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Summer Squash

Summer squash (also known as vegetable or Italian marrow), is a tender, warm-season vegetable that can be grown throughout the United States anytime during the warm, frost-free season. Summer squash differs from fall and winter squash in that it is selected to be harvested before the rind hardens and the fruit matures. It grows on bush-type plants that do not spread like the plants of fall and winter squash and pumpkin. A few healthy and well-maintained plants produce abundant yields.

Recommended Varieties

Summer squash appears in many different fruit shapes and colors:

Scallop or Patty Pan is round and flattened like a plate with scalloped edges, usually white but sometimes yellow or green.

Constricted neck is thinner at the stem end than the blossom end, classified as either "crookneck" or "straightneck" depending on if the stem end is straight or bent, and is usually yellow.

Cylindrical to club-shaped Italian marrows, such as zucchini, cocozelle and caserta, are usually shades of green, but may be yellow or nearly white.

The varietal selection of summer squash has markedly changed in recent years and the number of varieties offered has greatly expanded as the result of new interest, hybridization and introduction of disease resistance. The number of varieties is staggering. Recommended varieties of summer squash include:

Zucchini (Open Pollinated)

Black Zucchini (best known summer squash; greenish black skin, white flesh)

Black Beauty (slender, with slight ridges, dark black-green)

Cocozelle (dark green overlaid with light green stripes; long, very slender fruit)

Vegetable Marrow White Bush (creamy greenish color, oblong shape)

Zucchini (hybrid)

Aristocrat (All America Selection winner; waxy; medium green)

Chefini (AAS winner; glossy, medium dark green)

Classic (medium green; compact, open bush)

Elite (medium green; lustrous sheen; extra early; open plant)

Embassy (medium green, few spines, high yield)

President (dark green, light green flecks; upright plant)

Spineless Beauty (medium dark green; spineless petioles)

Golden Zucchini (hybrid)

Gold Rush (AAS winner, deep gold color, superior fruit quality, a zucchini not a straightneck)

Yellow Crookneck

Early Yellow Summer Crookneck (classic open-pollinated crookneck; curved neck; warted; heavy yields)

Sundance (hybrid; early; bright yellow, smooth skin)

Yellow Straightneck

Early Prolific Straightneck (standard open-pollinated straightneck, light cream color, attractive straight fruit)

Goldbar (hybrid; golden yellow; upright, open plant)

Scallop

White Bush Scallop (old favorite Patty Pan type, very pale green when immature, very tender)

Peter Pan (hybrid, AAS winner, light green)

Scallopini (hybrid, AAS winner)

Sunburst (hybrid, bright yellow, green spot at the blossom end)

Other

Butter Blossom (an open-pollinated variety selected for its large, firm male blossoms; fruit may be harvested like summer squash, but remove female blossoms for largest supply of male blossoms)

Gourmet Globe (hybrid; globe-shaped; dark green, with light stripes; delicious)

Sun Drops (hybrid, creamy yellow, unique oval shape, may be harvested as baby with blossoms attached).

When to Plant

Plant anytime after the danger of frost has passed, from early spring until midsummer. Some gardeners have two main plantings - one for early summer harvest and another for late summer and fall harvest.

Spacing & Depth

Sow two or three seeds 24 to 36 inches apart for single-plant production, or four or five seeds in hills 48 inches apart. Cover one inch deep. When the plants are 2 to 3 inches tall, thin to one vigorous plant or no more than two or three plants per hill.

Care

Any well-drained garden soil produces excellent yields of summer squash. Certain mulches increase earliness and yields, because the roots are shallow.

Harvesting

Because summer squash develop very rapidly after pollination, they are often picked when they are too large and overmature. They should be harvested when small and tender for best quality. Most elongated varieties are picked when they are 2 inches or less in diameter and 6 to 8 inches long. Patty Pan types are harvested when they are 3 to 4 inches in diameter. Slightly larger fruit may be salvaged by hollowing out and using them for stuffing. These larger fruits may also be grated for baking in breads and other items. Do not allow summer squash to become large, hard and seedy because they sap strength from the plant that could better be used to produce more young fruit. Pick oversized squash with developed seeds and hard skin and throw them away. Go over the plants every 1 or 2 days. Squash grow rapidly; especially in hot weather and are usually ready to pick within 4 to 8 days after flowering.

