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.

A common way of determining when it's the best time to plant heliotrope is to check out the USDA zone info for National City.

Planting Calendar for Heliotrope

Frost tolerance for heliotrope:	Not tolerant of frost.
When to plant:	After the last frost.

Heliotrope require warm weather which means that it's necessary to wait until it warms up after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant heliotrope in National City 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. Any later than that and your heliotrope may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your heliotrope indoors.

Last Frost Date

In National City the average date of last frost happens on January 31. You can expect an average low temperature of 35°F in the coldest months of winter.

Keep in mind that USDA zone info for National City is just an average and the actual date of last frost will vary from year to year. Since half of the time in National City last frost occurs after January 31 be ready to cover your heliotrope in the event of a late frost.

USDA Zone Info for National City

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 National City

You may be interested in your other planting guides for National City.