When to Plant Heliotrope in Zone 1a

One of the first steps you take when you are making a decision about 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.

You can figure out when it's possible to plant heliotrope in Zone 1a by using the USDA zone info.


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 when the weather gets warmer before you can plant them.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant heliotrope
Possibly ok, but a risky time to plant heliotrope
Probably not a good time to plant heliotrope

The earliest that you can plant heliotrope in Zone 1a is June. However, you really should wait until July if you don't want to take any chances.

The last month that you can plant heliotrope and expect a good harvest is probably July. If you wait 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 few weeks earlier.

Last Frost Date

In Zone 1a the average date of last frost happens on June 15. You can expect an average low temperature of -60°F in the coldest months of winter.

Since the USDA zone info for Zone 1a may not be accurate from year to year the actual date of last frost will vary from year to year. Since half of the time in Zone 1a there is a last frost after June 15 be ready to cover your heliotrope if you have one of those late frosts.

USDA Zone Info for Zone 1a

Here is the info for USDA Zone 1a.

Average Date of Last Frost (spring)June 15
Average Date of First Frost (fall)July 15
Lowest Expected Low-60°F
Highest Expected Low-55°F

This means that on a really cold year, the coldest it will get is -60°F. On most years you should be prepared to experience lows near -55°F.

Plants to Grow in Zone 1a

You may be interested in your other planting guides for Zone 1a.