One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A way of figuring out when it's the best time to plant sunflowers is to consult the USDA zone info for Berne.

Planting Calendar for Sunflowers

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

Sunflowers require warm weather which tells us that you really should wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant sunflowers in Berne 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 sunflowers and expect a good harvest is probably August. You probably don't want to wait any later than that or else your sunflowers may not have a chance to grow to maturity. If you are starting your sunflowers 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 Berne. In the coldest months of winter you can expect an average low temperature of -10°F.

Always keep in mind that USDA zone info for Berne is just an average and the actual date of last frost is different every year. Since half of the time in Berne you get surprised by a frost after April 15 be ready to cover your sunflowers in the event of a late frost.

USDA Zone Info for Berne

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 Berne

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