When to Plant Cosmos in El Monte, 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.

It's a good idea to determine when it's a good idea to plant cosmos by looking at the USDA zone info for El Monte.


Planting Calendar for Cosmos

Frost tolerance for cosmos: Tolerant of a very small amount of frost.
When to plant: Up to 3 weeks before last frost.

Cosmos are barely cold tolerant which tells us that you can plant them slightly earlier than plants that are more sensitive to the cold.

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

The earliest that you can plant cosmos in El Monte is February. However, you really should wait until March if you don't want to take any chances.

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

Last Frost Date

On average the last frost has passed is on January 31 in El Monte. It might get as low as 30°F during the coldest months of winter.

Just be sure to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for El Monte and it can change quite a bit from year to year. Half of the time in El Monte there is a last frost after January 31 so make sure that you are ready to cover your cosmos in the event of one of those late frosts.

USDA Zone Info for El Monte

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 El Monte

You may be interested in your other planting guides for El Monte.