One of the best tools that you have as gardeners to help us figure out your gardening schedule is the 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.

By reviewing the USDA zone info for Yelm you should be able to determine when you can plant heliotrope.

Planting Calendar for Heliotrope

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

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

The earliest that you can plant heliotrope in Yelm 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 grow to maturity. 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

On average all chance of frost has passed is on March 15 in Yelm. It might get as low as 10°F during the coldest months of winter.

Since the USDA zone info for Yelm is just an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Yelm you get surprised by a frost after March 15 be ready to cover your heliotrope in the event of a surprise late frost.

USDA Zone Info for Yelm

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°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 15°F.

Plants to Grow in Yelm

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