Summer harvesting tips: When to pick tomatoes, corn and beans

Prime-time harvest-helping tips

We vegetable gardeners are in our glory now, with the crops of summer ripening up rapidly. So it’s time for tips on what to pick promptly and what to let sit a spell.

Pick your tomatoes promptly

Pick tomatoes on the same day they achieve full ripeness. Once a tomato is dead ripe, it begins to lose flavor if left outdoors in the sun — especially on a hot day.

In fact, it’s smarter to pick tomatoes when they’re about halfway colored-up. They’ll reach peak flavor if you just bring them inside and sit them out in the open in your kitchen. (But not in any kind of direct sun; that’s what you just saved them from!) Don’t put them in the refrigerator either; cold makes them mealy.

Picking tomatoes at what’s called the breaker stage also induces new flowers to form. And, perhaps most importantly, it prevents pests like hungry hornworms, smarmy stink bugs, slimy slugs, pecking birds and Evil Squirrels from ruining your perfect tomato at the last minute.

Sweet corn: It’s time to check your ears

Growing your own sweet corn is a lot easier than many people think. You don’t need to grow a full field to get good pollination. Home gardeners, you can get nice, big, full ears from a patch of around 36 plants. Plant them in a block, not a row, so that most of the pollen grains fall into developing silks. (Each grain of pollen that falls into a silk becomes a kernel in the finished ear. How cool is that?)

And those silks also offer one of the best clues to help deduce if your crop is ripe, sweet and ready to eat, which is generally about three weeks after those silks become visible. When we get to that window (and/or reach the “days to maturity” number on your seed packet label), choose a nice fat ear with silk that is at least a little brown and gently peel back the tips of the leaves until you expose the first couple rows of kernels. (Don’t pull the ear off the plant just yet.)

Pierce a few kernels in the third row from the top with your fingernail; if the liquid is white and milky, break out the butter and salt! Just wait to actually harvest until the water is boiling or the grill is hot. Sweet corn begins to lose its sugar as soon as you pull it off the plant.

If you have to harvest before you’re ready to eat, put the picked ears into the fridge or a cooler filled with ice packs immediately. And harvest early in the morning whenever possible — that’s when the sugars are most highly concentrated.

(Oh, and if it’s not ready yet, pull the leaves back over the tested area and tape it shut. Really!)

Pick these plants early and often

It’s harvest time in the truck patch! And one way to maximize both the flavor and quantity of some produce is to pick it while it’s still really, really small.

Both summer and winter squash, for instance, are edible at any stage. In fact, the smallest baby squash are the sweetest. And picking when small will keep the plant pumping out more flowers that will turn into more squash. And those squash blossoms are also edible on their own (try them stuffed with a flavored soft cheese. Yum!).

Same goes for “beans for fresh eating.” (As opposed to beans grown for drying and winter storage, like kidney beans.)

Depending on where you grew up, you might call these fresh-eating types of beans string beans, snap beans or green beans. And the varieties you chose to grow back at the start of the season might be compact and down-low, bush style plants or the kind of “pole beans” that require a really tall trellis.

Doesn’t matter. They all taste best when picked small and slender — ideally before you can even see the bulge of any seeds inside.

This early picking will signal the plant to keep flowering and pumping out fresh pods. Baby beans have the highest possible sugar content and best flavor. And because they’re so young they won’t yet have developed the strings that give them one of their common names.

(Oh — and if you are growing beans for drying, the opposite is true. Leave them on the vine until the pods are crispy dry brown to make sure they’re fully mature.)

There are no green peppers

You know what drives me crazy? People who tell me that they’re growing “green peppers.” What’s so wrong with that? There technically are no green peppers!

There are several popular (and tasty) varieties of tomato that are green when they’re ripe (Green Zebra is a farmers market favorite). But every single kind of pepper — hot or sweet — will ripen to a color other than green.

With sweet peppers (which you might call bell peppers, referring to the most common shape) the final color will either be yellow, orange, red or a beautiful chocolate hue, (sorry, you only get the chocolate color, not the flavor) or sometimes with a dramatic purple stage in between. That’s right, the purple peppers you see in the market were once green, and if left on the plant would eventually turn red.

So be patient — that change in color not only turns the bitter starches of green peppers to sweet sugars, but more than doubles the amount of vitamin C and other nutrients that peppers contain. A ripe, red, sweet pepper has about the same amount of vitamin C as a medium-size orange (more than 100 percent of the recommended daily allowance) and delivers an astounding 11 times more of the cancer-fighting compound beta-carotene than a greenie.

You don’t have to sizzle to make tomato sauce

(Or, if you’re from South Philadelphia, red gravy)

Anyway, don’t be alarmed if your tomato plants are covered with big beefsteak-sized fruits that are all still green. The really huge, multi-pound love apples (like Brandywine, mortgage lifter and the like) take a long time to ripen up. This is why I always urge people to plant a few early- and midseason varieties, which are coming in like gangbusters right now.

This provides many of us with the poundage we need to make our own tomato sauce for the winter, but at a time when we really don’t want to have a hot pot simmering on the stove inside for hours.

So if you can, cook your sauce down outside, on a propane-powered camp stove or a gas grill with a side burner. (Or, if you really are from South Philly, in the summer kitchen you likely somehow have even if you live in an apartment.)

Or do it inside, but cut the simmering time down to a fraction (which also preserves nutrients and prevents any bitterness from creeping in) with a clever trick I dreamed up many years ago.

My 60-minute sauce:

Whip up all your ingredients together in a blender to meld the flavors completely up front. My own personal sauce is very simple: tomatoes with the stems and seeds removed (but the skins left on), a good amount of garlic, and lots of either basil or oregano (but not both in the same batch). No added salt, sugar or black pepper. This sauce tastes best unaltered!

Quickly bring the mix to a slow simmer and then use a strainer to separate the thick sauce from the thin juice that will rise to the top of the pot. Keep dumping everything that stays in the strainer into another pot until you only have clear liquid in the first. Then jar them separately and use the juice to make tomato soup on a cold winter’s day!

Mike McGrath was Editor-in-Chief of ORGANIC GARDENING magazine from 1990 through 1997. He has been the host of the nationally syndicated Public Radio show “You Bet Your Garden” since 1998 and Garden Editor for WTOP since 1999. Send him your garden or pest control questions at

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