When to Plant Zucchini in Washington, IL

One of the first steps you take when you are making a decision about your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The best time to plant zucchini in Washington can be figured out by looking at the USDA zone info.


Planting Calendar for Zucchini

Frost tolerance for zucchini: Not tolerant of frost.
When to plant: After all chance of frost has passed.

You really shouldn't plant zucchini until after all chance of frost has passed because they do not do well in cold weather.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant zucchini
Possibly ok, but a risky time to plant zucchini
Probably not a good time to plant zucchini

The earliest that you can plant zucchini in Washington is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant zucchini and expect a good harvest is probably August. If you wait any later than that and your zucchini may not have a chance to fully mature. Starting your zucchini indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Washington. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Washington may not be accurate from year to year the actual date of last frost will vary from year to year. Since half of the time in Washington there is a last frost after April 15 be ready to cover your zucchini in the event of a surprise late frost.

USDA Zone Info for Washington

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low-15°F
Highest Expected Low-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Washington

You may be interested in your other planting guides for Washington.