Starting seeds at home
University of Illinois Extension
URBANA, Ill. – As we get closer to spring, many people will begin starting seeds for their gardens. “If you’ve never started your own seeds before, there are several advantages to doing so,” says University of Illinois Extension horticulture educator Ken Johnson.
“You tend to get better germination rates when starting seeds indoors because you are providing them with ideal conditions,” said Johnson. “They also won’t have competition from other plants, and there should be fewer insect and disease problems.”
Starting seeds to make your own transplants can also be cheaper than going out and buying them later in the year. You also have a lot more variety to choose from when you start your own seeds compared to buying transplants from the store—hundreds as opposed to a handful when it comes to popular plants like tomatoes.
According to Johnson, starting seeds isn’t very difficult to do. “There are just a few things you need in order to get started: your desired seed, a container to start them in, some growing media, water, and light.”
When selecting a growing medium, use a seed-starting mix, not garden soil.
“Garden soil is going to have weed seeds and possibly diseases in it, as well as being very dense and heavy,” Johnson says. “That means it won’t drain as well as seed-starting or potting soil.”
Seed-staring mix is sterile and usually is made from milled peat moss, perlite, coconut coir, and vermiculite. This combination provides a light, fine-textured medium that is ideal for starting seeds.
When it comes to your container, there are a variety of different options, including plastic sheets of small containers (cell flats), plastic pots, peat pots, egg shells, toilet paper tubes, and egg cartons. Whatever you choose, make sure the container can hold your potting medium and has drainage holes to allow excess moisture to drain away.
Several options are also available when it comes to lighting. “Fluorescent grow-lights are often used, but you can use regular fluorescent bulbs, a desk lamp, or even a windowsill,” Johnson says. “If you decide to start your seeds on a windowsill, make sure it has good southern exposure and isn’t drafty.”
Once you’ve selected the seeds you want to grow, take a look at the back of the package. It should tell you when the seeds should be sown, or planted, generally a certain number of weeks before the last frost. It may also tell you how deep the seeds need to be planted.
Once you’ve gathered all of you supplies, it’s time to plant some seeds.
- Fill your desired container with your seed-starting mix. “It’s often easier to wet media before filling the containers,” Johnson says. Make sure the media is settled, and there aren’t large air pockets in the container.
- Make an indentation in the seed-starting mix to the recommended depth. Place two to three seeds inside this indentation and cover. Press the seed-starting mix down to make sure there is good contact with the seeds.
- Gently mist the seed-starting mix with water.
- The container can then be covered with plastic to help retain moisture and warmth. Remove the plastic to spray the container if the media dries out. If uncovered, you will need to water more frequently. Once the seeds begin to germinate, remove the plastic cover.
- Johnson says, “If you are starting seeds in a cool area, it may be a good idea to get a heat mat that is specifically made for starting seeds, so that the seeds will properly germinate. It will also help to prevent disease problems.”
As your seedlings grow, keep your lights three inches above the tallest plant – higher if using incandescent bulbs – and provide them with 12 to 16 hours of light a day. “It may be a good idea to get the Christmas light timer back out so you don’t have to worry about remembering to turn lights on and off,” says Johnson.
Water media as needed, making sure it remains moist. Once the seedlings produce their first true leaves, you can water with a weak fertilizer. “Once it’s time to take your plants outdoors,” Johnson says, “make sure to harden them off before you put them in their permanent home.”