You may think that early August is a terrible time to be thinking about planting a vegetable garden; but if you want to harvest late plantings of cool weather vegetables, now is the time to get these seeds in the ground.
WHAT TO PLANT In general, vegetables that grow best in cool weather are leafy greens, root crops and various members of the cabbage family. Beets, carrots, peas, chard, endive, kale, kohlrabi, lettuce, turnips, radishes, spinach, oriental vegetables like Chinese cabbage and bok choy and transplants of late cabbage, broccoli, cauliflower and Brussels sprouts may be planted in early August for fall harvesting.
My fall plantings of lettuce are healthier and better tasting than the ones I harvest in early spring. When I plant cauliflower in early spring, I get small, ricey discolored heads; when I plant for the fall, I cut snowy white heads with excellent flavor. I have similar good results with fall plantings of Brussels sprouts.
When choosing cultivars for harvesting in the cooler temperatures and shorter days of fall, look for characteristics such as cold hardiness and quick maturity. Some cold hardy cultivars for broccoli are ‘Waltham’ and ‘Green Valiant’; for Brussels sprouts there is ‘Jade Cross’; for cabbage, ‘Danish Ballhead’ and ‘Savoy Ace’; for cauliflower, ‘Violet Queen’ and ‘Snow Crown’; for lettuce there are many choices: ‘Black-Seeded Simpson,’ ‘Four Seasons,’ ‘Oak Leaf,’ ‘Salad Bowl’; for peas, there is ‘Wando’ and for carrots, ‘Napoli.’ Check seed catalogs for other recommended cold tolerant varieties.
In addition, garlic can be planted two to four weeks before the first frost for harvest the following summer. Shallots can be planted after the first frost. Don’t plant earlier because any top growth they may send up will be damaged by winter cold.
WHEN TO PLANT According to the Penn State Master Gardener Manual, the average date for the first fall frost in the York-Adams County area is October 10. The average date for the first hard frost–with temperatures of 25 degrees or lower–occur around November 10, so you have quite a bit of growing time left for vegetables that are planted in August. Spinach and other greens may even be planted in September. All the vegetables listed above can easily survive a light frost if provided with some kind of protection, and some can even make it through a hard frost.
To protect from frost, keep an ear tuned to your local nightly weather forecast during late September and early October. When frost is predicted, be ready with some kind of protection. Options range from commercially manufactured row covers, cloches, polyethylene blankets, and corrugated fiberglass covers to simple household items like used gallon milk jugs with their bottoms removed and old towels and bed sheets thrown over plants the evening that frost is forecast.
Remember that the beautiful Indian summer weather that often follows the first frost or two is some of the best growing weather of the year for cool weather plants. In his book “Square Foot Gardening,” Mel Bartholomew notes that lettuce survives some frost while spinach especially ‘Winter Bloomsdale’ holds up through several freezes and kale can happily take all the snow and ice the waning year can send its way. It is not unusual to be able to harvest root crops throughout a mild winter if they are mulched well.
HOW TO PLANT When planting seeds for your fall garden, keep in mind that conditions are different for summer planting. Rains are usually infrequent but heavy rather than frequent but light. Provide constant soil moisture for good germination and to get your plants well established. Plant seeds deeper than in the spring so they will be in a moister and cooler layer of the soil. Provide shade for any transplants until they become acclimated to the outside garden. It is also a good idea to shade newly emerging seedlings until most have germinated and/or the weather has cooled. I simply place an old piece of lattice on top of some bricks until the seeds are up and going strong.
To increase seed germination, water the planting area with a fine mist 30 minutes before you plant. This lowers the soil temperature and creates the conditions that cool-season crops prefer. If the weather is unordinarily sunny and hot, a good technique to regulate soil temperature is to water the bed well and cover with several inches of straw, then water again. You can remove the straw after a few days and plant your seeds in the cool soil.
If you’re ready for still another gardening project this year, why not try planting a fall vegetable garden. Fill in those empty spaces left behind after harvesting your peas, onions and cabbages and discarding that sad-looking lettuce gone to seed with some delicious and nutritious cool weather vegetables. If you’re lucky, and Mother Nature cooperates, you could be eating vegetables fresh from the garden along with your Thanksgiving Day turkey.