to be rotated. If you see plants leaning to one side, reaching for light, twirl them around so they have to lean back the other way.
Plants grown in seed-starting mixes free of nutrients will need some. A few days after germination, apply water-soluble house plant fertilizer at one-quarter to one-half strength. After the first few weeks, reapply the fertilizer at full strength every two weeks. Or, lightly top dress your seedlings with quality compost.
Once your seedlings develop their second set of leaves, transplant them or thin them with scissors. Either way, the goal is one seedling per pot. This way, your seedlings won’t be competing for water and nutrients. Keep your seedlings inside until mid-May or early June, then harden them off before planting outdoors.
Do you have questions about starting seeds indoors? Post them in the comments below.