The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A common way of getting a good idea when to plant bidens is to refer to the USDA zone info for Park Ridge.

Planting Calendar for Bidens

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

It's not a good idea to plant bidens until after the last frost because they are not cold tolerant.

The earliest that you can plant bidens in Park Ridge 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 grow to maturity. If you are starting your bidens indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Park Ridge the average date of last frost happens on April 15. You should expect an average low temperature of -15°F in the coldest months of winter.

It's important to remember that the actual date of last frost is an average because it is based on the USDA zone info for Park Ridge and it changes from year to year. Half of the time in Park Ridge it frosts late in the year after April 15 so just be sure to be ready to protect your bidens if you have one of those late frosts.

USDA Zone Info for Park Ridge

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 Park Ridge

You may be interested in your other planting guides for Park Ridge.