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.

One way of determining when to plant runner beans is to consult the USDA zone info for Diamond Bar.

Planting Calendar for Runner beans

Frost tolerance for runner beans:	Not tolerant of frost.
When to plant:	After the last frost.

Runner beans do not do well in cold weather which tells us that it's important to wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant runner beans in Diamond Bar 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 runner beans and expect a good harvest is probably September. You probably don't want to wait any later than that or else your runner beans may not have a chance to fully mature. Starting your runner beans indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average the last frost has passed is on January 31 in Diamond Bar. In the coldest months of winter you should expect an average low temperature of 30°F.

Since the USDA zone info for Diamond Bar is just an average the actual date of last frost will vary from year to year. Since half of the time in Diamond Bar you get a frost after January 31 be ready to protect your runner beans in the event of a late frost.

USDA Zone Info for Diamond Bar

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 Diamond Bar

You may be interested in your other planting guides for Diamond Bar.