I recently had to figure out the best time to put rosemary outside, so I reached out to a gardening expert who works at a local garden center. She knew exactly what to do and shared several great tips to figure out when to do it, whether you start from a seed or a plant, and whether you use a pot or want to plant it directly in the ground.
I have written this post to share what I learned from talking to the expert.
The best time to put rosemary outside is in the spring, about three weeks after the last frost. Potted rosemary should be hardened off by being put outside during the day and inside at night for 3-4 weeks before staying outside for good.
Below, I have included all the information you need about when it is best to put rosemary outside, whether you start your rosemary plant from seed or already have a plant, and whether you are growing it in a pot or want to plant it outside in the ground.
Best Time to Put Rosemary Outside
The best time to put rosemary outside depends on several things, such as whether you start from a seed or already have a plant and whether you are growing it in a pot or want it to grow directly in the ground.
In this post, I cover everything you need to know, no matter which of the above ways you plan on using to grow your rosemary (even if you have already started).
The reason why I got interested in this topic is that I have had to put a rosemary plant outside myself. Since I didn’t know the best time to do it, I called a local garden center, where they have a phone line used only for gardening-related questions.
The expert gardener had a lot of first-hand experience growing rosemary and knew precisely how to help me. Here is what she said:
The best time to put rosemary outside is in the spring 3 weeks after the last frost. If your rosemary plant is in a pot, it is best to do it gradually. Start 3 weeks after the last frost and bring it outside during the day and back inside at night for 3-4 weeks to harden off before leaving it outside.
Another thing that is important when putting rosemary outside is knowing how to find the best place for it. Lucky for you, I have written a post about just that which you can find here.
As you can hear, the best time to put rosemary outside depends on how you grow it, so below, I cover everything you need to know. I also share some excellent tips the expert gardener I spoke to gave me about putting rosemary outside, whether you start from seed, plant, and whether you want to use a pot or plant it directly in the ground.
Best Time to Put Potted Rosemary Outside
Potten rosemary is much easier to manage than rosemary growing directly in the ground, primarily because you can move it around as you please.
The best time to put potted rosemary outside is three weeks after the last frost. After that, it is best to do it gradually by putting the plant outside when it is light and back inside when it is dark for 3-4 weeks before leaving the plant outside all the time.
Being able to move your potted rosemary around is a huge advantage, especially in winter, as you can move it inside to spare it from the cold and then just put it back outside in the spring when it is starting to get warmer.
There are advantages and disadvantages to growing rosemary in a pot compared to directly in the ground, but both can work just fine if you do it right. I recommend reading this post if you are not sure which way is right for you.
Whether you start with a seed or already have a rosemary plant, you need to harden the plant before putting it outside. Hardening off your rosemary plant will make it easier for it to adapt to being outside and will result in a healthier plant. Luckily, it is super easy. I cover how to do it below.
Best Way to Harden off Rosemary Before Putting It Outside
I actually didn’t think about how important it is to harden off rosemary plants before putting them outside before I spoke to an expert from my local garden center, but it turns out it is not only a really good idea but also really easy.
The best way to harden off rosemary plants before putting them outside is to expose the plant more and more to the outside gradually. Take it out during the day and back inside at night for about 3-4 weeks before leaving your potted rosemary outside.
This tip is essential to follow as the cold weather at night can damage the plant, but if you want to put a rosemary plant outside later in the spring or the summer when it is warmer, hardening it off is actually also a really good idea since suddenly being exposed to a lot of sunlight can also damage the plant, especially if it is young.
Hardening off rosemary to protect it from too much sun is slightly different than hardening it off to protect it from the cold.
The best way to harden off rosemary to protect it from too much sun is to take it out in the evening and leave it until the early afternoon the next day. Do this for 3-4 weeks before leaving the plant outside all the time.
Doing it that way allows your plant to get some sunlight in the morning, but spares it of the intense afternoon sun which can sometimes be too much for very young plants.
Below, I cover the best time to plant rosemary outside in the ground.
Best Time to Plant Rosemary Outside in the Ground
When rosemary plants are big and well-established, they can survive a lot and even survive winters with frost, but when the plants are young, they are more fragile.
The best time to plant rosemary in the ground is in the spring, at least three weeks after the last frost, and if the weather is still rough, it can be a good idea to wait 2-3 more weeks.
If you have a young, small rosemary plant or want to start one from seed, however, it is important that you put it outside at the right time of the year, as it can be damaged, both by too cold weather and too much sun.
If you are starting from seed, you should start it indoors in a small pot and leave it there for about 2-3 months before it is ready to go outside. I have a full guide on how to sow rosemary seeds on this link.
If you need some help with transplanting your rosemary into the ground, I recommend reading the article on this link, where I explain the process and show photos of how to do it.
Here are some more tips the gardener from my local garden center taught me.
Tips for Putting Rosemary Outside if Starting From Seed
If you are starting your rosemary plant from a seed, the gardener I spoke to before writing this post had some tips that are great to know.
Here are the tips I learned from the expert I spoke to.
- Plant the seeds around the time of the last frost.
- Plant your rosemary seeds indoors and let them grow for a month before putting them out.
- Harden off your rosemary seedlings by keeping them outside during the day and inside at night for about a month and then let them stay outside. Start this once they are about a month old.
Once your seedlings have become more established, and there is no risk of frost outside, it is time for them to go outside, so go back up and read the part about when to put potted rosemary outside.
I hope this guide was helpful!