In the Garden
Ralph Purkhiser, Purdue University Master Gardener
It is seed-starting time. I do not just mean the winter sowing that was discussed in a column a few weeks ago. It is time to do some planting for your spring garden.
Of course, planting directly into the garden will not be possible for a while yet, but some crops will do fine in a protected environment. It is traditional to plant lettuce on Valentine’s Day. I usually plant lettuce in a cold frame. A cold frame is simply a box built around a planting bed and covered with a transparent material. Mine is covered with an old window, but I have seen cold frames made with plastic stretched over hoops of pvc pipe. These coverings protect the seed bed from cold weather and help warm the beds on sunny days. They also help hold in moisture. As temperatures increase over the next several weeks, you may need to raise the top on warm days to keep from burning the tender plants.
Another way to do some early planting is to use grow tunnels. These are essentially cold frames without the frame. The tunnels are made by stretching heavy plastic over frames, usually made of hoops of metal or pvc pipe. Tunnels may be only a few inches high, or may be high enough to walk into. The clear plastic allows for some protection from the cold and helps provide solar heat on sunny days. When we get past the spring last frost date, the tunnels may be removed and the crops will be able to grow normally.
A third option is actually a hybrid of these two methods, and one I will use. I have several existing raised beds in my garden. I will simply erect some sort of frame over the existing bed to support the plastic.
The first crops that may be planted are ones that like to crow in cool weather. Besides lettuce, you may plant radishes, turnips, kale, mustard, cabbage and other cole crops. Plant seeds at the depth recommended on the package and water the bed well before closing the top. You will need to monitor the beds to ensure they do not get too dry. Using this method, I usually have some small, tender greens for my salads by the middle of March.
It is also time to begin planting seeds to produce transplants for the summer garden. Some crops, such as onions and peppers, are slow to germinate, and need to be planted earlier than tomatoes, squash, cucumbers and other summer vegetables. Keeping the soil warm speeds germination. You may use an electric heating mat to produce the bottom heat needed. Another way to do this is to set the planting trays on the top of your refrigerator. During the germination stage, light is not necessary, so you do not need to worry that the trays get light until the young plants appear. Once they sprout, you will need to supply light by placing them in a greenhouse or in a sunny window, or by providing light from grow lights. Grow lights need to be only a few inches above the young plants, so you should have some way to raise the lights as the plants grow. Window-grown plants will naturally seek the sun and grow toward the window, so the trays will need to be turned frequently.
To raise healthy plants, start with good planting mix in clean planters. If you are using pots or trays that you have used in the past, wash them in soapy water and use a little bleach to kill any pathogens that may be there. Use a sterile, soilless potting mix. I prefer to use a planting medium that is listed as seed-starting mix. Plant the seeds as instructed on the package, water them well and monitor them frequently, and you will have plants ready for the garden by the time warm weather arrives.