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 Portland you can estimate when it's the best time 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.

Since heliotrope do not do well in cold weather you really should wait until after the last frost before you can plant them.

The earliest that you can plant heliotrope in Portland 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. 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 little bit earlier.

Last Frost Date

In Portland the average date of last frost happens on February 15. It might get as low as 25°F during the coldest months of winter.

It's important to remember that USDA zone info for Portland is an average and the actual date of last frost will vary from year to year. Since half of the time in Portland you get surprised by a frost after February 15 be ready to cover your heliotrope if you have a surprise late frost.

USDA Zone Info for Portland

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 Portland

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