One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first opportunity to plant dahlias in Orinda should be determined by using the USDA zone info.

Planting Calendar for Dahlias

Frost tolerance for dahlias:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Since dahlias are not cold tolerant it's important to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant dahlias in Orinda 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. Starting your dahlias indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

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

Since the USDA zone info for Orinda may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Half of the time in Orinda you get surprised by a frost after February 15 so make sure that you are prepared to protect your dahlias in the event of one of those late frosts.

USDA Zone Info for Orinda

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 Orinda

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