One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can determine when it's a good idea to plant heliotrope in Oregon by looking at 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.

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

The earliest that you can plant heliotrope in Oregon 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 grow to maturity. You can get started a few weeks earlier by starting your heliotrope indoors.

Last Frost Date

In Oregon the average date of last frost happens on April 15. It might get as low as -20°F during the coldest months of winter.

Keep in mind that USDA zone info for Oregon is not always accurate and the actual date of last frost will vary from year to year. Half of the time in Oregon you get a frost after April 15 so just be sure to be ready to cover your heliotrope if you have a surprise late frost.

USDA Zone Info for Oregon

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Oregon

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