When to Plant Alstromeria in Sonoma, CA

Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. 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 alstromeria in Sonoma can be figured out by using the USDA zone info.


Planting Calendar for Alstromeria

Frost tolerance for alstromeria: Tolerant of some frost.
When to plant: Up to 5 weeks before last frost.

You can plant alstromeria just a bit earlier in the year because they do well in moderate cold.

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

The earliest that you can plant alstromeria in Sonoma is January. However, you really should wait until February if you don't want to take any chances.

The last month that you can plant alstromeria and expect a good harvest is probably October. If you wait any later than that and your alstromeria may not have a chance to fully mature. If you are starting your alstromeria indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average all chance of frost has passed is on February 15 in Sonoma. It might get as low as 25°F during the coldest months of winter.

Remember that the actual date of last frost is just an average because it is based on the USDA zone info for Sonoma and it changes from year to year. Since half of the time in Sonoma you get surprised by a frost after February 15 be ready to cover your alstromeria if you have one of those late frosts.

USDA Zone Info for Sonoma

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 Sonoma

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