Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Exeter you can estimate when it's a good idea to plant heliotrope by reviewing the USDA zone info.

Planting Calendar for Heliotrope

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

Heliotrope do not do well in cold weather which tells us that you really should wait until it warms up after the last frost before you can plant them.

The earliest that you can plant heliotrope in Exeter is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant heliotrope and expect a good harvest is probably September. If you wait any later than that and your heliotrope may not have a chance to grow to maturity. 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

In Exeter the average date of last frost happens on February 15. You should expect an average low temperature of 25°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 Exeter and it is different every year. Half of the time in Exeter you get surprised by a frost after February 15 so always be ready to protect your heliotrope in the event of a late frost.

USDA Zone Info for Exeter

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Exeter

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