One of the first steps you take when you are getting a good idea your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A way of determining when you can plant dahlias is to consult the USDA zone info for Williams.

Planting Calendar for Dahlias

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

Dahlias do not do well in cold weather which means that it is necessary to wait until it warms up after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant dahlias in Williams 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. Any later than that and your dahlias may not have a chance to grow to maturity. If you are starting your dahlias indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Williams the average date of last frost happens on February 15. It might get as low as 25°F during the coldest months of winter.

Always keep in mind that USDA zone info for Williams is not always accurate and the actual date of last frost is different every year. Half of the time in Williams there is a last frost after February 15 so be sure to be ready to cover your dahlias if you have one of those late frosts.

USDA Zone Info for Williams

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 Williams

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