Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

It's a good idea to determine when to plant heliotrope by looking at the USDA zone info for Somerville.

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 Somerville 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 Somerville. It might get as low as -5°F during the coldest months of winter.

Since the USDA zone info for Somerville may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Since half of the time in Somerville it frosts late in the year after April 15 be ready to protect your heliotrope if you have a late frost.

USDA Zone Info for Somerville

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 Somerville

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