The USDA Zone info is a great tool for gardeners to help us figure out 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.

The first chance to plant dianthus in Palo Alto should be determined by reviewing the USDA zone info.

Planting Calendar for Dianthus

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

Dianthus do ok in some cold which means that you can plant them a little earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant dianthus in Palo Alto 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. Any later than that and 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 little bit earlier.

Last Frost Date

On average the last frost has passed is on February 15 in Palo Alto. It might get as low as 25°F during the coldest months of winter.

Since the USDA zone info for Palo Alto is not always accurate the actual date of last frost changes from year to year. Half of the time in Palo Alto it frosts late in the year after February 15 so just be sure to be ready to protect your dianthus in the event of a late frost.

USDA Zone Info for Palo Alto

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 Palo Alto

You may be interested in your other planting guides for Palo Alto.