One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

It's possible to figure out when you can plant alyssum by looking at the USDA zone info for San Jose.

Planting Calendar for Alyssum

Frost tolerance for alyssum:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Alyssum do ok in a bit of cold which tells us that you can plant them a lot earlier in the year than other frost tender plants.

The earliest that you can plant alyssum in San Jose is January. However, you really should wait until February if you don't want to take any chances.

The last month that you can plant alyssum and expect a good harvest is probably October. You probably don't want to wait any later than that or else your alyssum may not have a chance to fully mature. Starting your alyssum indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average the last frost is on February 15 in San Jose. You can expect an average low temperature of 25°F in the coldest months of winter.

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 changes from year to year. Since half of the time in San Jose you get surprised by a frost after February 15 be ready to cover your alyssum if you have 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.