Sustainable gardening includes season extension: growing before the last frost of Spring and after the first frost of Fall. The normal frost-free growing season in our part of the Virginia Piedmont is 182 days, starting with the last spring frost (usually between April 20 and 30) and ending with the first fall frost, usually between Oct 20 and 30. Season extension means growing outside these dates, before the last frost of spring and after the last frost of fall. Vegetables that tolerate frost are called cold hardy; examples include cabbage, onions, spinach, lettuce and carrots.
Many of our favorite vegetables will not produce outside the normal growing season. Think of the tender summer annuals: tomatoes, basil, peppers, corn, beans, eggplant, melons and squash. Plant them too early and the frost will kill them. Plant them too late and the frost will kill them. So the question to ask is how much more can we plant this year, both tender annuals and cold hard vegetables, and when should we plant them for optimal results?
Lets start with the tender summer annuals. Basically any crop that will germinate now and grow to a mature yield before the first frost in late October qualifies. That’s about 3 months. And it includes many vegetables, all of which can be planted from seed directly into the garden. Winter squash should be planted by July 10 to mature in time but you can try yo ur luck and plant some afterwards – we do experience some warmer fall seasons. Bush beans and sweet corn can be planted through the end of July. Summer squash can be planted now through Aug 18 and cucumbers through Aug 28.
Next is a special group of cold hardy vegetables, grown from seed in a seed flat for up to 30 days before transplanting into the garden bed. (Note: this time of year it’s much easier to grow your own seedlings thanit is in late winter). Alternatively you can buy seedlings, but you can’t count on them being available early enough. This group includes cabbage family members like broccoli, Brussels sprouts, Chinese cabbage, and cauliflower. They all have the same schedule: plant out seedlings starting July 29 through Aug 18 (that means, if you are starting from seed, do it right now). These crops are not bothered by frost and you can harvest them well into late fall. Pressure from cabbage worms and harlequin bugs might be less this time of year but you can’t count on it. We’ve found that planting under floating row covers or tunnels is a great practice, and companion planting rosemary and cilantro helps too.
Finally, there is another group of cold hardy fall vegetables planted directly into the garden from seed. First, there are carrots. They can be planted now through Aug 18 and harvested all the way through winter until next spring if well mulched. Here’s a schedule for others:
– Bibb and leaf lettuce varieties from July 29 to Aug 18
– Radish from Aug 8 to Aug 28
– Collards from Aug 8 to Sep 17
– Turnips from Aug 8 to Sep 27
– Beets from Aug 18 to Sep 17 and
– Spinach from Sep 7 to Oct 7.
There are other important considerations for the fall garden, like planting cover crops, as well as cultural techniques and structures that can extend the season even further. See the full PWC Zone 7 Vegetable Planting Calendar.