The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Riverside you can figure out when to plant bishop's weed by looking at the USDA zone info.

Planting Calendar for Bishop's Weed

Frost tolerance for bishop's weed:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Bishop's Weed can survive in quite a bit of cold which tells us that you can plant them quite a bit earlier in the year than more sensitive plants.

The earliest that you can plant bishop's weed in Riverside is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant bishop's weed and expect a good harvest is probably September. You probably don't want to wait any later than that or else your bishop's weed may not have a chance to fully mature. Starting your bishop's weed indoors is a great way to get them started 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 can expect an average low temperature of -10°F.

Keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Riverside and it is different every year. Half of the time in Riverside you get surprised by a frost after April 15 so make sure that you are ready to cover your bishop's weed if you have one of those late frosts.

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.