One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Berne can be looked at to figure out when it's the best time to plant heliotrope.

Planting Calendar for Heliotrope

Frost tolerance for heliotrope:	Not tolerant of frost.
When to plant:	After the last frost has passed.

Since heliotrope are not cold tolerant you must wait until after the last frost has passed before you can plant them.

The earliest that you can plant heliotrope 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 heliotrope and expect a good harvest is probably August. If you wait any later than that and your heliotrope may not have a chance to fully mature. If you are starting your heliotrope indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Berne the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of -10°F.

Just be sure to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Berne and it will vary from year to year. Since half of the time in Berne you get surprised by a frost after April 15 be ready to protect your heliotrope if you have a surprise 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.