Harvesting fall squash

I've received several questions about when fall squash are ready for harvest. Fall or winter squash should be harvested when fully mature which is more typically in September than August. Immature fruit have a watery flesh, don't store well and if harvested are eaten like summer squash. Not all of them will taste good when eaten immature, hubbard and golden acorn reputedly are O.K.

As fall squash matures, the flesh becomes drier and sugars develop. Both changes contribute to storing quality. Some types will store up to 3 or 4 months when harvested at the right time and stored under ideal conditions (dry and 55 degrees F). One inch of neck should be left on the fruit and it should be hard and dry when harvested.

General signs of maturity are skin that can't be easily dented with a thumbnail, color that is true to mature type, and reaching the proper number of days to harvest.

Certain types of squash have other things to look for. On acorns, the groundspot where fruit touches the ground will change from yellow to orange. Carefully turn fruit over to check being careful not to detach from the stem in case you have to roll it back to let it ripen further (photo acorn above left - still yellow: immature). On golden acorns, the groundspot doesn't show like it does on green acorns. Yellow skin should turn a deep golden yellow at maturity on these.

Butternut squash are ripe when vine growth stops and skin color changes from a light whitish tan to a deep tan (photos below - left photo immature, photo right fruit medium mature and still needs time to turn a deep tan).










Vegetable spaghetti squash are mature when they turn from a light yellow to golden yellow (photos below). Buttercup squash are ripe when dark green fruit are 5 to 6 inches across and stop growth. These are the most common varieties grown by home gardeners because their approximately 80 to 85 days to harvest makes them reliable in our climate.











Blue hubbard (blue-gray) and Boston marrow (reddish-orange) are occasionally grown. They take a full season, 110 and 120 days respectively, and are mature when vines die down.


Photo credit: Rotating acorn to check maturity, Butternut immature and medium mature, Vegetable spaghetti immature and mature - All Carl Wilson

Squash viruses

Several viruses affect squash including squash mosaic virus and cucumber mosaic virus. Aphids transmit the viruses from infected plants that can include weeds such as common lambsquarters, kochia and others.

You may discover viruses as we did recently in our yellow zucchini planting by spotting one plant with light green, mottled leaves in a sea of healthy. dark green leafed plants. (Click photo to enlarge). Leaves often have a mosaic pattern and may be distorted, have deep lobes, or appear string like and thin.











Fruit can appear small, deformed, mottled, have ring spots or exhibit color breaks and may develop warts. In our planting the affected fruit (photo left) look quite different than normal yellow zucchini (photo right). The different viruses produce different symptoms depending on the stage in which the plant is affected and several viruses can affect the same plant.

Do plant virus resistant or tolerant varieties when available. Purchase seed from a reputable supplier and use care in saving seed. Manage aphids to keep numbers low. As soon as diseases appears, remove plants like we did. Viruses can be mechanically transmitted so wash hands and tools before working with healthy plants. Control nearby weeds that may harbor viruses. There are no pesticides to control viruses.

Photo credit: Virus mottled leaf plant stands out, Virus distorted fruit, Normal yellow zucchini fruit - all Carl Wilson

Tomato pruning debate

I've had several conversations about removing tomato suckers with people recently. Suckers for those who don't know are the shoots that grow between the tomato leaf branch and the main stem. If you choose to remove them, do so when they are young rather than letting a large shoot develop. The question is should you remove suckers or not?

There certainly are some pluses to this growing technique: easier to train on a support whether stake or cage, ability to plant more plants closer together and easier access to harvest fruit. See photo of tomato in a pot with slim form produced by having all suckers removed. The alternative is not pruning which usually is done by letting tomatoes run on the ground. With large, 3 to 4 feet wide, sturdy cages, not pruning is also often practiced.

One of the disadvantages of removing suckers is exposing fruit by having less leaf cover. This can increase the chances of sunscald (photo). Sucker removal carried to the extreme probably limits the photosynthetic capacity of the plant particularly with some less robust tomato varieties.

You also can use some of both techniques along the way. Removing suckers at first and then slacking off and letting them grow later produces more leaf cover to protect fruit from sunscald. What works for you?

Whether you are pruning or not, you should have fruit beginning to ripen. Nighttime temperatures are already beginning to drop into the fifties along the Front Range. The August transition to fall will also see more daytime temperatures in the eighties. For warm weather loving tomatoes, fruit development should be well along at this point in the growing season.

Photo credit: Tomato plant with suckers removed, Sunscald on green tomato fruit - both Carl Wilson

Seed or transplant for Fall

Now is the time to finish seeding or transplanting 50 to 60 day crops to mature in Fall. We just finished installing kale, red and golden beet transplants (photos). Even though it's hot now, these crops and others including lettuce will grow and be of good quality as they mature in cooler fall temperatures.

Planting a second crop where spring crops leave "vacancies" increase yields from a given square footage of soil during a growing season. Rotate crops and don't plant same family plants such as kale following cabbage. We planted beets following lettuce and cabbage, and kale following beets.

This higher demand on garden soil is equivalent of a full season crop such as tomato or potato. It requires adequate organic matter and fertility to meet the needs of the second crop so do be sure your soil is prepared to handle succession planting.

Photo credit: Transplanted kale, red beet, golden beet - all Carl Wilson

Hail recovery hope

To encourage those with gardens struck by hail, this post features pictures from a previous year's hailstorm. While chances of recovery depend on the extent of the damage, plants can surprise. Fruiting vegetables always seem to sustain the worst damage, particularly the big-leafed vegetables like squash and pumpkins. Roots escape underground and regrow. Leafy vegetables generally come back.

These photos of tomatoes and straightneck summer squash are from a July 21 hailstorm. White hailstones are visible in tomato photo. Click on photos to see enlarged view.



The photos below show plants August 17, about a month later. The Yellow Taxi tomato is sparse and shows hail-nicked foliage but did ripen fruit. The summer squash put on an amazing amount of growth and more fruit.

Photo credit: All five photos in post - Carl Wilson

Use of Mid-summer Transplants

While many people think of transplants as only a May start-of-season planting technique, they can also be useful in midsummer for planting crops for fall harvest. In midsummer you don't even need a greenhouse to grow them!

There are always two ways to plant - direct seed or transplants. Mid-July is a rough date to have 50 to 60 day vegetables direct seeded to mature for fall. Using this target date, you can plan whether transplants or direct seeding will best work in your crop scheduling following spring crops.

Perhaps you have a crop growing that won't be harvested in the end of July and direct seeding another would not allow it to mature before frost. Answer is grow transplants. Or perhaps you have difficulties directly seeding the garden because of wind and sun, soil crusting or other physical soil condition, inability to frequently water to germinate seed, garden pests on young seedlings or whatever reason. Transplants may work better for you.

Growing transplants in pots placed on the ground (or bark mulch) as pictured works well. Floating row cover fabric thrown over the pots and tucked under the trays conserves water and helps seeds to germinate. Remove when seedlings have begun to develop true leaves or leave on to protect from birds and insects. Grow for 4 weeks or so and you are ready to gain a jump on the fall harvest season by transplanting into your growing beds.

Photo credit: Trays of pots growing on bark mulch, Kale (bottom) and beets (top) grown as midsummer transplants - both Carl Wilson