When to Plant Alyssum in Millbrae, CA

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.

The USDA zone info for Millbrae should be reviewed to estimate when it's the best time to plant alyssum.


Planting Calendar for Alyssum

Frost tolerance for alyssum: Very tolerant of frost.
When to plant: Up to 7 weeks before last frost.

You can plant alyssum much earlier in the year because they are one of those plants that can tolerate quite a bit of cold weather.

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

The earliest that you can plant alyssum in Millbrae 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 alyssum and expect a good harvest is probably October. If you wait any later than that and your alyssum may not have a chance to grow to maturity. If you are starting your alyssum 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 January 31 in Millbrae. It might get as low as 30°F during the coldest months of winter.

Since the USDA zone info for Millbrae 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 Millbrae it frosts late in the year after January 31 be ready to protect your alyssum if you have one of those late frosts.

USDA Zone Info for Millbrae

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)January 31
Average Date of First Frost (fall)December 15
Lowest Expected Low30°F
Highest Expected Low35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in Millbrae

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