When to Plant Thyme in Longmont, CO

One of the first steps you take when you are figuring out your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The first chance to plant thyme in Longmont can be determined by using the USDA zone info.


Planting Calendar for Thyme

Frost tolerance for thyme: Very tolerant of frost.
When to plant: Up to 7 weeks before last frost.

Since thyme do well in cold you can plant them quite a bit earlier in the year than other frost tender plants.

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

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

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Longmont. 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 Longmont and it can change quite a bit from year to year. Half of the time in Longmont you get a frost after April 15 so always be ready to protect your thyme if you have one of those late frosts.

USDA Zone Info for Longmont

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 Longmont

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