The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A way of determining when it's a good idea to plant bidens is to check out the USDA zone info for Los Altos.

Planting Calendar for Bidens

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

It's a bad idea to plant bidens until after all chance of frost has passed because they do not do well in cold weather.

The earliest that you can plant bidens 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 bidens and expect a good harvest is probably September. Any later than that and your bidens may not have a chance to fully mature. If you are starting your bidens indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average the last frost has passed is on February 15 in Los Altos. In the coldest months of winter you should expect an average low temperature of 25°F.

Remember that USDA zone info for Los Altos is just an average and the actual date of last frost can change quite a bit from year to year. Half of the time in Los Altos you get a frost after February 15 so be sure to be ready to protect your bidens if you have a 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.