When to Plant Cosmos in Sierra Vista, AZ

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.

You can estimate when it's possible to plant cosmos in Sierra Vista by using the USDA zone info.


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 just a tiny bit earlier in the year because they are one of those plants that can tolerate a tiny bit of cold weather.

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 Sierra Vista 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 cosmos and expect a good harvest is probably August. You probably don't want to wait any later than that or else your cosmos may not have a chance to fully mature. Starting your cosmos indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average the last frost has passed is on March 15 in Sierra Vista. It might get as low as 15°F during the coldest months of winter.

Since the USDA zone info for Sierra Vista may not be accurate from year to year the actual date of last frost is different every year. Since half of the time in Sierra Vista there is a last frost after March 15 be ready to protect your cosmos if you have one of those late frosts.

USDA Zone Info for Sierra Vista

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)March 15
Average Date of First Frost (fall)November 15
Lowest Expected Low15°F
Highest Expected Low20°F

This means that on a really cold year, the coldest it will get is 15°F. On most years you should be prepared to experience lows near 20°F.

Plants to Grow in Sierra Vista

You may be interested in your other planting guides for Sierra Vista.