Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By reviewing the USDA zone info for Los Altos you will be able to figure out when to plant dahlia.

Planting Calendar for Dahlia

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

Dahlia require warm weather which tells us that it's important to wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant dahlia in Los Altos 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. Any later than that and your dahlia may not have a chance to really do well. 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

The average date of last frost is February 15 in Los Altos. You should expect an average low temperature of 25°F in the coldest months of winter.

Remember that USDA zone info for Los Altos may not be accurate from year to year and the actual date of last frost is different every year. Half of the time in Los Altos it frosts late in the year after February 15 so be sure to be ready to cover your dahlia if you have a surprise late frost.

USDA Zone Info for Los Altos

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 Los Altos

You may be interested in your other planting guides for Los Altos.