Before planting it is a good idea to find your USDA Zone info to determine 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.

The earliest that you can plant sunflowers in Santa Clara should be estimated by checking out the USDA zone info.

Planting Calendar for Sunflowers

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

It's probably a bad idea to plant sunflowers until after the last frost has passed because they do not do well in cold weather.

The earliest that you can plant sunflowers 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 sunflowers and expect a good harvest is probably August. If you wait any later than that and your sunflowers may not have a chance to fully mature. You can get started a little bit earlier by starting your sunflowers indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on March 15 in Santa Clara. You should expect an average low temperature of 10°F in the coldest months of winter.

Always keep in mind that USDA zone info for Santa Clara may not be accurate from year to year and the actual date of last frost is different every year. Half of the time in Santa Clara you get a frost after March 15 so always be ready to protect your sunflowers in the event of 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.