Summer Heat, and Plants for Fall

by Peter Heffelfinger

posted August 17, 2020

Summer Heat

The arrival of full-blown summer brings a rush of chores: watering early in the morning, keeping up with the waves of beans and the ripening tomatoes, or dealing with all the cucumbers and cabbages. But even amidst all the mid-summer harvest duties, little signs of the coming fall are creeping in.

The leaves on the pumpkin and winter squash plants are beginning to turn yellow and die off at the outer edges. It’s a signal to snip off the terminal buds and flowers of the vines, in order to concentrate all the remaining growth on the ripening globes. So too, for the standard tomato plants, now hung with the weight of ripe fruit: clip off any flowers at top of the vine, which will die off in the heat by the roof of a hoop house, or not have time to make fruit by autumn if they are grown outside. Note: cherry tomatoes, due to their small size and short maturing time, may continue to make ripe fruit at the ends of the vines as long as the blossoms are shielded from high heat (above 90F). And cucumbers, if given regular watering, will also continue to successfully generate small fruit at the end of the vines. The cukes may not be full-size, but they can always be used for quick, marinated pickle slices.

AK8MJH Aphids on Curly Kale

Mid-August is also when the aphids first show up on the terminal buds of the Brussels sprouts, which they did this year right on cue. Carefully folding back the tight leaves around the inner core, I doused the entire area with a mild detergent and water solution, using a small hand sprayer. After several follow-up checks, the first wave of infestation seems to have been halted. But the rule is always to keep on checking. The aphids will be back soon enough, particularly on the side-sprouts as they start to develop. And again, keep the plants watered in the heat. It’s a long way to the first chilling frost of fall, the point at which the Brussels sprouts start to turn sweet. It’s difficult to think of the traditional Thanksgiving vegetable side dish in the middle of August, but that’s part of the regimen for four-season gardening: your inner clock is always a season ahead.

Plants for Fall

While my recent transplants of cabbage, cauliflower, leeks and collards have survived the heat so far, I still am looking to fill in garden spaces that open up. At the tail end of the local nursery offerings of transplants for fall, I found bok choy, Napa cabbage, and some more cauliflower to put in once the current heat wave eases. They may bolt early, or only offer small heads, but they will still be useful even if just as mini-greens. And the garden space will be under cultivation instead of going to weeds.

As for direct seeding, I sow snow peas in late August for a quick fall crop in cool weather; as nitrogen-fixing legumes, they are an important part of the overall garden rotation plan. I will also put in some turnip seed, mostly for fall/winter greens rather than bulbs; turnips do better in the cool weather and will be past the root maggot fly season. Finally, some mustard greens will go in for a snappy addition to a salad or stir-fry.

Sometimes vegetable gardening can be seen as a horticultural chess game, thinking a few moves ahead, avoiding dangers, and working out how to get to the ultimate goal of a harvest. Except that as the chess pieces are removed from the garden squares each day, you get to eat them.

4 thoughts on “Summer Heat, and Plants for Fall

  1. Evelyn

    Peter, thanks for reminding us of what needs to be done in the garden – this post sent me off to clip the flowers high on the tomato plants.
    Is it correct that as the season moves along, the tomatoes should receive less water, which will help them to ripen faster?
    Also, do you seed any cover crops, or are all your beds full up with winter veggies?
    Thanks again for letting us follow along with you in the garden!

    1. Peter Heffelfinger

      Hi Evelyn,
      I’ve never believed that theory about withholding water to ripen tomatoes, essentially creating stress by drought. I keep them well watered, especially on hot days, in order to make plump , ripe fruit. Tomatoes are a tropical perennial vine that want to keep on growing, so the longer they thrive the longer the harvest will be extended, especially with the protection of a hoop house. Right now I am waiting for the Big Beef and heirlooms to get really ripe and sweet, but of course tasting them each day in the form of gazpacho, slices interleaved with mozzarella and drizzled with olive oil, BLT’s, etc. Neighbor gardener advised that to make them really sweet fast, dump a little Coke in the watering system. Definitely NOT going to try that!

      Yes, I do at least a third to maybe a half of the garden in a winter cover crop of standard annual rye. Easy to sow by raking it in carefully, though I protect it with row cover against the birds until the shoots are 1-2 inches high and pushing up against the Reemay. Also you can sow the rye up until early November since the Reemay also protects it against the chilly soil. There are other cover crops, such as clover, Alaska peas or special mixes, for a higher nitrogen return, but are more expensive and can be slower to germinate. Make sure it’s annual rye, not rye grass seed. Stays green all winter and is easy to till in come spring. Works in small beds or big areas. I buy it in 5 lb bags at Country Store in Mount Vernon.

      The others benefit is the cover crop traps the rain, prevents erosion and soil compaction, and acts as seasonal fallow cycle. I think of it as a winter lawn.
      Peter H.

      1. Evelyn

        Thanks so much for this thoughtful response, Peter – much appreciated! Will keep those tomatoes well-watered;-)

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