One of the best tools that you have as gardeners to help us figure out your gardening schedule is the 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 Marshall can be read to figure out when you can plant heliotrope.

Planting Calendar for Heliotrope

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

It's probably a bad idea to plant heliotrope until after the last frost when the weather gets warmer because they require warm weather.

The earliest that you can plant heliotrope in Marshall 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. You can get started a few weeks earlier by starting your heliotrope indoors.

Last Frost Date

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

Keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Marshall and it can change quite a bit from year to year. Half of the time in Marshall you get a frost after April 15 so just be sure to be ready to protect your heliotrope in the event of a late frost.

USDA Zone Info for Marshall

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 Marshall

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