One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By checking out the USDA zone info for Waterloo it's a good idea to estimate when it's a good idea to plant bidens.

Planting Calendar for Bidens

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

Since bidens do not do well in cold weather you have to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant bidens in Waterloo 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. 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 few weeks earlier.

Last Frost Date

On average all chance of frost has passed is on April 15 in Waterloo. You should expect an average low temperature of -10°F in the coldest months of winter.

Always keep in mind that USDA zone info for Waterloo may not be accurate from year to year and the actual date of last frost can change quite a bit from year to year. Half of the time in Waterloo there is a last frost after April 15 so be sure to be ready to cover your bidens if you have a surprise late frost.

USDA Zone Info for Waterloo

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Waterloo

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