Cucurbits, which include cucumbers, muskmelons, watermelons, pumpkins, summer squash, winter squash, and gourds, are some of the most popular garden vegetables planted today. Cucurbit crops are similar in their appearance and requirements for growth. They are prostrate, sprawling vines, usually with tendrils. Each vine bears many large, lobed leaves. On all cucurbits, except for the bottle gourd, the flowers are bright yellow. Each vine bears two kinds of flowers: pistillate (female) and staminate (male). Cucurbits are warm season crops which grow best during periods of warm nights and warm days. New dwarf and/or bush types enable gardeners with limited space to enjoy the fresh home grown taste of cucumbers, watermelons, and squash. Although traditional cucurbit types require substantial growing space, they can still be grown in small gardens by training vines onto vertical structures that conserve garden space.
Cucurbits require full sun to grow well and do best on a loose, sandy-type soil, but can be grown successfully on almost any soil if it’s well-drained and properly prepared, you should add a liberal amount of organic matter, which will help loose, droughty soils hold moisture and nutrients, while loosening up and aerating heavy soils. Scatter 2 to 3 inches of well-decomposed leaves, grass clippings, hay or compost such as Lady Bug Natural Brand Revitalizer, Farm style, or Turkey Compost.
Cucurbits require low nitrogen and high potassium and phosphorous for good fruit development. Add a complete fertilizer such as Lady Bug Natural Brand Flower Power or similar analysis at a rate of 1 to 2 tablespoons per hill prior to planting. Ensure an adequate nitrogen supply by side-dressing with Lady Bug Natural Brand 8-2-4 or similar analysis at the rate of 1 tablespoon per hill one week after blossoming begins. Make a second application 3 weeks later. Do not over fertilize with nitrogen as this encourages vine growth and retards fruiting. Bush, dwarf, and short-vine plants do not need as much fertilizer as standard types.
Plant cucurbits after all danger of frost have passed and when the soil has warmed to 60°F. The last spring frost dates will vary in different locations around the state.
Cucurbit seeds require very warm soil to germinate; at least 60°F. Seeds will rot if the temperatures are under 60°F.
To form a hill, mound soil to make a low, broad hill about 8-10 inches high. Plant 4-6 seeds in a circle in 5 inch intervals for each hill. Each hill should be 4-8 feet apart, depending on the variety you select. Plant cucurbit seeds 1 inch deep, add 1 tablespoon of Lady Bug Natural Brand Pachamama Worm Castings. Cover and lightly tamp the soil but not so firmly as to create a crust. Thin when seedlings have 2 or 3 leaves. Remove all but 2-3 large, healthy, well-spaced plants per hill. More than 3 plants per hill will lead to crowding, greater chance of disease, and lower yields.
When purchasing transplants, look for stocky plants free of diseases, pests, and yellow leaves, which are a sign of stress. Transplant cucurbits when plants have developed two adult or “true” leaves.
If you sow seeds to be transplanted outside at a later time, plant 2 seeds per pot. When they are 2 inches tall, thin to one strong plant. Two to three weeks are needed for seedlings to grow to transplant size. Set plants out during the late afternoon or early evening, when the wind has died down, to avoid stress from the hot summer sun. First, make the rows as you would for seed or prepared hills. Then dig a hole for each plant roughly twice as wide and twice as deep as the soil ball. Keep in mind the proper planting distance as noted earlier. Next, set each plant slightly deeper than it grew before; add 1/4 cup of Lady Bug Pachamama Earth Worm Castings, and place soil around the roots. Finish by filling the hole with soil, leaving a small basin around each plant. If the next 2-3 days are sunny, cover the new transplants with newspaper “tents” or shade cloth to prevent wilting. Water as needed and water thoroughly each time.
Cucurbits are deeply rooted, so water slowly with 1 inch of water per week. Allow it to completely soak the soil 6-8 inches deep. Water in the morning or early afternoon so the foliage dries by evening. This helps prevent the spread of leaf diseases. Decrease watering later in the season to encourage fruit to mature. At this time, the root systems will be more extensive and able to withstand drier conditions. Furrow irrigation is best, but soaker hoses also work well. Overhead sprinklers can be used although wet foliage increases the chance of disease. Cucurbits will benefit from organic mulches applied in the summer after the soil has warmed.
Insects and Diseases
Some of the most common threats to Cucurbits are Powdery Mildew, which can be controlled with Serenade, vine borers which can be prevented by covering the plants with light weight row cover and hand pollinating, and spraying base of plant with a B.t. solution weekly. Lastly, the dreaded Squash Bug, you can drown ‘em, boil ‘em, mash ‘em, apply D.E., or vacuum with shop vac.
Rotation is the practice of changing the location of vegetable crops in a garden each year. Cucurbits are generally attacked by the same pests so they should be rotated on a 3-year schedule. An example might be to grow muskmelon the first year, then grow tomatoes in the same location the second year, and beans the third year. This can then be repeated. Rotate cucurbits on a 3-year schedule with any vegetable other than those from the cucurbit family.
Insecticides should be used in late afternoon or early evening to avoid injury to pollinating bees.
The first flowers that appear on cucurbits are usually male. Male blossoms do not bear an immature fruit or ovary directly behind the petals as do female flowers. They furnish pollen for bees to pollinate the female flowers, and then drop off the plant naturally without fruit production. The female flowers have an ovary directly behind the flower, which looks like a tiny fruit. When pollinated, it swells to form a fruit. If the female flowers bloom before there are male flowers to supply pollen, they will dry up or produce small fruits that drop off and die. If cucumbers tend to be misshapen, it is due to incomplete pollination. The next fruits will probably be the proper shape.
