One of the first steps you take when you are estimating 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.

The USDA zone info for Rock Falls should be read to determine when it's possible to plant heliotrope.

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 it's necessary to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant heliotrope in Rock Falls 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. You can get started a little bit earlier by starting your heliotrope indoors.

Last Frost Date

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

Always keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Rock Falls and it can change quite a bit from year to year. Half of the time in Rock Falls it frosts late in the year 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 Rock Falls

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 Rock Falls

You may be interested in your other planting guides for Rock Falls.