Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By looking at the USDA zone info for Thornton you should be able to figure out when it's a good idea 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.

You can not plant cuphea until after the last frost when the weather gets warmer because they do not do well in cold weather.

The earliest that you can plant cuphea in Thornton 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 fully mature. Starting your cuphea indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Thornton. You should expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Thornton is not always accurate the actual date of last frost is different every year. Since half of the time in Thornton there is a last frost after April 15 be ready to protect your cuphea if you have one of those late frosts.

USDA Zone Info for Thornton

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 Thornton

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