Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for San Jose should be reffered to in order to determine when it's possible to plant dianthus.

Planting Calendar for Dianthus

Frost tolerance for dianthus:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Dianthus do well in a little bit of cold which means that you can plant them a bit earlier in the year than other frost tender plants.

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

Last Frost Date

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

Always keep in mind that USDA zone info for San Jose may not be accurate from year to year and the actual date of last frost changes from year to year. Half of the time in San Jose last frost occurs after February 15 so make sure that you are prepared to cover your dianthus 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.