One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Portland should be read to figure out when it's a good idea to plant impatiens.

Planting Calendar for Impatiens

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

Impatiens do not do well in cold weather which means that you must wait until it warms up after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant impatiens in Portland 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 impatiens and expect a good harvest is probably August. Any later than that and your impatiens may not have a chance to fully mature. Starting your impatiens indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Portland the average date of last frost happens on April 15. You can expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Portland is not always accurate the actual date of last frost is different every year. Since half of the time in Portland you get a frost after April 15 be ready to cover your impatiens in the event of a surprise late frost.

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.