One of the best tools that you have as gardeners to help us estimate 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 Portland you can figure out when to plant snow-in summer by looking at the USDA zone info.

Planting Calendar for Snow-in Summer

Frost tolerance for snow-in summer:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Since snow-in summer are moderately cold tolerant you can plant them a bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant snow-in summer in Portland is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant snow-in summer and expect a good harvest is probably September. Any later than that and your snow-in summer may not have a chance to really do well. If you are starting your snow-in summer indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Portland. In the coldest months of winter you should expect an average low temperature of -15°F.

Since the USDA zone info for Portland is not always accurate the actual date of last frost can change quite a bit from year to year. Since half of the time in Portland there is a last frost after April 15 be ready to protect your snow-in summer in the event of one of those late frosts.

USDA Zone Info for Portland

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 Portland

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