Genetics, Timely Harvest, and ?

As I led my nephew Jeff, his wife, and their two kids around the garden a couple of days ago, I plucked fruits and vegetables here and there for them to sample. They could compare them with what New York City, where they live, has to offer. They were blown away by the flavors here.
Delectable fruits & vegetables
Okay, I cheated a little. They got to sample some of the best of the best: figs so soft they were drooping from their stems, white alpine strawberries, Sungold cherry tomatoes, Golden Bantam sweet corn, and Kentucky Wonder green beans, all picked on the spot and at their peak of perfection. The Golden Bantam corn, you won’t find that offered for sale pretty much anywhere these days although it was the standard of excellence in sweet corn 100 years ago. The white alpine strawberries (Pineapple Crush) are too small and too soft for anyone to market commercially.

But genetics isn’t the whole story. Timely harvest is as important. Commercial considerations aside, it takes a certain skill to know just the right moment to do the deed.

With some plants, especially vegetables, timely harvest is easy. You pick such vegetables as lettuce, beans, and okra as soon as they’re big enough to suit you. You pick tomatoes when they’re red, which is also when I pick sweet peppers; red peppers taste quite different and, to me, a lot better than green peppers.

I haven’t grown eggplants that much over the years. This year they are particularly abundant and I’m still learning how to pick them. Full size? Glossy?

Sweet corn can also be tricky. It took me a few years to get the knack of picking it at its best. I first look for dried up silks and then, taking a tip the vegetable extension specialist at the University of Wisconsin passed on to me many years ago, I wrap my fingers around the ear and feel for fullness. That’s when it’s time to snap the ear down and off the stalk. Gauging that fulness does take practice.
Golden Bantam sweet corn, non-hybrid

Test for Ripeness

Fruits are a little trickier than vegetables, especially some fruits. Easiest of all are raspberries and blackberries. Tickle the clusters and let the truly ripe ones drop off, as they are wont to do, into the palm of your hand. Too many people tug at blackberries to get them off the plants; flavor suffers. Blueberries are similar to blackberries in that color doesn’t tell of full ripeness; the tickling method does.
Black raspberry fruit
I grow a number of varieties of two vining fruits: grapes, of course, and hardy kiwifruits. The kiwifruits, which will begin ripening in a couple of weeks, retain their fresh, green color right through ripeness. What they do do when ripe is to soften. But not all together. Fortunately, when sufficiently mature on the plant, these fruits can finish ripening after harvest. As soon as the first kiwis ripen, I pick them all. They ripen to perfection in a few days at room temperature, longer under refrigeration.
Hardy kiwifruit
Blue or red grapes seem ripe when they turn their final color. Ripe for commercial purposes perhaps, but not perfectly so. When truly ripe the whole bunch will snap easily from the cane to which it is attached. I sometimes leave the bunches (the ones I enclosed in paper bags in early summer) even longer and, to a point, their flavor just gets better and better.
Edelweiss grape
Most fruits, in fact, taste best if harvested when ready to part with the plant. That’s why for fresh eating, not storage, I sometimes harvest my apples from the ground, daily, the morning they drop. This might not be the best method for all varieties but makes for the very best Macoun apples.
Hudson Golden Gem apple
Generally, with tree fruits, I look for a change in color, especially background color, before considering harvesting a fruit. If there’s any green, I let it be. If color tells me that a fruit is potentially ready to be picked, I cup the fruit in hand, then lift and twist. If ripe, the fruit stalk readily separates from the plant. If that doesn’t happen, the fruit needs more time on the plant.

Tricky, for Me at Least

Two fruits whose harvest moment I’m still honing are watermelon and European pears.

I’ve tried all the methods with watermelon: thumping for a sound not too hollow and not to dull (the sound of knocking your knuckles against your chest as opposed to your forehead or stomach); a dried tendril opposite the fruit; a yellow-bellied fruit. They’re all guides but none are the end-all to timely harvest. I never had that problem with my large watermelon crop from my garden in southern Delaware.

Magness pear

Magness pear

European pears ripen from the inside out so become mush if left on the plant to thoroughly ripen. They need to be harvested mature but not yet ripe as indicated by some fruits dropping, a slight change in skin color, and readiness of the fruit stem to part from the branch. Fruits brought indoors to finish ripening are ready to eat when the flesh at the stem end gives with slight finger pressure.

Still, it takes a certain je ne sais quoi. And again, I’m adept at timely harvest of those varieties I’ve grown the longest and of which I have the most.


One reason pears and kiwifruits can ripen to perfection after harvest is because they are climacteric fruits, which undergo a burst of respiration and ethylene (a plant hormone) production as ripening begins. Some of these fruits, which also which include banana, apple, tomato, and avocado can, if sufficiently mature, ripen following harvest. Soon after their climacteric peak, these fruits start their decline.

