One of the best tools that you have as gardeners to help us determine your gardening schedule is the 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.

In Tualatin you can figure out when it's the best time to plant zucchini by looking at the USDA zone info.

Planting Calendar for Zucchini

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

You really shouldn't plant zucchini until after the last frost because they require warm weather.

The earliest that you can plant zucchini in Tualatin 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. Any later than that and your zucchini may not have a chance to fully mature. If you are starting your zucchini indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average the last frost is on March 15 in Tualatin. In the coldest months of winter you should expect an average low temperature of 15°F.

Since the USDA zone info for Tualatin may not be accurate from year to year the actual date of last frost changes from year to year. Since half of the time in Tualatin you get surprised by a frost after March 15 be ready to cover your zucchini in the event of a late frost.

USDA Zone Info for Tualatin

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°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 20°F.

Plants to Grow in Tualatin

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