One of the first steps you take when you are making a decision about 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.

The USDA zone info for Larkspur can be read to determine when it's possible to plant argyranthemum.

Planting Calendar for Argyranthemum

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

Since argyranthemum require warm weather it's necessary to wait until after the last frost before you can plant them.

The earliest that you can plant argyranthemum in Larkspur 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 argyranthemum and expect a good harvest is probably September. You probably don't want to wait any later than that or else your argyranthemum may not have a chance to fully mature. If you are starting your argyranthemum indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

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

Since the USDA zone info for Larkspur is just an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Larkspur you get a frost after February 15 be ready to protect your argyranthemum in the event of a surprise late frost.

USDA Zone Info for Larkspur

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 Larkspur

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