The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By checking out the USDA zone info for Marengo you will be able to figure out when it's possible to plant bidens.

Planting Calendar for Bidens

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

Bidens are not cold tolerant which means that you need to wait until it warms up after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant bidens in Marengo 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. You probably don't want to wait any later than that or else your bidens may not have a chance to fully mature. Starting your bidens indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Marengo. You should expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Marengo is an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Marengo you get surprised by a frost after April 15 be ready to protect your bidens if you have a surprise late frost.

USDA Zone Info for Marengo

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Marengo

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