Although summer squash has both male and female flowers, only the female flowers produce fruits. Because the fruits are harvested when still immature, they bruise and scratch easily. Handle with care and use immediately after picking. Be careful when picking summer squash, as the leafstalks and stems are prickly and can scratch and irritate unprotected hands and arms. Use a sharp knife or pruning shears to harvest and wear gloves if possible. Some gardeners also pick the open male and female blossoms before the fruits develop. Especially the female blossoms, with tiny fruit attached, are a delicacy when dipped in a batter and fried.

Common Problems

Cucumber beetlesattack seedlings, vines and both immature and mature fruits. They can be controlled with a suggested insecticide applied weekly either as a spray or dust. Be alert for an infestation of cucumber beetles in early September because these beetles can damage the mature fruits.

For more information on cucumber beetles, see our feature in the Bug Review.

Squash bugsattack vines as the fruit begin to set and increase in numbers through the late summer, when they can be quite damaging to maturing fruit. They hatch and travel in groups, which seem to travel in herds until they reach maturity. Using the proper insecticide when the numbers of this pest are still small minimizes damage.

For more information on squash bugs, see our feature in the Bug Review.

Questions & Answers

Q. Will summer squash cross with winter squash?

A. Summer squash varieties can cross with one another, with acorn squash and with jack-o'-lantern pumpkins. Cross-pollination is not evident in the current crop, but the seed should not be sown for the following year. Summer squash does not cross with melons or cucumbers.

Selection & Storage

Most people harvest summer squash too late. Like winter squash, summer squash is an edible gourd. Unlike winter squash, it is harvested at the immature stage. Ideally, summer squash should be harvested at 6 to 8 inches in length. Pattypan and scallopini are ready when they measure about 3 to 4 inches in diameter or less. Tiny baby squash are delicious too. Large rock-hard squashes serve a better purpose on the compost heap than in the kitchen.

Cut the squash from the vine using a sharp knife or pruning shears to avoid damaging the plant. Summer squash vines are very prolific, the more harvest the greater the yield. The most important characteristic to remember is that summer squash is best when immature, young and tender.

In this section, summer squash varieties will be limited to zucchini, yellow squash (crooked and straight), pattypan which is also call scalloped and scallopini. Because summer squash is immature, the skin is very thin and susceptible to damage. Handle with care. The average family only needs to plant one or two of each variety. Over planting usually leads to hoards of huge inedible fruit and/or scouring the neighborhood for people to take the surplus.

To store summer squash, harvest small squash and place, unwashed in plastic bags in the crisper drawer of the refrigerator. Wash the squash just before preparation. As with most vegetables, water droplets promote decay during storage. The storage life of summer squash is brief, so use within two to three days.

Squash Blossoms

Squash blossoms are edible flowers, raw or cooked. Both summer and winter squash blossoms can be battered and fried in a little oil for a wonderful taste sensation. Harvest only the male blossoms unless the goal is to reduce production. Male blossoms are easily distinguished from the female blossoms. The stem of the male blossom is thin and trim. The stem of the female blossom is very thick. At the base of the female flower below the petals is a small bulge, which is the developing squash.

Always leave a few male blossoms on the vine for pollination purposes. There are always many more male flowers than female. Harvest only the male squash blossoms unless you are trying to reduce production. The female blossom can be harvested with a tiny squash growing at the end and used in recipes along with full blossoms. Use the blossom of any variety of summer or winter squash in your favorite squash blossom recipe.

Use pruning shears or a sharp knife to cut squash blossoms at midday when the petals are open, leaving one inch of stem. Gently rinse in a pan of cool water and store in ice water in the refrigerator until ready to use. The flowers can be stored for a few hours or up to 1 or 2 days. If you've never eaten squash blossoms, you are in for a treat. A recipe for Stuffed Squash Blossoms is in the recipe portion of this section.

