The proper time to harvest some vegetable crops is fairly easy to determine. Tomatoes turn red when ripe. Onions are harvested when the tops fall over and begin to dry. While some vegetables exhibit clear signs, the proper time to harvest other crops may require a little more knowledge and experience.
Guidelines for harvesting and storing various vine crops are presented below.
The maturity of vine crops can be approximated by counting the days after flowering. It takes approximately 40 to 50 days for muskmelons and 50 to 60 days for large-fruited watermelons to mature after pollination. Acorn squash requires 55 to 60 days, butternut squash 60 to 70 days, and hubbard squash 80 to 90 days. These figures are based on warm weather. Cool weather will slow growth and delay maturity.
Harvest when the underside or "belly" of the melon turns from a greenish white to buttery yellow or cream. This color change is especially pronounced on the dark green-skinned varieties. It is often less noticeable on lighter-skinned watermelons. In addition, the fruit tends to lose its slick appearance on top and becomes dull when ripe.
The browning of the pig's tail (light green, curly tendril attached to the vine near the melon) is another option for determining ripeness but not always reliable. In some varieties, the pig's tail may turn brown 7 to 10 days before the melon is ripe. Varieties that this can be reliable for include Crimson Sweet, Cathay Belle, Starlight, New Orchid, Sureness, Sugar Baby, and Yellow Doll. Pay careful attention to the pigtail when harvesting to learn if this can be a helpful indicator on other varieties Often the browning of the pig tail can be used in conjunction with the change in belly color to determine ripeness, especially for those varieties whose belly color change is not easily seen.
Some experienced home gardeners may be able to determine the maturity of watermelons using the “thump test”, however, most individuals will have difficulty differentiating between the sounds. Rapping an immature melon with your knuckles produces a metallic ring. A ripe melon gives off a hollow or dull ring. For most individuals, thumping or tapping the melon is generally not a good indicator of ripeness.
When harvesting watermelons, leave 2 inches of the stem on the fruit. Watermelons can be stored at room temperature for about one week. The storage period can be extended to two to three weeks at 40° to 50° F.
Learn more about growing watermelon in this publication: Melons.
The fruit of muskmelon or cantaloupe are mature when the stem pulls (slips) easily from the melon. The melon is not ripe if the stem has to be forcibly separated from the fruit. Other indicators of maturity are based on touch, appearance, and aroma. The flower end (the end opposite the stem) of the melon should be slightly soft. The skin between the netting turns from green to yellow. Finally, a ripe melon produces a strong “muskmelon” aroma, though often the fruit will slip off the vine before the melon is sufficiently lifted to one's nose to sniff!
Muskmelons can be stored in the refrigerator for up to two weeks. The optimum storage temperature is 36° to 45° F. Before refrigerating, place melons in a plastic bag to prevent the muskmelon aroma from flavoring other stored foods.
Learn more about growing melons in this publication: Melons.
Unlike muskmelons, the fruit of honeydews do not slip off the vine when mature. Indicators of ripeness are a change in color of the honeydew from pale green to yellowish-white, a slight softening of the blossom end of the fruit, and the development of a light, pleasant aroma.
Honeydews can be stored for 2 to 3 weeks at a temperature of 50° F.
Learn more about growing melons in this publication: Melons.
Mature winter squash have very hard skins that can't be punctured with the thumbnail. Additionally, mature winter squash have dull-looking surfaces. When harvesting fruit, leave a 1-inch stem on winter squash. Fruit with no stem remaining will not store well.
After harvesting, cure winter squash (except for the acorn types) at a temperature of 80° to 85°F and a relative humidity of 80 to 85%. Curing helps to harden the squash skins and heal any cuts and scratches. Do not cure acorn squash. The high temperature and relative humidity during the curing process actually reduce acorn squash's quality and storage life.
After curing, store winter squash in a cool, dry, well-ventilated location. Storage temperatures should be 50° to 55°F. Do not store squash near apples, pears, or other ripening fruit. Ripening fruit release ethylene gas which shortens the storage life of squash.
When properly cured and stored, the storage lives of acorn, butternut, and hubbard squash are approximately 5 to 8 weeks, 2 to 3 months, and 5 to 6 months, respectively.
Learn more about growing winter squash in this article: Growing Squash in Iowa.
Harvest spaghetti squash when the fruit color changes from ivory white to golden yellow. When harvesting, leave a portion of the stem attached to the fruit. Store mature fruit on shelves in a cool, dry location.
Harvest long-fruited summer squash varieties when they are about 2 inches in diameter and 6 to 12 inches long. Scalloped types are best when 3 to 5 inches in diameter. Fruit should have soft skins (rinds) that are easy to puncture with a fingernail. Seeds should be soft and edible.
Store fresh summer squash in the refrigerator crisper in plastic storage bags or rigid containers to retain moisture. Stored in this manner, squash will maintain quality for 5-7 days. Summer squash can also be frozen or pickled for longer-term storage.
Learn more about growing summer squash in this article: Growing Squash in Iowa.
Harvest cucumbers every 2 to 3 days and promptly pick the fruits when they reach the desired size. Pickling varieties should be harvested when the fruits are 2 to 4 inches long. Slicing cucumbers should be 6 to 8 inches long and 1 1/2 to 2 inches in diameter but still dark green and firm. Over-mature cucumbers left on the vine inhibit additional fruit set.
Cucumbers can be stored for 10 to 14 days at 50 to 55°F and 90 to 95% relative humidity.
Learn more about growing cucumbers in this article: Growing Cucumbers in the Home Garden.
Harvest pumpkins when uniformly orange. Retain a portion of the stem for the characteristic “handle”, typically as long as possible. .
Pumpkins and winter squash should be cured at 80° to 85° F for a few days prior to storage. Store in single layers at 50° to 55° F.
Learn more about growing pumpkins in this article: All About Pumpkins.
Harvest and store ornamental gourds in the same manner as winter squash.
- Vegetable Harvest Guide
- Vegetable Planting and Harvesting Times
- Planting and Harvesting Times for Garden Vegetables (publication)
- Suggested Vegetable Varieties for the Home Garden (publication)
- Cross-Pollination Between Vine Crops
- Crop Rotation in the Vegetable Garden
- Small Plot Vegetable Gardening (publication)
- Container Vegetable Gardening (publication)