One of the best tools that you have as gardeners to help us estimate 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.

You will be able to figure out when it's a good idea to plant polygonums by checking out the USDA zone info for Holtville.

Planting Calendar for Polygonums

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

Polygonums do not do well in cold weather which means that you really should wait until it warms up after all chance of frost has passed before you can plant them.

The earliest that you can plant polygonums in Holtville 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 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 grow to maturity. 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

On average the last frost is on January 31 in Holtville. In the coldest months of winter you can expect an average low temperature of 30°F.

Just be sure to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Holtville and it changes from year to year. Half of the time in Holtville last frost occurs after January 31 so always be ready to cover your polygonums if you have one of those late frosts.

USDA Zone Info for Holtville

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in Holtville

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