Nutritional Value & Health Benefits

Because summer squash is immature, they are considerably lower in nutritional value than their winter counterparts. Generally, there is little variation in nutritional value between varieties. The peel is where many of the nutrients hide, so never peel summer squash.

Nutrition Facts (1 cup sliced, raw zucchini)

Calories 16
Protein 1.31 grams
Carbohydrates 3.27 grams
Dietary Fiber 1.36 grams
Calcium 16.95
Potassium 280.24
Vitamin A 384 IU
Folate 24.93 mcg

Preparation & Serving

Summer squash can be grilled, steamed, boiled, sauteed, fried or used in stir fry recipes. They mix well with onions, tomatoes and okra in vegetable medleys. Summer squash can be used interchangeably in most recipes. Tiny baby squash can be used as appetizers, or left whole and sauteed with other vegetables.

Don't waste male squash blossoms by leaving them in the garden. If you do not have the time or inclination to prepare them separately, toss them in the salad bowl or add to any squash preparation.

Home Preservation

Canning is not recommended because the tender summer squash will simply turn to mush during processing, unless you are making pickles. Zucchini can be substituted for cucumbers in some pickle recipes. The results are especially good in your favorite recipes for Bread and Butter Pickles.

Blanch and freeze cubes or slices of summer squash or grate and freeze Zucchini, unblanched for making Zucchini bread. The best way to use over grown (10 to 12 inches) zucchini is to grate it and use in zucchini bread. Cut the squash in half lengthwise and cut away the seedy middle section. Wash, grate and freeze in one cup portions. Use zip closure freezer bags or rigid freezer containers leaving 1/2 inch head space. Over size zucchini can also be used to make canned zucchini chutney. The over 12-inch monsters should go on the compost heap.

Recipes

Herbs and spices that enhance the flavor of summer squash include marjoram, cumin seeds, parsley, dill, rosemary and savory. Too many herbs and spices mask the delicate flavor of summer squash so use herbs and spices sparingly. Since so many requests come in for recipes for summer squash, several are included in this section.

Zucchini Carrot Bread

To use frozen grated zucchini in bread, thaw the package in a pan of cold water, squeeze out excess water and precede with the recipe. Omit the carrot and substitute 1/2 cup zucchini or other squash, if desired.

1 1/2 cups all-purpose flour
1 cup sugar
2 teaspoons baking powder
1/2 teaspoon baking soda
1/4 teaspoon salt
1/4 teaspoon ground ginger
1 egg, lightly beaten
1/2 cup canola oil
1 cups grated zucchini
1/2 cup grated carrots
1/2 cup chopped walnuts or pecans
Powdered Sugar (optional)

  1. In a large mixing bowl stir together flour, sugar, baking powder, baking soda, salt, and ginger. Set aside.

  2. In a medium bowl, beat the egg, add the oil, grated zucchini, and grated carrots. Mix well.

  3. Add the zucchini mixture and nuts to the flour mixture. Stir only until all the flour is incorporated. Do not over mix or the bread will be dry and chewy.

  4. Scrape the batter into a well greased 9-inch bread pan and bake in a preheated 375° oven for 50 minutes.

  5. Remove from the oven and let the bread cool in the pan 5 minutes, then turn out onto a rack or plate. Serve warm or cool and dust with powdered sugar. Makes one 9-inch loaf.

Summer Garden Vegetable Medley

This recipe includes many of the vegetables found in your garden. Substitute yellow squash for zucchini or a combination of both. Add carrots, or eggplant or whatever you have in the garden.

3 medium zucchini (7 to 8 inches) or 5 small (4 to 5 inches)
1 tablespoon olive oil
1 bell pepper or any pepper variety, seeded & cut into strips
6 trimmed, thinly sliced green onions with tops included
2 cloves garlic, chopped
2 medium tomatoes, chopped
1 teaspoon toasted cumin seeds, ground
1 teaspoon salt
1/2 teaspoon freshly ground black pepper

  1. Wash and thinly slice squash and set aside. Prepare all other vegetables and set aside.

  2. To toast cumin seeds. Heat a heavy skillet over low heat. Add the cumin seeds and shake the skillet periodically. When their aroma begins to be noticed, after about 5 minutes, remove the skillet from the heat. Pour seeds into a mortar, allow to cool then grind. Or use a spice grinder.

