One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You will be able to estimate when to plant sunflowers by reviewing the USDA zone info for Cupertino.

Planting Calendar for Sunflowers

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

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 Cupertino is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant sunflowers and expect a good harvest is probably September. If you wait any later than that and your sunflowers may not have a chance to fully mature. If you are starting your sunflowers indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Cupertino the average date of last frost happens on February 15. In the coldest months of winter you should expect an average low temperature of 25°F.

Remember that USDA zone info for Cupertino is not always accurate and the actual date of last frost will vary from year to year. Since half of the time in Cupertino last frost occurs after February 15 be ready to cover your sunflowers in the event of a late frost.

USDA Zone Info for Cupertino

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Cupertino

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