Tomatoes are among the vegetables that thrive in early Louisiana gardens. (Photo by Dan Gill)

For Release On Or After 06/06/14

By Dan Gill
LSU AgCenter Horticulturist

June is the peak month for harvesting early-summer vegetables. One reason people grow their own vegetables is for the outstanding quality of freshly harvested produce. Harvesting at the right stage, however, is essential to getting the best quality vegetables from your garden.

It’s important to understand that some vegetables are harvested while still immature, including eggplants, summer squash, cucumbers, okra and snap beans. Do not leave these vegetables on the plant too long, or quality will quickly decline.

Other crops, such as tomatoes, winter squash, bulbing onions, garlic and sweet corn, are harvested when ripe. For best quality, they must be left on the plant until fully mature (or fully developed in the case of onion and garlic bulbs).

Peppers are unique in that they can be harvested in the immature, green stage (typical for bell peppers and jalapeno peppers), when fully ripe (generally red) or at any stage in between.

You can enjoy the best quality if the vegetables are consumed soon after harvest. If you can’t consume them immediately, you can preserve the quality of most vegetables by refrigerating them as soon as possible to slow down respiration and water loss. Exceptions are Irish potatoes, tomatoes, melons, garlic and onions, which should be stored at room temperature, although tomatoes and melons can be chilled prior to serving.

Most vegetables should be used within five days for best quality and nutritional content.

Harvesting tips

Snap beans should be harvested when pods are about the diameter of a pencil and bean seeds are very small. If bean pods are allowed to mature on the plants, the beans can be shelled and cooked as shelled beans.

Harvest sweet corn when the silks turn light brown to brown. You can peel back the shuck to see how developed the kernels are before removing the ear. The juice of the kernel should be milky when you puncture it with your thumbnail. If the juice is clear, it is not ready. Sweet corn should be eaten as soon as possible after harvesting for maximum sweetness.

The mature size of cucumbers varies with variety; however, harvesting should be done before the cucumber begins to lose its green color. Old cucumbers will begin to yellow, have well-developed seeds and become bitter.

Eggplants should be harvested when they are one-third to two-thirds of their full, mature size. The skin should be glossy. Dull skin indicates over-maturity, and the fruit will be seedy and often bitter. Harvest using pruning shears because the stem is tough.

Onions, garlic and shallots should be dug when the leaves are half-dead and the tops are falling over. Harvest on a sunny day and allow the plants to remain in the sun for at least one day. Remove the roots from the base, and cut the stem about 1 inch above the bulb. Store in a cool, dry place.

Irish potatoes are generally harvested from late May through early June. Potatoes should be dug when at least 50 percent of the foliage has died. Cut the plant off near ground level, but let the potatoes remain covered in the soil three to five days before digging.

Peppers, both sweet and hot, can be harvested at any size or color. Nearly all peppers will turn red at maturity, though some turn orange or yellow, but may be green, purple, yellow or orange along the way.

Tomatoes can be harvested any time after green fruit begins to turn pink. If you harvest early, often to get the fruit out of harm’s way from birds and insects, you can ripen the fruit at room temperature and still expect excellent quality. Light is not needed for ripening, so there is no need to put them in a window. Best quality, however, comes when fruits fully ripen on the plant.

Okra should be harvested every two to three days. Most types should be harvested when they are young, tender and less than 3 inches long. The pod snaps easily from the plant when they’re harvested at the proper stage.

Summer squash, including zucchini, should be harvested small and immature while the skin is still tender – one-half to two-thirds the mature size. The more frequent the harvest, the more fruit the plant will produce. Use a knife to remove the fruit, leaving 1 inch of stem attached.

Winter squash should develop a tough skin before harvesting. When they are ready to harvest, you cannot puncture the rind with your thumbnail. If too immature, the squash will be low in sugar and have a bland flavor.

Harvest the pods of Southern peas – purple hull, black-eyed and others – when they are well filled and have changed to a light straw, silver or purple color, depending on the variety, because they shell easiest at this stage. Ideally, shell out and use the peas the day they are harvested. Shelled peas may be stored in a covered bowl in the refrigerator for several days prior to cooking.