One of the first steps you take when you are making a decision about 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.

In San Jose you can figure out when it's the best time to plant gladiolus by referring to the USDA zone info.

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.

Gladiolus are one of those plants that can tolerate a tiny bit of cold weather which tells us that you can get them planted just a bit earlier than more sensitive plants.

The earliest that you can plant gladiolus 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 gladiolus and expect a good harvest is probably September. Any later than that and your gladiolus may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your gladiolus indoors.

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.

Always keep in mind that USDA zone info for San Jose is just an average and the actual date of last frost will vary from year to year. Half of the time in San Jose there is a last frost after February 15 so be sure to be ready to cover your gladiolus 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.