One of the best tools that you have as gardeners to help us figure out your gardening schedule is the 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.

You can figure out when it's a good idea to plant dahlias in Highland by using the USDA zone info.

Planting Calendar for Dahlias

Frost tolerance for dahlias:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

Dahlias are not cold tolerant which tells us that you have to wait until it warms up after all chance of frost has passed before you can plant them.

The earliest that you can plant dahlias in Highland is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant dahlias and expect a good harvest is probably September. If you wait any later than that and your dahlias may not have a chance to fully mature. You can get started a few weeks earlier by starting your dahlias indoors.

Last Frost Date

The average date of last frost is February 15 in Highland. It might get as low as 25°F during the coldest months of winter.

Since the USDA zone info for Highland is an average the actual date of last frost changes from year to year. Half of the time in Highland you get a frost after February 15 so be sure to be ready to protect your dahlias in the event of a surprise late frost.

USDA Zone Info for Highland

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 Highland

You may be interested in your other planting guides for Highland.