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.

The USDA zone info for Signal Hill should be looked at 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.

Heliotrope require warm weather which tells us that you need to wait until it warms up after the last frost before you can plant them.

The earliest that you can plant heliotrope in Signal Hill is February. However, you really should wait until March 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. If you wait any later than that and your heliotrope may not have a chance to grow to maturity. Starting your heliotrope indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is January 31 in Signal Hill. You should expect an average low temperature of 35°F in the coldest months of winter.

Remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Signal Hill and it changes from year to year. Since half of the time in Signal Hill you get surprised by a frost after January 31 be ready to cover your heliotrope if you have a late frost.

USDA Zone Info for Signal Hill

Here is the info for USDA Zone 10b.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	35°F
Highest Expected Low	40°F

This means that on a really cold year, the coldest it will get is 35°F. On most years you should be prepared to experience lows near 40°F.

Plants to Grow in Signal Hill

You may be interested in your other planting guides for Signal Hill.