The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Lewiston you can figure out when to plant heliotrope by looking at the USDA zone info.

Planting Calendar for Heliotrope

Frost tolerance for heliotrope:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

Since heliotrope do not do well in cold weather you need to wait until after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant heliotrope in Lewiston 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 fully mature. You can get started a little bit earlier by starting your heliotrope indoors.

Last Frost Date

The average date of last frost is April 15 in Lewiston. You can expect an average low temperature of 5°F in the coldest months of winter.

Remember that the actual date of last frost is an average because it is based on the USDA zone info for Lewiston and it can change quite a bit from year to year. Half of the time in Lewiston you get a frost after April 15 so make sure that you are ready to cover your heliotrope if you have a late frost.

USDA Zone Info for Lewiston

Here is the info for USDA Zone 7b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	5°F
Highest Expected Low	10°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 10°F.

Plants to Grow in Lewiston

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