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

In Rio Grande City you can estimate when you can plant polygonums by looking at 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.

Polygonums do not do well in cold weather which means that you have to wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant polygonums in Rio Grande City 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. Any later than that and your polygonums may not have a chance to grow to maturity. Starting your polygonums indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on February 15 in Rio Grande City. It might get as low as 25°F during the coldest months of winter.

Since the USDA zone info for Rio Grande City is not always accurate the actual date of last frost changes from year to year. Half of the time in Rio Grande City you get a frost after February 15 so make sure that you are prepared to protect your polygonums in the event of one of those late frosts.

USDA Zone Info for Rio Grande City

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Rio Grande City

You may be interested in your other planting guides for Rio Grande City.