Margaret Lauterbach

Use garden harvest time to plan your planting bounty for next year

Sweet potatoes are delicious but their vines can overgrow.
Sweet potatoes are delicious but their vines can overgrow. Statesman file

Harvest time is a great time to make notes for yourself about what to grow again and what not to grow. Sweet potato vines in my garden were more vigorous than usual, so they’ve overwhelmed some crops, including my favorite chiles. Next year I’ll give chile plants more room and less competition. I’ll grow Swiss chard in a bit of shade again, since my crop was free of leaf miners this year, first time in 40 years. I’m growing heirloom butternut squash this year, but it looks like I’ll harvest only three squash from that planting. I’ll go back to Waltham butternuts next year.

In spite of our northerly location, many in this valley grow more tropical figs. Some plant them in containers, and roll them into the garage for winter storage, and others cut off all roots on one side, lay the shrub or tree down in the opposite direction and cover with fallen leaves. My fig shrubs or trees are planted in ground, situated in a protected site between the greenhouse and deck, adjacent to the house. I’ve kept them free from freezing a few winters with bags of fallen leaves each year; last winter, I didn’t protect them at all. I had an early crop of fruit for the first time this year.

I am waiting for the larger, regular crop of figs to ripen. There are ways we can force ripening. One reported way is to poke the fruit with a knife so it thinks it’s been pollinated, according to Mike Shanahan’s “Gods, Wasps and Stranglers, The Secret History and Redemptive Future of Fig Trees.” I’d think a needle jab would be preferable since fig pollinators are usually tiny wasps who poke and wiggle their way inside to the interior “flower.” Lee Reich, in “The Ever Curious Gardener,” says we can hasten ripening by putting a drop of oil (usually olive oil) on the eye of a nearly ripe fig. He says the oil stimulates the release of ethylene, a ripening factor.

Another crop usually considered “Southern” is the sweet potato. I think the main reason we consider it a Southern crop is that the post-harvest curing period calls for high temperatures and high humidity. The founder of Edwards Greenhouse, Garnett Edwards’ grandfather, raised sweet potatoes, cured them in the old house his family had lived in, and sold sweet potatoes door-to-door. He used a wood or coal stove for the curing, probably water on the stove to raise humidity. Some sources report curing requires heat of 90 degrees and 80-90 percent humidity for about 10 days. That curing is very difficult to manage in our climate. The curing process does two main things: heals wounds inflicted in harvest and allows the starches to turn to sugar.

What I’ve found is that just letting them rest for a week or 10 days improves the flavor (as it does winter squash). The starches have turned to sugar without the high humidity, but I confess I have provided solar heat in my greenhouse. Sunny days see temperatures quickly rise to 100 degrees in the greenhouse before the exhaust cooling fan comes on. Nights drop to 60 or so, so my “curing” is not consistent with usual instructions, but it works.

If you’re growing sweet potatoes, don’t dig them until October unless frost threatens, and the longer they can stay in the ground, the better. An old garden reference claims their yield doubles every two weeks of September. The vines are beautiful, and the leaves edible. Some Asians grow sweet potatoes for the leaves instead of the tubers, as shown in YouTube videos. I don’t think those leaves are palatable as raw greens, but they’re delicious in stir-fry dishes.

Digging sweet potatoes starts with cutting back on the vines to find the tubers. Then loosen the soil with a spading fork about 18 inches from the visible sweet potato tips, and pull up the plant. You’ll do less damage to those tender skins if you then feel in the loosened soil for added sweet potatoes that have broken loose from the central cluster. Sweet potatoes tend to grow vertically, and since some protrude from soil, they’re vulnerable to frost damage. I wouldn’t wait until after a frost to pull or dig sweet potatoes. Some experts warn against washing tubers; others recommend washing soil from them.

Okra is another Southern crop, and I’ve grown it before, but the past few years I’ve gotten very spotty germination. I watch the few plants I have, and when pods are 2 inches long or a little longer, I harvest them and put them (whole, unprocessed) in a baggie in the freezer. One or two at a time build up to a meal’s amount.

Send garden questions to or Gardening, The Statesman, P.O. Box 40, Boise, ID 83707.

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