One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A common way of estimating when you can plant gomphrena is to refer to the USDA zone info for Riverside.

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.

You can plant gomphrena a bit earlier in the year because they are barely cold tolerant.

The earliest that you can plant gomphrena in Riverside is March. However, you really should wait until April 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. You probably don't want to wait any later than that or else your gomphrena may not have a chance to really do well. If you are starting your gomphrena indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Riverside the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of -10°F.

Keep in mind that USDA zone info for Riverside is not always accurate and the actual date of last frost can change quite a bit from year to year. Since half of the time in Riverside you get surprised by a frost after April 15 be ready to protect your gomphrena if you have a surprise late frost.

USDA Zone Info for Riverside

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Riverside

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