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.

By looking at the USDA zone info for San Jose you should be able to estimate when you can plant sunflowers.

Planting Calendar for Sunflowers

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

It's not a good 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 San Jose 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. You probably don't want to wait any later than that or else your sunflowers may not have a chance to grow to maturity. Starting your sunflowers indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In San Jose the average date of last frost happens on February 15. It might get as low as 25°F during the coldest months of winter.

Just be sure to remember that USDA zone info for San Jose is an average and the actual date of last frost is different every year. Since half of the time in San Jose you get a frost after February 15 be ready to cover your sunflowers if you have a late frost.

USDA Zone Info for San Jose

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 San Jose

You may be interested in your other planting guides for San Jose.