Muskmelons and Other Melons
The Muskmelon is a popular fruit that is eaten fresh or can be frozen. Muskmelon is frequently called cantaloupe. However, the true cantaloupe has a hard, rough, warty, or scaly rind and is not commercially available. Muskmelons Have orange flesh and a netted rind. Other melons include casaba, honeydew, Christmas and Persian melon. Honeydew fruit is large and mildly scented. The flesh is crisp and white or green in color; the rind is smooth. Casaba is similar, except it has a wrinkled rind. Persian is similar to muskmelon, but the fruit is larger. Christmas melon has lightly colored flesh. The fruit is oblong with green and yellow stripes. To grow muskmelon, choose early cultivars for direct sowing outdoors, or start main and late season cultivars indoors to insure adequate time for melons to ripen. Harvest muskmelon early in the day, after the plants are dry. Be careful not to damage the vines. Pick melons every other day at the start of the season and every day at peak season. At maturity, the stem appears cracked at the point of attachment to the fruit. Check for maturity by gently lifting the melon. If it is ripe it should easily separate from the vine. When ripe, the muskmelon rind changes from green to tan or yellow between the netting. To harvest Casaba and honeydew, cut them off the vine after they turn completely yellow. They will continue to ripen (become soft and mellow) if kept at room temperature for a few days. When they are completely ripe, the blossom end yields to pressure.
Persian melons are ripe when they have a sweet, fruity aroma at the blossom end. If melons are not yet ripe in September and a hard frost is predicted, cover the foliage and immature fruit with newspaper.
Problems—Muskmelons may crack during periods of high humidity which is common during the summers rainy period. Poor flavor and/or smooth rind is due to cool temperatures; wet, cloudy weather; poorly adapted cultivars; poor soil fertility (especially low potassium) and picking the melons before they are ripe.
Choose cucumber cultivars according to their intended use. Slicing cucumbers (6-8 inches), pickling cucumbers
(2-6 inches), burpless cucumbers (6-15) and novelty cultivars are available. For small gardens, use trellis, wire
cages, or bush types. Planting, fertilization, and other problems are similar to other cucurbits. Refer to general information on cucurbits.
Summer squash is available in many different shapes and colors. Popular types include scallop or patty pan types (green or white); crookneck or straight neck (usually yellow with a constricted neck); and Italian marrows (club shaped such as zucchini, cocozell and caserta).
Bush types are available for small gardens. Follow the general planting, fertilization, and care as outlined for cucurbits. Harvest zucchinis when they are 2 inches in diameter or 6-10 inches long. Pick yellow types at 4-7 inches and patty pan or scallop types when they are 3-5 inches in diameter. They are usually ready to pick 4-8 days after flowering.
Winter squash can be stored in a cool dry area for many months. They are available in many shapes, colors, and sizes. Small types (4 pounds) include acorn, butternut, and buttercup. Intermediate (6-12 pounds) and large (15-40 pounds) include banana and hubbard. There are a few bush types for small gardens. Follow the general planting, fertilization, and care as outlined for cucurbits. Harvest winter squash when stems are grayish and starting to shrivel. Spaghetti squash should turn a golden yellow and banana squash a golden orange when ready to harvest. Cold weather increases the sugar content of winter squash; so if a frost is expected, cover the fruit and vines with newspaper or row cover.
Pumpkins are available in several sizes: small (4-6pounds), for cooking and pies; medium (8-15 pounds) and large (15-25 pounds), for cooking and jack-olanterns; and jumbo (50-100 pounds), for showing at fairs and exhibits. There are also naked seeded or hull-less cultivars for roasting seed. Bush and semi-vining cultivars are used for small gardens. Follow the general guidelines for planting and maintenance of cucurbits for growing pumpkins. Pumpkins should be harvested when they have a deep, solid color and the rind is hard. The vines will usually be dying back at this time. Cover during a light frost and avoid leaving pumpkins out during a hard frost to prevent softening.
Watermelon fruit may be large (20-30 pounds), medium (10-15 pounds), or small (5 pounds). In small gardens, use bush types. The larger the fruit the longer the growing season. Follow the general guidelines for cucurbits when growing watermelons. Use a combination of the following four indicators to determine when watermelons are ripe:
- The light green, curly tendrils on the stem near the point of attachment turn brown and dry. Some varieties may do this 5-10 days before the fruit is fully ripe.
- The surface color of the fruit loses its slick appearance and turns dull.
- The skin becomes rough and you can penetrate it with your thumbnail.
- The cultivars that are predominantly dark green will turn a buttery yellow on the ground side. Lighter melons will also turn yellow, but not as deep as darker melons.
The gourds most commonly grown belong to two genera: Cucurbit and a Lagenaria.
The Cucurbit types are the most common, as they are the most colorful and contain unusual shapes. The surface may be smooth or warty, plain or colored, and sometimes ridged, or with stripes. In the C. pepe var. ovifera, there are several shape variations such as the apple, bell, egg, or pear. Colors may be orange or bicolor. The Lagenaria types are commonly called the bottle or dipper gourds. The fruit may be smooth, knobby or ridged. Some are only three inches long, while others may be more than three feet long. Shapes vary from globe, dish, bottle, dumbbell, club, crookneck, or coiled. Planting, fertilizing, and care are similar to other cucurbits. Fruits of gourds are picked for eating about 1 week after flowering. Harvest gourds before frost except for the Luffa or sponge gourd. Luffa should be left on the vines until mature or the vines are killed by frost. To prepare a sponge from the luffa gourds, peel the brown skin from the fibrous interior. It will separate quite readily if the fibrous interior is still moist. After peeling, remove the seeds by shaking, then wash the “sponge” in warm, soapy water. If the fibers are to be whitened, place the sponge in a solution of bleach, rinse, and dry in the sun. It can be used as is or moistened and dried again between papers with weights on top.