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.

The best time to plant polygonums in Grass Valley should be determined by checking out the USDA zone info.

Planting Calendar for Polygonums

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

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 Grass Valley 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. You can get started a few weeks earlier by starting your polygonums indoors.

Last Frost Date

The average date of last frost is February 15 in Grass Valley. You should expect an average low temperature of 20°F in the coldest months of winter.

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 Grass Valley and it will vary from year to year. Half of the time in Grass Valley you get surprised by a frost after February 15 so just be sure to be ready to cover your polygonums if you have a surprise late frost.

USDA Zone Info for Grass Valley

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 Grass Valley

You may be interested in your other planting guides for Grass Valley.