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.

The best time to plant cuphea in Portland should be estimated by checking out the USDA zone info.

Planting Calendar for Cuphea

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

You should not plant cuphea until after all chance of frost has passed because they are not cold tolerant.

The earliest that you can plant cuphea 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 cuphea and expect a good harvest is probably August. If you wait any later than that and your cuphea may not have a chance to grow to maturity. If you are starting your cuphea indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Portland. It might get as low as -15°F during the coldest months of winter.

Keep in mind that USDA zone info for Portland is an average and the actual date of last frost can change quite a bit from year to year. Half of the time in Portland it frosts late in the year after April 15 so make sure that you are prepared to protect your cuphea in the event of a 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.