When to Plant Rosemary in Lone Tree, CO

Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By reviewing the USDA zone info for Lone Tree it's possible to figure out when it's a good idea to plant rosemary.


Planting Calendar for Rosemary

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

Rosemary are very cold tolerant which tells us that you can plant them a quite a bit earlier than other plants that might not handle the cold.

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

The earliest that you can plant rosemary in Lone Tree 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 rosemary and expect a good harvest is probably September. Any later than that and your rosemary may not have a chance to fully mature. You can get started a little bit earlier by starting your rosemary indoors.

Last Frost Date

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

Just be sure to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Lone Tree and it is different every year. Since half of the time in Lone Tree there is a last frost after April 15 be ready to cover your rosemary in the event of one of those late frosts.

USDA Zone Info for Lone Tree

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 Lone Tree

You may be interested in your other planting guides for Lone Tree.