Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The best time to plant heliotrope in De Pere should be determined by using the USDA zone info.

Planting Calendar for Heliotrope

Frost tolerance for heliotrope:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

It's probably a bad idea to plant heliotrope until after all chance of frost has passed because they are not cold tolerant.

The earliest that you can plant heliotrope in De Pere 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. Starting your heliotrope indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in De Pere. It might get as low as -20°F during the coldest months of winter.

Since the USDA zone info for De Pere is an average the actual date of last frost can change quite a bit from year to year. Half of the time in De Pere last frost occurs after April 15 so just be sure to be ready to cover your heliotrope in the event of one of those late frosts.

USDA Zone Info for De Pere

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in De Pere

You may be interested in your other planting guides for De Pere.