Acorn squash (Cucurbita pepo var. turbinata) is ready for harvest in fall when its fruits are ripe. Mature acorn squash fruits can store for five to eight weeks in the right conditions, and several signs show the fruits are mature. Acorn squash is an annual vine plant that produces round, green or gold fruits with pronounced ribs.
Weeks from Sowing
Start checking an acorn squash's fruits for signs of ripeness about 11 weeks after sowing. The fruits usually mature about 80 to 100 days after the plant's seed was sown. If you didn't grow the acorn squash from seed but planted a container-grown plant, then check the vine about eight weeks after planting. An acorn squash seedling is ready for planting when it is about 3 weeks old.
If you aren't sure how long the acorn squash plant has been growing, then check its leaves and stems. When the plant's fruits ripen, the leaves and stems turn yellow and wither.
Signs of Maturity
Acorn squash fruits' skins change as the fruits mature. One sign to check for is dullness. Immature fruits are shiny, but the shine disappears as the fruits ripen. Another sign to check for is an orange patch where each fruit touches the ground.
Turn an acorn squash fruit carefully to check for the orange patch. Turning the fruit too roughly can break the stem that attaches the fruit to the plant.
Tough skin also indicates maturity in an acorn squash fruit. Try to make a mark in the skin with your thumbnail. If you can't, the fruit is ripe.
If a hard frost is forecast, harvest your acorn squash fruits. They can withstand light frost, which improves their flavor, but prolonged freezing temperatures damage their flesh.
Tips for Harvest
When harvesting acorn squash fruits, leave the stem tips attached to the fruits, and do not cure the fruits. Cut the stems 1 inch from the fruits with pruning shears.
Sterilize pruning shears before and after harvesting acorn squash by wiping the blades with a cloth soaked with rubbing alcohol.
Acorn Squash Storage
Storing acorn squash fruits in a cool, dry, dark place prolongs their storage life. Place the fruits on wooden pallets, and stand the pallets on blocks to allow air to circulate around the fruits.
Don't allow acorn squash fruits to touch during storage. Rot can spread through their contact.
The best conditions for storing acorn squash fruits are a temperature of about 50 degrees Fahrenheit and 50 to 75 percent humidity.
Check the stored fruits every week for signs of decay, and discard decaying fruits.