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

You should be able to figure out when it's possible to plant polygonums by referring to the USDA zone info for Las Vegas.

Planting Calendar for Polygonums

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

It's probably not a good idea to plant polygonums until after all chance of frost has passed because they do not do well in cold weather.

The earliest that you can plant polygonums in Las Vegas 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 fully mature. You can get started a little bit earlier by starting your polygonums indoors.

Last Frost Date

The average date of last frost is February 15 in Las Vegas. It might get as low as 20°F during the coldest months of winter.

Just be sure to remember that USDA zone info for Las Vegas is just an average and the actual date of last frost changes from year to year. Since half of the time in Las Vegas it frosts late in the year after February 15 be ready to protect your polygonums in the event of a late frost.

USDA Zone Info for Las Vegas

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 Las Vegas

You may be interested in your other planting guides for Las Vegas.