When to Plant Catharanthus in Larkspur, CA

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

The first opportunity to plant catharanthus in Larkspur can be estimated by reviewing the USDA zone info.


Planting Calendar for Catharanthus

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

You should not plant catharanthus until after all chance of frost has passed because they are not cold tolerant.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant catharanthus
Possibly ok, but a risky time to plant catharanthus
Probably not a good time to plant catharanthus

The earliest that you can plant catharanthus 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 catharanthus and expect a good harvest is probably September. You probably don't want to wait any later than that or else your catharanthus may not have a chance to grow to maturity. Starting your catharanthus indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Larkspur the average date of last frost happens on February 15. You can expect an average low temperature of 25°F in the coldest months of winter.

It's important to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Larkspur and it changes from year to year. Half of the time in Larkspur there is a last frost after February 15 so be sure to be ready to protect your catharanthus in the event of one of those late frosts.

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 Low25°F
Highest Expected Low30°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.