Citrus, fig, strawberry, plum, and raspberry are examples of non-climacteric fruits, whose ripening proceeds more calmly. Non-climacteric fruits will not ripen at all after they’ve been harvested. They might soften and sweeten as complex carbohydrates break down into simple sugars, but such changes are indicative of incipient rot rather than ripening or flavor enhancement.

For more about flavor, ripening, and climacteric, see my latest book The Ever Curious Gardener: Using a Little Natural Science for a Much Better Garden.

Picked At Peak Of Perfection

Tomatoes Vs. Sweet Corn

Some gardeners sit tapping their fingers waiting for the first tomato of the season to finally ripen. I don’t. I’m waiting to sink my teeth into my first-picked ear of sweet corn.

Not that my tomatoes don’t taste really good, but they’re also good all winter dried or canned, as is or as sauce. Or just frozen.

An ear of sweet corn, though, captures the essence of summer. Not just for flavor and texture. It’s the whole ritual of peeling back the husks and snapping them off at their bases, brushing away the silk before steaming the ears, and then, holding an ear at each end, biting off kernels from one end to the other like an old fashioned typewriter carriage. (An image perhaps unknown to readers below a certain age.)

An art to harvesting corn at the just-ripe stage, and anxiousness for that first taste, make harvesting, especially early in the season rather tenuous. I do early planning for that first taste by counting the days-to-maturity from when I planted. Problem is that the days listed on seed packets vary: One seed company lists days to maturity for Golden Bantam, the variety I grow, at 75 days; another lists it at 85 days; another at 78 days; and yet another, more realistically, at 70 to 85 days. It depends on where the variety is grown and how the season develops.

The real countdown begins when tassels first appear atop the stalks. Harvest will be about 3 weeks hence.

Then it’s time to keep an eye out for drying tassels at the end of an ear. Once that happens, the time is near. That right moment is critical because harvested too soon, and the kernels have little taste. And this is among those fruits — yes, corn is a fruit, botanically — that will not ripen at all following harvest. Harvested too late, and the kernels are tough and starchy.

That exact right moment for harvest is when the ear feels “full” when grasped in my hand and a kernel on the peeled-back husk, with the ear still attached to the stalk, oozes a milky fluid when pressed with the thumbnail. If all these systems are go, it’s time to snap off the ear and whisk it to the waiting pot of steaming water.Corn, testing for ripeness
Golden Bantam is a non-hybrid variety. Like other non-hybrids, a planting does not ripen all at once, which is not a good commercial characteristic. It’s fine for me, though, because between staggered plantings and a wide window for harvest for each planting, I intend to be eating Golden Bantam corn, a favorite for many gardeners since its introduction in 1906, for weeks to come.

Watermelon, Are You Ripe

Besides the first harvest of Golden Bantam, which I’ll be enjoying by the time you read this, I’m also eagerly awaiting the first harvest of watermelon, which, according to days-to-maturity listed on the seed packet, 65-75 days, I should have already been eating. (I sowed seeds indoors in pots in mid-May but it’s been a relatively cool growing season.)

While I’m confident in harvesting sweet corn at just the right moment, not so for harvesting watermelon, another fruit that will not ripen at all once harvested. Yes, I know all the published indicators of ripeness: drying up of the tendril closest where the fruit is attached to the vine; a dull thud, rather than a tighter, ringing or hollow sound, when rapped with my knuckles; and a yellow or cream-color of the fruit where it rests against the ground, and a toughening of the skin there, enough to resist indentation with a thumbnail. (The thumbnail is evidently a useful harvest tool.)

A ripe watermelon?

A ripe watermelon?

Still, I’m not confident about harvesting watermelons on time, and not even just the first ones to ripen. The trial and tribulation is worth it. I hope to be harvesting and eating ripe watermelon also by the time you read this. (Update: I did and it was.)

Tomatoes, You Are Ripe

In contrast to harvesting Golden Bantam corn and watermelon (I grow the variety Blacktail Mountain), tomatoes are cinch to harvest. Except for some green-ripe varieties, which I don’t grow, tomatoes turn their characteristic shade of red when ripe.

Tomatoes can even be harvested underripe to ripen off the vine. Research has shown that when a tomato is about half green and half pinkish-red on the vine, a layer of cells form across the stem of the tomato sealing it off from the main vine. Then nothing that can move from the plant into the fruit, so the fruit can ripen to perfection.Ripe tomatoes

I came across some older research (J. Amer. Hort. Soc. 102:724-731. 1977) showing that the best-tasting tomatoes are those thoroughly vine-ripened. Duh. I knew that, and will harvest only vine-ripened tomatoes.