One of the best tools that you have as gardeners to help us estimate 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.

In Pleasanton you can figure out when it's possible to plant dahlia by looking at the USDA zone info.

Planting Calendar for Dahlia

Frost tolerance for dahlia:	Not tolerant of frost.
When to plant:	After the last frost.

You can not plant dahlia until after the last frost because they are not cold tolerant.

The earliest that you can plant dahlia in Pleasanton 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 dahlia and expect a good harvest is probably September. You probably don't want to wait any later than that or else your dahlia may not have a chance to fully mature. If you are starting your dahlia indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

The average date of last frost is February 15 in Pleasanton. It might get as low as 20°F during the coldest months of winter.

Since the USDA zone info for Pleasanton is not always accurate the actual date of last frost will vary from year to year. Half of the time in Pleasanton last frost occurs after February 15 so just be sure to be ready to cover your dahlia if you have a surprise late frost.

USDA Zone Info for Pleasanton

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°F

This means that on a really cold year, the coldest it will get is 20°F. On most years you should be prepared to experience lows near 25°F.

Plants to Grow in Pleasanton

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