Editor's note: This is the first in a two-part series of starting plants from seed. This week will cover starting seeds indoors, and next week will cover sowing seeds outdoors.
We plant seeds indoors to give plants a head start over those that germinate outside in the ground. We already are in the midst of the season to be starting plants, or gathering and preparing to start plants. Keep in mind the timing, containers, soil mix and lighting before beginning an indoor planting project.
Timing of planting is probably the most important. Plan so that seedlings are large enough to easily transplant, but not so large that they are difficult to keep alive inside. To determine the correct time to plant, consider germination time (on the back of the seed packet), growth rate and cold tolerance of the plant. Pansies have high cold tolerance, but a medium growth rate, so they should be started now to be the right size to transplant. Spinach, which also has a high cold tolerance, grows faster, so it should not be started until late February.
Plants with no cold tolerance should not be transplanted outside until after the frost-free date. In the Lawrence area, that date is May 2, according to the K-State Weather Data Library. Tomatoes and peppers could be started in late March to transplant in early May. Faster growing crops - cucumbers, melons, zinnias and marigolds - can be started as late as mid- to late April to transplant after soil temperatures have warmed.
There are many containers available for starting seeds, or you can make your own. They simply need to be sturdy enough to hold the plants and soil, and should allow the water to drain through the soil so that it stays moist but not wet. One of my favorites is the compressed peat pellets. They swell from a small round disk to about the size of an egg. Follow the instructions that come with the pellets for a simple seed-starting method.
If you use plastic or clay containers, or shaped pots made out of peat, select a growing medium that is well-drained and fine in texture. There are many synthetic mixes available (what we commonly think of as potting soil) or you can create your own mix with soil, peat, sand, and vermiculite.
Fill the containers to within 3/4 of the top of the container with your choice of soil mix. The depth of planting is different for each plant type, so follow instructions on the seed packet to determine. It is often easiest to just lay the seeds on top of the soil, and add the proper amount of mix over the top. Very fine seeds may not need to be covered at all.
Water with a fine mist. You can then place the containers in a plastic bag to retain moisture; you should not need to water again until the seeds germinate.
Keep the containers with seeds and growing medium in a warm location, preferably 65 to 75 degrees. They do not need much light until after the seeds germinate, but watch daily for germination and move the plants to bright light as soon as they begin to grow. This is also a crucial time to keep the moisture level right. Avoid letting the plants be extremely wet or dry. Any sign of mold or fungi indicates that the soil mix is too wet.
To add supplemental light for the new plants, two 40-watt fluorescent tube bulbs will work. More importantly, keep the lights about 6 inches away from the plants, raising the lights as needed while the plants grow. The light should also be kept on for about 14 to 16 hours a day, but not more. Plants need time in the dark, too.
When the time is right, let the plants adjust to the outside and transplant! You'll have flowers and produce weeks ahead of time, if everything goes just right.