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.

The best time to plant bidens in Rolla should be determined by checking out the USDA zone info.

Planting Calendar for Bidens

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

You should not plant bidens until after the last frost because they do not do well in cold weather.

The earliest that you can plant bidens in Rolla is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant bidens and expect a good harvest is probably August. If you wait any later than that and your bidens may not have a chance to fully mature. If you are starting your bidens indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Rolla the average date of last frost happens on April 15. It might get as low as -5°F during the coldest months of winter.

Since the USDA zone info for Rolla is an average the actual date of last frost will vary from year to year. Since half of the time in Rolla you get a frost after April 15 be ready to protect your bidens if you have a surprise late frost.

USDA Zone Info for Rolla

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Rolla

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