  3. Heat a non-stick skillet or wok over medium heat. Add oil. When oil is very hot, add peppers, onions and garlic. Cook for 2 minutes, stirring constantly. Add zucchini and tomatoes and continue cooking for 5 minutes.

  4. Sprinkle with ground cumin, salt and pepper, stir. Serve hot or cold. Makes 6 servings.

Spicy Squash Cakes

This recipe works well with a combination of zucchini and pattypan or yellow squash. Temper the fieriness of the jalapenos by adjusting the amount or by removing the seeds and white membrane. Prepare small cakes for an appetizer or larger ones as a side dish or serve with crusty bread and tomato salsa for a full meal. The salsa recipe is in the section on tomatoes.

1 whole egg plus 2 egg whites or use 3 eggs
4 cups grated summer squash
1 cup fresh corn kernels, cut from 2 ears
1/4 cup chopped green onions, tops included
1 large jalapeno pepper, chopped
1/3 cup parmesan cheese
1/2 cup grated sharp cheddar cheese
1/2 cup all-purpose flour
2 tablespoons olive oil
1 teaspoon ground cayenne pepper or black pepper
Canola oil for sauteing
Low-fat sour cream (optional)
Fresh tomato salsa (optional)

  1. In a large bowl, beat the eggs. Beat in squash, corn, green onions, jalapeno, the cheeses, flour, olive oil and ground pepper.

  2. Heat two tablespoons canola oil in a heavy 10-inch skillet over medium-high heat. For small cakes, spoon one tablespoon squash mixture per cake into the hot oil and flatten to uniform thickness. For large cakes, use two tablespoons of squash mixture per cake. Do not over crowd the skillet. Leave about an inch between cakes.

  3. Cook until edges turn golden brown, turn and cook the other side until golden brown, about three minutes total cooking time per cake. Transfer to a paper towel lined plate. Place in a warm oven and continue cooking the remaining cakes.

  4. To serve, arrange two or more cakes on individual plates. Serve with some of the salsa and a dollop of low-fat sour cream. Sprinkle with salt if desired. Serves 6.

Stuffed Squash Blossoms

Read the section on "Squash Blossoms" before you go charging out to the garden. Use your favorite bread or meat stuffing or use the ricotta/mushroom stuffing below. Or skip the stuffing, and simply batter the blossoms and fry. The batter must be chilled for 30 minutes. Or it can be made in advance and refrigerate it for up to two days. If it is too thick after refrigeration, add a few drops of water to return to original consistency.

The Batter

1 cup flour
1/2 cup cornstarch
1/2 teaspoon salt
1 cup fat-free chilled milk, beer or water

The Stuffing

1/4 cup ricotta cheese
1 garlic clove, minced or pressed
1/4 teaspoon each salt and pepper
2 tablespoon mushrooms, finely chopped
1 tablespoons fresh basil or parsley, minced
16 large squash blossoms, washed
Canola oil for frying

  1. Prepare the batter first. Sift together dry ingredients, then whisk in milk, beer or cold water until smooth. Cover and set in the refrigerator for 30 minutes. Leftover batter can be stored for up to two days.

  2. Meanwhile, prepare the stuffing. In a bowl combine the ricotta cheese, garlic, salt, pepper, mushrooms and basil. Open the blossoms and spoon about one 1/2 teaspoon of the mixture into the center of each. Avoid overfilling the blossoms. Twist the top of each blossom together to close. Place on a baking sheet and refrigerate for 15 minutes.

  3. Pour the oil into a skillet to a depth of 1/2 inch. Heat over high heat until a small cube of bread dropped into the oil turns golden brown within seconds.

  4. Briefly dip each stuffed blossom into the batter, then carefully slip into the hot oil. Cook until golden on all sides, about three minutes total cooking time. Add only as many blossoms at a time as will fit comfortably in the skillet. Transfer with a slotted utensil to paper towels to drain briefly.

  5. Sprinkle with salt, if desired and serve immediately. Serves 4.