Grow your own vegetable transplants

Story by Rodney Wilson

If you’re a gardener, you already know that vegetable transplants, or “starts,” are fairly inexpensive and widely available. One can, with minimal investment, purchase an entire season’s plot with ease and some expectation of success after transplanting the baby plants into the ground. I’ve absolutely done it and would never judge anyone for choosing to grow their own food via this method.

Starting seedlings indoors gives you a jump-start and maximizes the growing season. Photo by Yvonne L. Bordelon.

But there are reasons to grow transplants from seeds. For starters, there’s a sense of accomplishment gained from controlling the process of growing a plant from germination to harvest. Growing your own starts can also help you control region-specific variables – for example, a Kentucky gardener can determine the exact date to plant seeds so that they’re ready when Bluegrass temperatures are most amenable to transplanting to the garden. Finally, knowing how to grow your own starts allows gardeners to save seeds from year to year, saving money and producing crops specifically adapted to the gardener’s soil and environment.   

When starting your plants from seed, the first thing to determine is the correct time to put the seeds into soil, which is determined by germination time and the frost dates for your area (we provided some of the dates for cool-weather plants in Vol. 16, No. 1, “Winter Weather Cheat Sheet”). The germination time is on the seed packet, and, for Kentucky, the last frost generally falls between mid-April and mid-May; the first frost occurs between late September and mid-October. For cool-weather crops, plant seeds to have starts ready around the last frost; warm-weather crops should be planted on a date when the weather is optimal for seedling survival and the plant will have adequate time to mature and reach harvest stage.

Transfer seedlings from trays to larger pots when they need more room to grow. Photo by Yvonne L. Bordelon.

While starting seeds inside may give you a jump-start on the growing season, average indoor conditions aren’t optimal for supporting burgeoning plant life, so you’re going to need some extra heat and specific lighting. 

The ideal temperature range for seedlings varies by around 10 degrees throughout the day, reaching higher than 75 F for a few hours midday. If you have a heated greenhouse, you can set it and forget it, but those temperatures are a bit on the high side for a lot of homes during the winter. If you’re starting seeds in a basement or living area, you can use regular heating pads (or more expensive seedling-specific growing mats – either will work) placed under the seed trays and set on low. As for the variation throughout the day (which somewhat mimics outdoor conditions), your light source will raise temperatures slightly throughout the day, and turning it off at night will reduce temps slightly, providing that curve.

You can start seeds in nearly any type of container that will hold soil (just make sure there are drainage holes in the bottom). Photo by Shane Darby.

Light from a window is generally not enough to provide the energy required by sprouting seedlings once they’ve busted through the soil, so you’ll need to rig up appropriate florescent lighting keep your plants growing steadily. Plants need overhead light, to mimic the sun, which can be achieved by either hanging the lights on a chain from the ceiling, mounting them to overhead shelves, or even attaching the fixture to the underside of a bookshelf with seedlings positioned on the shelf below. You can, of course, purchase special grow lights, but regular florescent tubes work just as well. I’ve had good luck with full-spectrum bulbs, which most closely mimics daylight.           

Another important factor: growing medium. You should purchase quality seed-starting media, which provides maximum protection against destructive fungi and bacteria. You can purchase fancy seed trays or plant in pots; I prefer old cardboard egg cartons with drainage holes in the bottom. 

After your starts are set, it’s all a matter of care. Repot or remove crowded seedlings, and move plants to larger containers when they require more space to grow their roots. After a few weeks, begin fertilizing your seedlings. There are a variety of natural and organic options available at your local garden center. You can also make your own fertilizer using various methods, e.g., compost tea, worm castings etc.

At this point, you’ll just need to water daily at an appropriate rate and check on your plant babies a few times a day to ensure no new stressors have cropped up. Keep an eye on the calendar, harden sprouts off with controlled exposure if the species benefits from that, and then put your plants in the ground after the last frost (or, for warm-weather plants, when the plant calls for it) and revel in the fact that you raised a garden from seed.




Growing transplants in a greenhouse

Photo by Cindy Shapton.
Photo by Cindy Shapton.

When transplants start to take off, but it’s not yet time to put them in the ground, it can start feeling pretty cramped. A greenhouse can relieve your living room of growing veggie starts without risking the plant lives you’ve worked since winter to maintain. Greenhouses or cold frames, when utilized at the appropriate time (usually late March to early April), collect daytime heat while protecting precious leaves from frost at night. All that heat, though, can really excite plants’ growth; if you’ll be starting your seeds in a greenhouse, you may want to delay planting by a week or two so your greenhouse isn’t overtaken by massive transplants before the last frost date.

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