Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

One way of making a decision about when it's possible to plant polygonums is to check out the USDA zone info for Corona.

Planting Calendar for Polygonums

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

You can not plant polygonums until after the last frost because they require warm weather.

The earliest that you can plant polygonums in Corona 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 fully mature. Starting your polygonums indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average all chance of frost has passed is on February 15 in Corona. In the coldest months of winter you should expect an average low temperature of 25°F.

Remember that USDA zone info for Corona is not always accurate and the actual date of last frost is different every year. Since half of the time in Corona you get surprised by a frost after February 15 be ready to cover your polygonums in the event of a late frost.

USDA Zone Info for Corona

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 Corona

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