One of the best tools that you have as gardeners to help us determine 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.

By reviewing the USDA zone info for Aspen it's a good idea to determine when it's the best time to plant cuphea.

Planting Calendar for Cuphea

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

It's probably a bad idea to plant cuphea until after the last frost has passed because they are not cold tolerant.

The earliest that you can plant cuphea in Aspen 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. 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

In Aspen the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of -15°F.

It's important to remember that the actual date of last frost is an average because it is based on the USDA zone info for Aspen and it will vary from year to year. Half of the time in Aspen it frosts late in the year after April 15 so make sure that you are ready to protect your cuphea if you have a surprise late frost.

USDA Zone Info for Aspen

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 Aspen

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