One of the first steps you take when you are determining your gardening schedule is find your 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.

The best time to plant dahlia in Holtville should be determined by using the USDA zone info.

Planting Calendar for Dahlia

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

Dahlia are not cold tolerant which means that it is important to wait until it warms up after the last frost before you can plant them.

The earliest that you can plant dahlia in Holtville is February. However, you really should wait until March 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. If you wait any later than that and 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 few weeks earlier.

Last Frost Date

In Holtville the average date of last frost happens on January 31. In the coldest months of winter you can expect an average low temperature of 30°F.

It's important to remember that USDA zone info for Holtville may not be accurate from year to year and the actual date of last frost changes from year to year. Half of the time in Holtville there is a last frost after January 31 so always be ready to protect your dahlia if you have one of those late frosts.

USDA Zone Info for Holtville

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in Holtville

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