One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A common way of estimating when you can plant heliotrope is to look at the USDA zone info for Dubuque.

Planting Calendar for Heliotrope

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

It's not a good idea to plant heliotrope until after the last frost has passed because they do not do well in cold weather.

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

Last Frost Date

On average all chance of frost has passed is on April 15 in Dubuque. You can expect an average low temperature of -20°F in the coldest months of winter.

Just be sure to remember that USDA zone info for Dubuque may not be accurate from year to year and the actual date of last frost will vary from year to year. Since half of the time in Dubuque last frost occurs after April 15 be ready to protect your heliotrope if you have a surprise late frost.

USDA Zone Info for Dubuque

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Dubuque

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