When to Plant Cosmos in Coronado, CA

One of the first steps you take when you are figuring out 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.

A way of making a decision about when it's a good idea to plant cosmos is to examine the USDA zone info for Coronado.


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.

You can plant cosmos a bit earlier in the year because they are barely cold tolerant.

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 Coronado 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 fully mature. If you are starting your cosmos indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on January 31 in Coronado. It might get as low as 35°F during the coldest months of winter.

Keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Coronado and it can change quite a bit from year to year. Half of the time in Coronado last frost occurs after January 31 so make sure that you are prepared to protect your cosmos if you have a surprise late frost.

USDA Zone Info for Coronado

Here is the info for USDA Zone 10b.

Average Date of Last Frost (spring)January 31
Average Date of First Frost (fall)December 15
Lowest Expected Low35°F
Highest Expected Low40°F

This means that on a really cold year, the coldest it will get is 35°F. On most years you should be prepared to experience lows near 40°F.

Plants to Grow in Coronado

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