When to Plant Sweet Williams in Firestone, CO

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.

The USDA zone info for Firestone should be used to estimate when you can plant sweet williams.


Planting Calendar for Sweet Williams

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

Sweet Williams do well in moderate cold which means that you can start planting them earlier than other plants that might not handle the cold.

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

The earliest that you can plant sweet williams in Firestone 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 sweet williams and expect a good harvest is probably September. Any later than that and your sweet williams may not have a chance to grow to maturity. If you are starting your sweet williams indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Firestone the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of -15°F.

Since the USDA zone info for Firestone is not always accurate the actual date of last frost will vary from year to year. Since half of the time in Firestone last frost occurs after April 15 be ready to cover your sweet williams if you have a late frost.

USDA Zone Info for Firestone

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low-15°F
Highest Expected Low-10°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 -10°F.

Plants to Grow in Firestone

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