When Should I Start Seeds Indoors?
This answer totally depends on what you are planning to grow! Count back from your expected outdoor planting date to get your seed planting date. This does vary by the specific plant, but 4-8 weeks is a good general range for annuals for warm season plantings after danger of frost (around Tax Day or April 15) So you can plant early spring garden plants that can tolerate cold now. Other plants like zinnias, sunflowers, marigolds, morning glories, etc. need to wait a little longer, to get an early start for mid to late April transplanting. Let us look at the details… Many gardeners choose to start their own seeds at home, rather than purchasing transplants. The advantages include savings in cost, and the availability of a much wider selection of cultivars. You can also time seed sowing according to your expected planting date so that transplants are ready when you need them. Of course, planting seeds and tending seedlings is also a terrific way to spend a winter day. You can start seeds in flats purchased from a plant supply company or garden center, you can use expandable peat pots, or you can use a variety of household items. When selecting a container to start your seeds, consider drainage. You do not want water sitting in the bottom of the container. You also want to make sure the container holds enough media that it will not dry out too quickly and will have plenty of room for roots to develop.
The potting media you use is also important. Often you can find a media labeled specifically for seeding. Look for media with both good drainage and high-water holding capacity. These things seem contradictory, but you want your soil to hold adequate moisture for seeds to germinate without drying out too quickly, but you also want excess water to freely drain from the medium. Light is often a limiting factor with starting seeds indoors. To produce hardy seedlings, you need 12 to 14 hours of light per day. Natural lighting is generally not enough. Supplement natural light using a shop type light, grow light, or indoor lamp. Make sure your bulbs match your lamp rating for fire safety.
Seed packets have planting depth and spacing listed on the back of the packet. Many seeds will germinate well at a temperature around 70 degrees F held constant during day and night. After germination, temperatures can be lowered according to the type of plant you are growing. Refer to OSU Fact Sheet HLA-6020 – Growing Vegetable Transplants for ideal growing temperatures. For many tomatoes, a day temperature between 70- and 80-degrees F and a night temperature between 60- and 65-degrees F is ideal. For additional information use OSU Fact Sheet HLA-6004, or reach out to Murray County Extension.
Managing water in seed trays can be tricky. Over-watering is a frequent problem. The seeds do not use much water until they have germinated, and seedlings are actively growing. However, the seeds need moisture to germinate. If you moisten the potting mix before filling trays or pots, you can better control the moisture when seeding. Wet until it holds together when you take a handful and make a fist, but it should not be soggy enough to drip. (Like a wrung-out sponge) Then, cover the seed tray loosely with plastic, checking soil moisture periodically. Remove the plastic once you see seedlings emerge. If you use a seed tray cover, vent, or remove when condensate becomes heavy and dripping. Some fogging is okay, but you do not want it to be overly wet. Though fertilizer labels recommend weekly fertilizer applications, an application every two is usually sufficient. The first application is not needed until seedlings are two to three weeks old and use a 1/2 rate for first application. Harden off your plants, or acclimate outdoors, a week or two prior to transplanting.
