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

The first chance to plant polygonums in Zone 9a should be determined by referring to the USDA zone info.

Planting Calendar for Polygonums

Frost tolerance for polygonums:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Since polygonums require warm weather it's important to wait until after the last frost has passed before you can plant them.

The earliest that you can plant polygonums in Zone 9a 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. Any later than that and your polygonums may not have a chance to fully mature. Starting your polygonums indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Zone 9a the average date of last frost happens on February 15. It might get as low as 20°F during the coldest months of winter.

Remember that the actual date of last frost is just an average because it is based on the USDA zone info for Zone 9a and it can change quite a bit from year to year. Since half of the time in Zone 9a there is a last frost after February 15 be ready to cover your polygonums if you have a late frost.

USDA Zone Info for Zone 9a

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°F

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

Plants to Grow in Zone 9a

You may be interested in your other planting guides for Zone 9a.