Use Days to Harvest to Govern Your Choice of Plants

Choose crops that will mature just as the weather turns cold. The “days to harvest” on a seed packet refers to how long it takes from the time the seed germinates and sprouts leaves to the time when it’s ready for harvest. Germination can be as little as a few days to two weeks from the time you sow the seeds. Fall germination often happens quickly in our garden because of the warm soil.

Radishes are one of the fastest cool-season crops we grow. Some can be harvested in just under four weeks. I pick them when the roots are still small and tender. Don’t wait until they’re the size of a golf ball, otherwise they’ll be woody and spicy-hot.

I also grow nutritious and tasty beet ‘greens’ that can be harvested in 32 days. The beet roots take a bit longer — up to 55 days — but they tolerate cold weather. I harvest them when the roots are small and tender — the size of a golf ball. The same goes for carrots. Because our soil is clay-based, I grow the smaller carrot varieties, like ‘Thumbelina,’ which is round, and Adelaide, which reaches just three inches long.

Swiss Chard   (Photo by Nina Koziol)

Rather than grow lettuce or kale in individual pots or in a seed flat, I often ‘broadcast’ the seeds over moistened soil-less potting mix, patting them gently into the surface. Soil-less potting mix is often peat-based and dries out quickly, so I lightly spray the surface with water to keep it moist while waiting for the seeds to germinate. Want to grow kale? Click here.

When the leaf lettuce and kale leaves are about 4 inches tall, I use kitchen scissors to harvest enough for a meal. This allows the plant to sprout more leaves so you have a continuous supply until there’s a hard freeze. If you’re lucky enough to have a well-stocked garden center nearby, you may be able to purchase transplants of kale, beets or lettuce. Transplants can give you a head start on the fall harvest.

Know Your Fall Frost Date

We garden in Zone 5 which is near to the southern tip of Lake Michigan. The average date for our first fall frost is October 15. In some years, the first frost has occurred much later, even into November. Click to learn more about hardiness zones.

To plan my fall harvest, I use a calendar and count backwards from November 1^st. If lettuce seeds take a few days to germinate and 30 days to begin harvesting, that brings me back to October 1^st. However, I take into consideration that the daylight grows shorter each day in the fall. So, I begin sowing seeds in early September. Simply count backward from your first average fall frost date to figure out when you should sow seeds for a harvest of fall crops.