One of the first steps you take when you are getting a good idea your gardening schedule is find your 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.

You should be able to estimate when it's possible to plant heliotrope by using the USDA zone info for Santa Clara.

Planting Calendar for Heliotrope

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

Since heliotrope are not cold tolerant you really should wait until after the last frost before you can plant them.

The earliest that you can plant heliotrope in Santa Clara 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. Any later than that and your heliotrope may not have a chance to really do well. If you are starting your heliotrope indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

On average the last frost is on March 15 in Santa Clara. In the coldest months of winter you can expect an average low temperature of 10°F.

Just be sure to remember that USDA zone info for Santa Clara is just an average and the actual date of last frost is different every year. Since half of the time in Santa Clara you get surprised by a frost after March 15 be ready to cover your heliotrope if you have a late frost.

USDA Zone Info for Santa Clara

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°F

This means that on a really cold year, the coldest it will get is 10°F. On most years you should be prepared to experience lows near 15°F.

Plants to Grow in Santa Clara

You may be interested in your other planting guides for Santa Clara.