Zucchini

About it

Kind

Vegetables · Annual

Family

Cucurbitaceae

Hardiness zones

Zones 3–11

Frost

Tender — damaged by frost

Sun

Full sun

Spacing

24 in apart, rows 48 in

Soil depth in a pot

At least 12 in

Soil pH

6–7.5

Water

About every 7 days

When to plant

Start indoors

3 weeks before planting out

Plant out

Plant out 2 weeks after the last frost

Sow outdoors

Sow around the last frost

Soil temperature

Germinates from 60°F

Ready

About 50 days from sowing

Based on your last frost date. Outside the US, check local advice.

Varieties people grow

• Black Beauty— very dark green zucchini with white flesh
• Costata Romanesco— ribbed grey-green Italian type; nutty flavour
• Gold Rush— golden-yellow zucchini on a compact plant
• Raven— near-spineless, very dark green, compact

Planting partners

What has been claimed about growing Zucchini near other plants, grouped by how well it has been tested. Most companion planting advice has never been tested; the notes say which is which.

Tested in field trials

• With Green Beans Corn, climbing beans and squash grown together produced more per area of land than each alone in field trials, partly because their roots feed at different depths. PubMed Central ↗
• With Marigold In a Florida study, African marigolds planted with zucchini increased the natural enemies of aphids and slightly improved yield. UMN Extension ↗SARE ↗
• With Marigold In an Iowa study, marigolds planted with squash reduced damage from squash bugs and cucumber beetles. UMN Extension ↗
• With Nasturtium Nasturtiums planted with squash reduced squash bugs, and in an Iowa study reduced squash bug and cucumber beetle damage. UMN Extension ↗
• With Sweet Corn Corn, climbing beans and squash grown together produced more per area of land than each alone in field trials, partly because their roots feed at different depths. PubMed Central ↗

Safety for pets and children

• Cats Listed as non-toxic to cats (NC State Extension)
• Dogs Listed as non-toxic to dogs (NC State Extension)
• Horses Listed as non-toxic to horses (NC State Extension)
• Children No information in our sources

Read from NC State Extension ↗.

"No information" means our sources do not say, not that the plant is harmless. A non-toxic listing is not a reason to let anyone eat a plant.

Pests and diseases

• Powdery mildew Disease

  What you'll see. White powdery spots appear on the leaves in mid to late summer and can spread until whole leaves are covered, leaving fewer and smaller fruit.

  What helps. Choose resistant varieties, and give plants room and keep weeds down so air moves through the vines. Avoid heavy nitrogen feeding.

  Source: UMN Extension ↗,UMN Extension (2) ↗

• Squash bug Insect

  Anasa tristis

  What you'll see. Flat grey-brown bugs and their nymphs feed in groups under the leaves, leaving yellow spots that turn brown, and young plants can wilt and die.

  What helps. Crush the bronze egg clusters on leaf undersides and drop bugs into a pail of soapy water. Lay boards on the ground, then collect and destroy the bugs sheltering under them in the morning, and clear plant debris in fall.

  Source: UMN Extension ↗,UMN Extension (2) ↗

• Squash vine borer Insect

  What you'll see. A plant wilts, first in strong sun and then for good, and holes near the base of the stem are packed with sawdust-like droppings from the larvae feeding inside.

  What helps. Cover plants with row cover when the moths fly, take it off at flowering, and do not cover a bed where squash grew last year. A second sowing in early July matures after egg-laying is over, and plants a borer has killed should be pulled and destroyed.

  Timings in the source are for Minnesota, where the moths fly from late June through July.

  Source: UMN Extension ↗,UMN Extension (2) ↗

• Striped cucumber beetle Insect

  Acalymma vittatum

  What you'll see. Striped beetles chew the leaves, flowers and stems, and seedlings are hurt most.

  What helps. Cover young plants with row cover and take it off when flowers open so bees can reach them. Clear weeds, and remove garden debris in fall where the beetles spend the winter.

  Source: UMN Extension ↗,UMN Extension (2) ↗

Check the label and your local extension service before using any product.

Where this comes from

• direct sow weeks rel last frost cmg.extension.colostate.edu ↗ CSU #720 (Colorado) tender class: from seed around the date of the average last spring frost. UNH (New Hampshire) times direct seeding by soil warming to 70°F instead
• family npgsweb.ars-grin.gov ↗ GRIN page: Cucurbita pepo L.
• frost hardiness cmg.extension.colostate.edu ↗ CSU #720 (Colorado) tender class lists summer squash
• indoor start weeks cmg.extension.colostate.edu ↗ UNH (New Hampshire) 3-4 weeks, NC State (North Carolina) Table 16-3 summer squash 3-4, CSU #720 (Colorado) transplant age 2-3 and not more than 2-3 weeks for vine crops: 3 is in all three
• indoor start weeks NC State Extension ↗ UNH (New Hampshire) 3-4 weeks, NC State (North Carolina) Table 16-3 summer squash 3-4, CSU #720 (Colorado) transplant age 2-3 and not more than 2-3 weeks for vine crops: 3 is in all three
• indoor start weeks extension.unh.edu ↗ UNH (New Hampshire) 3-4 weeks, NC State (North Carolina) Table 16-3 summer squash 3-4, CSU #720 (Colorado) transplant age 2-3 and not more than 2-3 weeks for vine crops: 3 is in all three
• maturity counted from cmg.extension.colostate.edu ↗ Row's 50 days equals CSU #720 (Colorado) Table 2 summer squash 50 (unmarked) and NC State (North Carolina) Table 16-4's S=50-60 (T=30-40)
• maturity counted from NC State Extension ↗ Row's 50 days equals CSU #720 (Colorado) Table 2 summer squash 50 (unmarked) and NC State (North Carolina) Table 16-4's S=50-60 (T=30-40)
• min soil temp f cmg.extension.colostate.edu ↗ CSU #720 (Colorado) Table 2: summer squash germination minimum 60°F. UNH (New Hampshire) says sow when soil warms to 70°F
• Most facts The Old Farmer's Almanac ↗ Backfilled by 0041. Pre-0041 rows recorded one source for the whole row; per-field attribution was never captured and is not invented here.
• toxicity NC State Extension ↗ non_toxic for cat, dog, horse from its "non-toxic for" tags. Page matched to this row by its recorded species; not cited by the row before this batch.
• transplant weeks rel last frost extension.unh.edu ↗ UNH (New Hampshire) table: zucchini transplants 2 weeks after last frost. CSU #720 (Colorado): delay summer squash transplants until frost potential is over
• water frequency days UMN Extension ↗ UMN "Growing summer squash and zucchini": "Vine crops need about one inch of water from rainfall or irrigation each week during the growing season." and "Water sandy soils more often, but with lower amounts applied at any one time."