One of the first steps you take when you are figuring out your gardening schedule is find your 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.

A common way of estimating when you can plant dianthus is to examine the USDA zone info for Zone 9b.

Planting Calendar for Dianthus

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

Since dianthus are moderately cold tolerant you can plant them a little bit earlier in the year than other frost tender plants.

The earliest that you can plant dianthus in Zone 9b 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. If you are starting your dianthus indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

On average the last frost is on February 15 in Zone 9b. In the coldest months of winter you can expect an average low temperature of 25°F.

Since the USDA zone info for Zone 9b is just an average the actual date of last frost will vary from year to year. Since half of the time in Zone 9b there is a last frost after February 15 be ready to protect your dianthus in the event of a surprise late frost.

USDA Zone Info for Zone 9b

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 Zone 9b

You may be interested in your other planting guides for Zone 9b.