Rosemary is a popular herb that is often used in Mediterranean cooking and goes great with lamb and potatoes. Rosemary is actually part of the mint family but is certainly not as invasive as many mint plants. So, you might be asking whether rosemary is a perennial.
Rosemary is a perennial but can be grown also as an annual. To grow rosemary as a perennial in USDA hardiness zones 7 and below you need to bring it inside when the temperature drops below 30 degrees Fahrenheit (-1 degree Celsius).
Let’s discuss the growth pattern of a rosemary plant.
Growing Rosemary As a Perennial Outdoors
In many parts of the world, rosemary can be grown as an outdoor perennial. Many people like to have a rosemary bush in their herb garden or at the edge of their vegetable patch. Rosemary also makes a lovely hedging plant as it can be pruned and shaped quite successfully.
If you live in USDA hardiness zones 8 and above, you’ll be delighted to learn that you can grow this hardy Mediterranean herb outdoors all year round. Growth will slow down during the colder months, but your plant will survive and put on plenty of new growth in the spring.
Make sure that you harvest your rosemary often so that the shrub forms a nice rounded growth habit. When pruning, try not to cut into any of the woody growth as this could kill the plant itself. Tip pruning is much better to keep your plant looking nice and bushy.
Growing Rosemary As a Perennial In Pots
Because rosemary can be trained into a lovely bush, it’s ideal for growing in pots, and many gardeners prefer to do this. If you live in USDA hardiness zones 7 and below, this is definitely something that you should consider.
This is because rosemary grown outdoors in these areas will not survive the winter, and your plant will die if you leave it outdoors during the freezing temperatures.
Therefore, growing your rosemary in a lovely large pot will allow you to bring it indoors over the colder months and put it back out once all dangers of frost are over.
How Long Will Rosemary Live When Grown Outdoors In Warmer Climates?
Generally, a rosemary plant can live for ten years or more as long as it is given the right conditions. It’s important to remember that rosemary does not like cold winters and shouldn’t be exposed to freezing temperatures.
That’s why gardeners who live in cold regions will generally grow this lovely culinary herb in a pot that they can bring indoors once the temperature gets too cold. Many people also like to grow rosemary in the kitchen on a sunny windowsill. This makes it quite handy when you want to harvest a few sprigs to use in your cooking.
How To Condition Your Rosemary Before Bringing It Indoors
Because rosemary needs plenty of light, it’s a good idea to condition your plant before you bring it in for the winter. To do this, move the potted rosemary close to your house into a spot that is protected from any early frosts.
Bring your rosemary indoors as soon as the temperature drops below 30 degrees Fahrenheit (-1 degrees Celsius). It’s best to put your pot in a nice bright spot that is also nice and warm.
As soon as any chance of frost has passed again, it’s safe to put your rosemary back outside. All you have to do is reverse the process that you used to condition your plant before bringing it indoors.
If you do this every year, then you’ll have a thriving rosemary plant for many years to come.
Can You Grow Rosemary As An Annual?
If you don’t fancy growing your rosemary in a pot and bringing it indoors every winter and you live in a colder climate, then you’ll have no choice but to grow rosemary as an annual and replant it every year in spring.
The only other advantage to doing this is that your plant won’t become quite as woody as one grown as a perennial, but it also won’t get as large and bushy.
While you can purchase a new plant each year from your local garden center, a better way is to propagate new plants from your existing ones. Bear in mind that these will need to be propagated indoors if you get really cold winters.
On the plus side, rosemary is fairly easy to propagate from stem cuttings. When taking your cuttings, choose nice green tips that are not too soft but don’t have any woody growth yet.
Fill a tray or small pot with some good quality potting soil or seed raising mix. Remove the bottom leaves of your cuttings but leave a few leaves at the top. Dip the cut end into some rooting hormone and place the cuttings into the soil, spacing them evenly.
It’s best to use a pencil or dibbler to make a small hole before putting your cutting into the mix. This avoids rubbing off the rooting hormone that you’ve just applied.
Place your pot or cutting tray on a nice bright windowsill indoors. Keep the cuttings nice and moist to ensure that they will root successfully. However, ensure that the plants don’t get waterlogged. Otherwise, they may rot. It should take around 6 to 8 weeks for your cuttings to start to produce roots and some new growth.
Rosemary cuttings can also be successfully started in water. Just fill a clean glass jar with water and put your cuttings into this. Ensure that none of the leaves are sitting in the water.
Put your glass with the cuttings on a bright windowsill and remember to change the water every few days in order to keep it fresh. Starting your cuttings this way means that you can observe the root growth as it happens.
Once the plants have put on plenty of roots, you can pot them up into some good quality potting mix, and they’ll be ready to plant outside again once the danger of frost is over.