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 can figure out when it's possible to plant balloon flower in San Jose by using the USDA zone info.

Planting Calendar for Balloon Flower

Frost tolerance for balloon flower:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Balloon Flower do ok in moderate cold which tells us that you can plant them slightly earlier than other frost tender plants.

The earliest that you can plant balloon flower in San Jose 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 balloon flower and expect a good harvest is probably September. Any later than that and your balloon flower may not have a chance to grow to maturity. You can get started a little bit earlier by starting your balloon flower indoors.

Last Frost Date

The average date of last frost is February 15 in San Jose. In the coldest months of winter you can expect an average low temperature of 25°F.

Just be sure to remember that the actual date of last frost is an average because it is based on the USDA zone info for San Jose and it will vary from year to year. Half of the time in San Jose you get surprised by a frost after February 15 so make sure that you are ready to protect your balloon flower in the event of one of those late frosts.

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.