When to Plant Phlox in Brighton, CO

The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You will be able to determine when to plant phlox by using the USDA zone info for Brighton.


Planting Calendar for Phlox

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

Phlox do ok in moderate cold which tells us that you can plant them a bit earlier in the year than plants that are more sensitive to the cold.

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 Brighton 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. You can get started a couple of weeks earlier by starting your phlox indoors.

Last Frost Date

On average the last frost is on April 15 in Brighton. You should expect an average low temperature of -15°F in the coldest months of winter.

Keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Brighton and it can change quite a bit from year to year. Since half of the time in Brighton there is a last frost after April 15 be ready to protect your phlox if you have one of those late frosts.

USDA Zone Info for Brighton

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 Brighton

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