Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By referring to the USDA zone info for Lisle you should be able to figure out when you can plant bidens.

Planting Calendar for Bidens

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

Since bidens are not cold tolerant it's necessary to wait until after the last frost has passed before you can plant them.

The earliest that you can plant bidens in Lisle 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 really do well. You can get started a couple of weeks earlier by starting your bidens indoors.

Last Frost Date

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

Always keep in mind that USDA zone info for Lisle is just an average and the actual date of last frost can change quite a bit from year to year. Since half of the time in Lisle there is a last frost after April 15 be ready to protect your bidens if you have a surprise late frost.

USDA Zone Info for Lisle

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 Lisle

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