When to Plant Phlox in Firestone, CO

One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

One way of figuring out when to plant phlox is to consult the USDA zone info for Firestone.


Planting Calendar for Phlox

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

You can plant phlox a little bit earlier in the year because they are moderately cold tolerant.

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

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

Last Frost Date

The average date of last frost is April 15 in Firestone. It might get as low as -15°F during the coldest months of winter.

Keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Firestone and it can change quite a bit from year to year. Half of the time in Firestone it frosts late in the year after April 15 so always be ready to protect your phlox 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.