One of the first steps you take when you are making a decision about 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.

The first opportunity to plant polygonums in Barstow should be figured out by reviewing the USDA zone info.

Planting Calendar for Polygonums

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

You can not plant polygonums until after the last frost has passed because they do not do well in cold weather.

The earliest that you can plant polygonums in Barstow 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. If you wait any later than that and 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 little bit earlier.

Last Frost Date

On average the last frost is on February 15 in Barstow. It might get as low as 20°F during the coldest months of winter.

It's important to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Barstow and it is different every year. Since half of the time in Barstow you get surprised by a frost after February 15 be ready to cover your polygonums in the event of a surprise late frost.

USDA Zone Info for Barstow

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 Barstow

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