Do you want to grow rosemary in Colorado, but don’t know when to plant them?
Planting rosemary is not as easy as it seems.
- Rosemary are not able to survive frost or cold weather under 50 degrees Fahrenheit.
So if you plant them outside too early in the spring they will die. And if you plant them too late, your rosemary won’t produce a harvest before the first frost arrives in the fall.
Today, I’m going to teach you the ideal time to plant rosemary in Colorado:
- To Learn More About HOW to Grow Rosemary, Check Out This GUIDE!
When to Plant Rosemary in Colorado
As you may have already guessed, you need to pay very close attention to your local weather in the spring. Specifically, you are going to need to watch when the last frost occurs.
In general, when there hasn’t been a frost for two weeks, you are SAFE to plant your rosemary outside in Colorado!
For your reference, I have created this table for average frost dates for most major cities in Colorado. If your city is not listed below you can find its Last & First Frost Dates HERE.
Colorado Last & First Frost Dates
Unfortunately, Mother Nature plays cruel tricks on us every year.
It should be noted that the above dates are just averages.
There are years when the last frost comes MUCH later. Sometimes, the last frost happens much earlier and you can get your rosemary planted outside in Colorado much quicker.
Like I said before, you need to be very diligent in checking your local weather.
So what happens if a frost comes AFTER you plant your rosemary?
When you know a frost is coming you need to take action.
- If rosemary are in pots, bring them inside
- If rosemary are in the ground, cover them in burlap and hope they survive
Also, make sure not to plant your rosemary in your garden too late.
- Planting rosemary too late will cause small rosemary or even worse, no rosemary.
When Should You Start Your Rosemary Seeds Indoors?
Depending on the type of rosemary, it takes roughly 80-100 days to grow rosemary from seed indoors and then transplant them to your garden.
For a specific date that you should start rosemary seeds indoors you should:
- Find the last average frost date HERE
- And then subtract 100 days from it
Not only this, but I recommend again paying close attention to your local weather report.
It should also be noted that the best technique for bringing your rosemary plants outside is to introduce them (in their pots) outside for an hour. And then increase the amount of time they spend outside each day by an hour until they have been outside for 8 hours.
This will “hardened” your rosemary plant, increasing its chances of fighting off diseases, insects, droughts, and wet conditions.
If you want to learn WHEN to plant ANY Vegetable in Colorado, head over to HERE and just type in the vegetable you want to grow.