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.

The USDA zone info for Portland can be read to determine when it's the best time to plant sweet peas.

Planting Calendar for Sweet Peas

Frost tolerance for sweet peas:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

You can plant sweet peas a bit earlier in the year because they are one of those plants that can tolerate a tiny bit of cold weather.

The earliest that you can plant sweet peas in Portland is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant sweet peas and expect a good harvest is probably August. Any later than that and your sweet peas may not have a chance to fully mature. Starting your sweet peas indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In Portland 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.

Remember that USDA zone info for Portland is not always accurate and the actual date of last frost will vary from year to year. Since half of the time in Portland last frost occurs after March 15 be ready to cover your sweet peas if you have one of those late frosts.

USDA Zone Info for Portland

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 Portland

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