When to Plant Gladiolus in Sunnyvale, CA

The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. 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 you can plant gladiolus is to consult the USDA zone info for Sunnyvale.


Planting Calendar for Gladiolus

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

You can plant gladiolus a bit earlier in the year because they are barely cold tolerant.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant gladiolus
Possibly ok, but a risky time to plant gladiolus
Probably not a good time to plant gladiolus

The earliest that you can plant gladiolus in Sunnyvale 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 gladiolus and expect a good harvest is probably September. If you wait any later than that and your gladiolus may not have a chance to really do well. You can get started a couple of weeks earlier by starting your gladiolus indoors.

Last Frost Date

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

Since the USDA zone info for Sunnyvale is not always accurate the actual date of last frost can change quite a bit from year to year. Since half of the time in Sunnyvale it frosts late in the year after February 15 be ready to protect your gladiolus in the event of a 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 Low25°F
Highest Expected Low30°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.