When to Plant Heliotrope in Grafton, WI

The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first opportunity to plant heliotrope in Grafton can be determined by reviewing 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.

Since heliotrope do not do well in cold weather it's necessary to wait until after the last frost when the weather gets warmer before you can plant them.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant heliotrope
Possibly ok, but a risky time to plant heliotrope
Probably not a good time to plant heliotrope

The earliest that you can plant heliotrope 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 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 really do well. Starting your heliotrope indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

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

Since the USDA zone info for Grafton may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Since half of the time in Grafton you get a frost after April 15 be ready to protect your heliotrope if you have a surprise 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.