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

One way of getting a good idea when it's the best time to plant heliotrope is to examine the USDA zone info for Pullman.

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 when the weather gets warmer because they are not cold tolerant.

The earliest that you can plant heliotrope in Pullman 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. You probably don't want to wait any later than that or else your heliotrope may not have a chance to really do well. Starting your heliotrope indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Pullman. In the coldest months of winter you can expect an average low temperature of -5°F.

Since the USDA zone info for Pullman may not be accurate from year to year the actual date of last frost is different every year. Since half of the time in Pullman last frost occurs after April 15 be ready to protect your heliotrope in the event of a late frost.

USDA Zone Info for Pullman

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Pullman

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