One of the best tools that you have as gardeners to help us figure out your gardening schedule is the 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.

A common way of making a decision about when it's the best time to plant iresene is to consult the USDA zone info for Sunnyvale.

Planting Calendar for Iresene

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

Since iresene require warm weather you really should wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant iresene in Sunnyvale 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 iresene and expect a good harvest is probably September. You probably don't want to wait any later than that or else your iresene may not have a chance to really do well. If you are starting your iresene indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Sunnyvale 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.

Always keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Sunnyvale and it can change quite a bit from year to year. Since half of the time in Sunnyvale you get a frost after February 15 be ready to cover your iresene in the event of a surprise late frost.

USDA Zone Info for Sunnyvale

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 Sunnyvale

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