Provide Light for Seedlings
Seedlings and transplants need ample light. Even a bright southern window may not be bright enough to keep your plants stocky and sturdy. Supplement with an ordinary shop light using a fluorescent bulb. Keep the bulb close -- just a few inches above the plants.
Help Heat-Lovers Germinate
Some seeds, including tomatoes and peppers, need extra-warm soil to germinate. You can provide gentle bottom heat by setting them on a horticultural heating mat or by using a thermometer to locate the warmest place in your home. A spot near the ceiling is often several degrees warmer than table height, for example.
By this time of year the anticipated yard and garden chore list can begin to get long, ranging from must-do repairs to special installations, such as patios and fish ponds. Spend some time now planning a schedule and budget for the upcoming season.
Rootbound houseplants send roots through the drainage holes, need more frequent watering, and may even stop growing. Use a soilless mix or potting soil that is similar in texture to the original soil, and step up just an inch or two in pot diameter at a time. Root prune or loosen any encircling roots to help them grow outward into the new soil.
Protect From Frost
Early transplants may need frost protection on cold nights. Use a floating row cover or frost blanket from the garden center or mail-order catalog (especially helpful if you have a large area to cover), or improvise with household bed sheets, over-turned cardboard boxes, flower pots, milk jugs, and so on. Plan ahead so you'll be prepared.