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

A common way of figuring out when it's possible to plant heliotrope is to check out the USDA zone info for Romulus.

Planting Calendar for Heliotrope

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

Since heliotrope are not cold tolerant it is important to wait until after the last frost has passed before you can plant them.

The earliest that you can plant heliotrope in Romulus 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. If you are starting your heliotrope indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Romulus. You should expect an average low temperature of -10°F in the coldest months of winter.

Keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Romulus and it is different every year. Since half of the time in Romulus you get a frost after April 15 be ready to protect your heliotrope if you have one of those late frosts.

USDA Zone Info for Romulus

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Romulus

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