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Guide to growing cucumbers, squash, melon (Cucurbits)

Cucurbits are plants from the gourd family Cucurbitaceae and include cucumbers, melons, squashes, and pumpkins.


Selecting your varieties

So many varieties of cucumbers! Bush or vine; slicing or pickling; seedless or not; burpless; English, Persian, Armenian, Asian and lemon. Select varieties that suit your garden space constraints, taste and climate. If you live in a cool-summer climate, consider a variety that is resistant to powdery mildew.

Where, When and How to Plant Your Seedlings:

  • Cucumbers like heat! Choose a warm and sunny spot. Plant 18 inches apart.
  • If your plant is a vining variety, provide it with a supportive trellis when you plant it.

Soil and Fertilizer

Consider adding a low-nitrogen, high potassium/phosphorus fertilizer at planting. While the plant is producing, fertilize with a balanced fertilizer (containing nitrogen, phosphorus and potassium).


Water regularly to keep soil evenly moist. Cucumbers are mostly water, so the plants will need lots of water as the fruit is developing. Mulch with compost or straw to conserve moisture. Mulch will also help reduce pests.


Harvest cucumbers frequently, every one to two days, so that the plant keeps producing. Pick at the recommended size for the variety you chose.


Squash—Summer and Winter

Summer squash include: pattypan, crookneck, zucchini

Winter squash include: pumpkin, butternut, kabocha, delicata and spaghetti

Both summer and winter squash come in a variety of colors, shapes and flavors. Summer squash mature much more quickly than winter, and are eaten fresh. The shells of winter squash harden as they mature, and if treated and stored properly, winter squash can last for months after harvest.

Soil and Fertilizer

Squash is a heavy feeder, so make sure the soil is particularly well-amended, and add a balanced fertilizer in addition to compost at planting. A balanced fertilizer applied to the side of the plant and watered in well may be needed again during the growing season.


Keep the soil consistently moist, especially when plants are young and again when they have set fruit, but avoid sogginess.


  • Harvest summer squash frequently to keep the squash coming. Don’t allow them to become bigger than their intended size, or they may become seedy and less flavorful.
  • Winter squash are ready to harvest when the rind gets hard and the skin takes on a dull cast. If the skin on the stem can’t be dented with a fingernail, the squash is ready. When harvesting winter squash, use a knife and leave a two-inch stem on the squash to help it last longer.
  • Some (butternut, spaghetti) but not all (acorn, delicata) winter squash need to be cured in order to keep for an extended period. Curing and storing winter squash.



Where, When and How to Plant Your Seedlings:

  • Melons want heat and sun, so they can be frustrating and challenging to grow in the Bay-side parts of Alameda County. In cooler microclimates, spread black or clear plastic mulch over smooth, weed-free soil about 3 weeks in advance of planting to raise soil temperature or grow near a cement path or driveway that holds heat and radiates it back to the plants.
  • Create mounds for planting, spacing 2 - 3 seedlings in each mound, about 2-3 feet apart. Make sure any taproot hasn't circled the pot before transplanting.
  • At planting, following the instructions on the package, apply slow-release fertilizer in a wide circle about 12 inches away from the seedling. Their roots really spread!


  • Using spun fabric row cover will hold in warmth and speed development. Remove the fabric as soon as the plant starts to flower to permit pollination.
  • To save space, support the vines on a trellis. You may also need slings to keep the vines from breaking with the weight of the fruit. If the fruit is on the ground, use wood, tile, or mulch material to lift fruits and avoid rot or insect damage.
  • Consider shading light-skinned melons in intense sunlight.


Keep the soil lightly moist, especially during flower and fruit development. Reduce watering a week before harvesting to prevent the fruit from becoming too watery.


To determine ripeness, look for fragrance increase, coarse skin netting, dried and browned tendrils, and color changes. Melons should be firm but slightly soft at the stem base with a slight crack where attached to the vine.

Special issues with cucumber, squash and melon

  • Squash, cucumber and melon can have difficulty getting pollinated so they can produce fruit. These curcurbits are pollinated only by bees flying between the separate male and female flowers collecting pollen from the male flower and leaving it on the females. If there are insufficient bees in your yard, you may need to hand-pollinate. Learn more about why squash can have trouble setting fruit. How you can hand-pollinate them. Planting ornamentals that draw bees may help for future years.
  • Many varieties of curcurbits are quite susceptible to powdery mildew. Powdery mildew is hard to control so prevention is the best bet. There are resistant varieties and giving the plants as much sun as possible and plenty of space for air circulation may help. Powdery mildew is the biggest problem in areas with moderate temperatures (60° to 80°F), as the fungus is sensitive to temperatures over 90 degrees. Learn more about what you can do about powdery mildew.

Additional resources