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

One way of making a decision about when to plant heliotrope is to refer to the USDA zone info for Manitowoc.

Planting Calendar for Heliotrope

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

Heliotrope are not cold tolerant which means that you have to wait until it warms up after the last frost before you can plant them.

The earliest that you can plant heliotrope in Manitowoc 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. Any later than that and your heliotrope may not have a chance to grow to maturity. If you are starting your heliotrope indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Manitowoc. In the coldest months of winter you should expect an average low temperature of -15°F.

Just be sure to remember that USDA zone info for Manitowoc is not always accurate and the actual date of last frost can change quite a bit from year to year. Since half of the time in Manitowoc last frost occurs after April 15 be ready to cover your heliotrope in the event of one of those late frosts.

USDA Zone Info for Manitowoc

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 Manitowoc

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