The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A common way of estimating when to plant pumpkins is to look at the USDA zone info for Lake Oswego.

Planting Calendar for Pumpkins

Frost tolerance for pumpkins:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

It's probably not a good idea to plant pumpkins until after the last frost because they are not cold tolerant.

The earliest that you can plant pumpkins in Lake Oswego 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 pumpkins and expect a good harvest is probably August. If you wait any later than that and your pumpkins may not have a chance to fully mature. If you are starting your pumpkins indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Lake Oswego the average date of last frost happens on March 15. In the coldest months of winter you should expect an average low temperature of 15°F.

Since the USDA zone info for Lake Oswego is just an average the actual date of last frost will vary from year to year. Half of the time in Lake Oswego you get surprised by a frost after March 15 so be sure to be ready to protect your pumpkins in the event of one of those late frosts.

USDA Zone Info for Lake Oswego

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 Lake Oswego

You may be interested in your other planting guides for Lake Oswego.