The USDA Zone info is a great tool for gardeners to help us estimate 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.

The USDA zone info for Grafton should be used to determine when it's possible 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 the last frost before you can plant them.

The earliest that you can plant bidens in Grafton 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 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

On average the last frost has passed is on April 15 in Grafton. In the coldest months of winter you can expect an average low temperature of -15°F.

Keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Grafton and it will vary from year to year. Since half of the time in Grafton you get surprised by a frost after April 15 be ready to protect your bidens if you have a late frost.

USDA Zone Info for Grafton

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 Grafton

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