The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

It's a good idea to determine when it's possible to plant gomphrena by referring to the USDA zone info for Riverton.

Planting Calendar for Gomphrena

Frost tolerance for gomphrena:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Gomphrena tend to make it in some cold which means that you can plant them slightly earlier in the year than other frost tender plants.

The earliest that you can plant gomphrena in Riverton 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 gomphrena and expect a good harvest is probably August. If you wait any later than that and your gomphrena may not have a chance to fully mature. Starting your gomphrena indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is May 15 in Riverton. It might get as low as -25°F during the coldest months of winter.

Keep in mind that USDA zone info for Riverton is not always accurate and the actual date of last frost is different every year. Half of the time in Riverton it frosts late in the year after May 15 so make sure that you are ready to cover your gomphrena if you have a surprise late frost.

USDA Zone Info for Riverton

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Riverton

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