One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Monrovia should be used to determine when you can plant polygonums.

Planting Calendar for Polygonums

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

Since polygonums are not cold tolerant it's necessary to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant polygonums in Monrovia 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 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

In Monrovia the average date of last frost happens on January 31. In the coldest months of winter you can expect an average low temperature of 30°F.

Remember that the actual date of last frost is an average because it is based on the USDA zone info for Monrovia and it can change quite a bit from year to year. Since half of the time in Monrovia you get a frost after January 31 be ready to protect your polygonums if you have a late frost.

USDA Zone Info for Monrovia

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 Monrovia

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