Starting plants from seed may not be the easiest, or even the most economical, way to supply your garden. It requires investing not only a lot of time, but also money for seeds, potting soil, flats, cell packs, thermometers, those cute little markers, and perhaps heat mats, a cold frame, or small greenhouse. Regardless, the best gardeners come to it in the end. Whether it’s pride in self-sufficiency or the chance to grow varieties you can’t find in garden centers, seeds tie us to the earth like nothing else.
Peas, carrots, radishes, and greens are best direct-sowed in the garden around mid- March. But starting other seeds inside gives a jump of 10 days or longer on early harvest and bloom. Exactly when you sow depends on how long it takes the seedling to become hearty enough for transplanting outside. That occurs for spring crops, like broccoli, around April 15; plants providing a summer harvest, such as tomatoes, can go into the ground after the last frost date, around May 15.
Temperatures are tricky for tender seedlings. You can germinate on top of the fridge for ready bottom heat. (Avoid heat mats unless you’re a pro—they can fry little plants.) You can also start seeds in front of a sunny window or inside a greenhouse or cold frame, to protect the young plants from freezing, drying out, and extreme temperature changes. If you cover your flats with plastic wrap, lift it every few days and shake down the water droplets when checking the moisture of your growing medium; with a greenhouse or cold frame, open vents on sunny days to avoid burning.
Seeds to start indoors: Common vegetables and uncommon flowers
Seed Sow Grow temp. Days to germinate
Hollyhock Mar. 1 60F 14-21
Leeks Mar. 1 50-70F 5-7
Marigold “Little Gem” Mar. 15 75-80F 4-7
Nicotiana “Fragrant Cloud” Mar. 15 75F 7-21
Peppers Mar. 15 75-85F 5+
Zinnia “Benary’s Giant” Mar. 15 70F 7
Broccoli Mar. 18 77F 5-10
Cleome “Helen Campbell” Mar. 18 60-80F 10-21
Tomatoes Mar. 30 70-80F 5-10
Cucumbers Apr. 15 70F 5+
References: Southern Seed Exposure, Johnny’s Seeds, Thompson & Morgan