When to Plant Heliotrope in Silvis, IL

One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

It's possible to figure out when it's possible to plant heliotrope by checking out the USDA zone info for Silvis.


Planting Calendar for Heliotrope

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

Since heliotrope are not cold tolerant you must wait until after the last frost 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 Silvis 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. You probably don't want to wait any later than that or else your heliotrope may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your heliotrope indoors.

Last Frost Date

In Silvis the average date of last frost happens on April 15. It might get as low as -15°F during the coldest months of winter.

Remember that USDA zone info for Silvis 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 Silvis you get surprised by a frost after April 15 be ready to cover your heliotrope in the event of one of those late frosts.

USDA Zone Info for Silvis

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 Silvis

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