One of the first steps you take when you are figuring out your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By using the USDA zone info for San Diego you should be able to figure out when you can plant polygonums.

Planting Calendar for Polygonums

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

Since polygonums are not cold tolerant you have to wait until after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant polygonums in San Diego 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 really do well. 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 San Diego. You should expect an average low temperature of 20°F in the coldest months of winter.

Since the USDA zone info for San Diego is not always accurate the actual date of last frost is different every year. Since half of the time in San Diego there is a last frost after February 15 be ready to protect your polygonums in the event of a late frost.

USDA Zone Info for San Diego

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 San Diego

You may be interested in your other planting guides for San Diego.