One of the best tools that you have as gardeners to help us determine 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.

In Sunnyvale you can determine when you can plant bells of ireland by looking at the USDA zone info.

Planting Calendar for Bells of Ireland

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

Since bells of ireland are barely cold tolerant you can plant them a bit earlier in the year than more sensitive plants.

The earliest that you can plant bells of ireland 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 bells of ireland and expect a good harvest is probably August. You probably don't want to wait any later than that or else your bells of ireland may not have a chance to grow to maturity. If you are starting your bells of ireland 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 March 15. You can expect an average low temperature of 10°F in the coldest months of winter.

Since the USDA zone info for Sunnyvale is just an average the actual date of last frost can change quite a bit from year to year. Half of the time in Sunnyvale you get a frost after March 15 so be sure to be ready to cover your bells of ireland in the event of a late frost.

USDA Zone Info for Sunnyvale

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 Sunnyvale

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