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 way of getting a good idea when it's a good idea to plant polygonums is to examine the USDA zone info for Riverbank.

Planting Calendar for Polygonums

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

Since polygonums do not do well in cold weather you have to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant polygonums in Riverbank 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 polygonums and expect a good harvest is probably September. You probably don't want to wait any later than that or else your polygonums may not have a chance to fully mature. If you are starting your polygonums indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

The average date of last frost is February 15 in Riverbank. In the coldest months of winter you should expect an average low temperature of 25°F.

Always keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Riverbank and it can change quite a bit from year to year. Since half of the time in Riverbank last frost occurs after February 15 be ready to cover your polygonums in the event of one of those late frosts.

USDA Zone Info for Riverbank

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°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 30°F.

Plants to Grow in Riverbank

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