Rosemary Care: How to Grow Rosemary in Pots and Containers


How to grow and care for rosemary in pots and containers

Rosemary is possibly my favorite Mediterranean herb. It is hardy, tastes great, and is incredibly easy to grow once you get the conditions right. I use it in my cooking all the time.

In its natural habitat, rosemary grows in well-draining soils, full sun, and infrequent rainfall. To grow rosemary successfully in pots and containers, we need to emulate these conditions.

I have grown rosemary all my life and have accrued lots of experience growing and caring for rosemary in my job at a garden nursery.

In this article, I share with you all the tips, techniques, and secrets that I learned from my own experience and on my trips to Mediterranean countries, speaking directly with growers to make sure your rosemary thrives…

Plant rosemary in pots with a well-draining potting mix of 30% grit and 70% compost. Grow rosemary in clay or terracotta pots 12 inches across in full sun and water rosemary every 2 weeks with a thorough watering, so excess water trickles out the base of the pot.

For those of you in a rush, I created a table summarizing the main points of rosemary care:

How to Care for Rosemary in Pots and Containers:Requirements:
Pots Size:Choose a pot at least 12 inches across with the same proportionate depth
Best Type of Pot For Rosemary:Clay, ceramic or terracotta work best as they are porous and dry evenly.
How Often to Water Rosemary in Pots:Water rosemary every 2 weeks with a generous soak in the Spring and Summer if there has been no significant rainfall. Do not water outdoor potted rosemary in Fall and Winter
Potting Soil for Rosemary:Plant rosemary in potting soil composed of 30% horticultural sand or grit to 70% multipurpose compost.
Soil pH:The optimal soil pH is 6.5-7 and can grow in the pH range of normal multipurpose compost.
Fertilizer:Do not add fertilizer as this decreases the concentration of essential oils and the taste and aroma of the leaves, as it is contrary to the preferred conditions.
When to Prune Rosemary:Prune in Spring anytime after the threat of frost up until the middle of Summer.
How to Prune Rosemary:Cut back the top 4 inches or so (or the top third) of the rosemary to stimulate new growth and create a bushy appearance.
Cold Hardy:Mature rosemary can tolerate a light frost but in cold climates use horticultural fleece to prevent frost damage or bring the pot indoors for Winter and place it in a sunny window.
Winter Care:Protect rosemary from frost. Bring potted rosemary indoors and place it in a sunny window. Water once every 4-6 weeks if indoors during Winter with a generous soak.

Please keep reading to learn how to grow and care for rosemary in pots and containers so that they produce leaves with the strongest fragrance and best taste, and to for my the best tips so that the potted rosemary survives Winter…

Best Pots and Containers for Rosemary

Clay and terracotta pots are my favorite choice of pots for growing rosemary. Clay and terracotta have a porous structure to allow the potting soil to dry out more evenly after watering to avoid root rot. I really like Clay and terracotta as they do not heat up as quickly as plastic pots in the sun and resist weather better.

Of course, our rosemary plants are Mediterranean herbs and grow in well-draining, gritty soil that does not hold moisture around the roots.

Whilst you do not need to be in Mediterranean climate to grow rosemary it is important to emulate some of the conditions by ensuring the soil can dry out evenly.

Choose a clay or terracotta pot for growing rosemary as the material is porous which allows the soil to dry evenly rather then plastic pots which can retain too much moisture and risk root rot, because in my experience root rot is the most common reason rosemary plants die back.

Rosemary grow best in terracotta pots.
This is a photo of the terracotta pot in which I am about to plant my rosemary. As you can see, I am using very sandy soil to improve the drainage.

I must emphasize that the most important characteristic of any rosemary pot or container is that it has drainage holes in the base to allow excess water to escape after watering to allow the soil to dry between bouts of watering, which helps us mimic the conditions of the rosemary’s native environment.

Pro tip: Ideally, I would choose a pot that is at least 12 inches across. This size ensures the rosemary’s roots have enough room to establish and that the pot has a large enough capacity for soil, which acts as insulation to the rosemary’s roots (the roots are the most cold-sensitive part of the rosemary), which is obviously very important if you live in a climate with freezing temperatures in Winter.

What I love to do is prop my rosemary pot on ‘feet’ or stones to elevate the pot off the ground to ensure water can drain freely from the bottom of the pot after watering. This is a way I prevent my rosemary suffering root rot.

(Read my article, choosing the best pots for rosemary).

Planting Rosemary in Pots and Containers

Rosemary is a Mediterranean herb that has adapted to growing in gritty, well-draining soils on mountainsides in countries such as Spain.

Therefore to grow rosemary in pots and containers, we should strive to emulate these seemingly harsh Mediterranean soil conditions for the rosemary to produce leaves with the strongest flavor and aroma.

I have experimented with lots of potting soils over the years, and I have concluded that my rosemary plants grow best in potting soil composed of 30% horticultural sand or grit and 70% compost. Rosemary grows best in slightly acidic soils of pH 6.5-7, with a high inorganic content, aerated, well-draining structure, and relatively low soil fertility.

Rosemary can grow in a wide range of soils but pH 6.5-7 is optimal which is well within the typical range of most multipurpose compost and potting soils.

The most important soil characteristic for rosemary is good drainage, so add approximately 30% horticultural sand or grit (by volume of the pot) and 70% multipurpose compost to emulate the soil drainage of the rosemary’s native Mediterranean hillside environment and ensure that moisture drains efficient away from the roots after watering to avoid root rot.

Rosemary grows best in a sandy soil mix to improve drainage.
I recommend that you always use horticultural sand rather than normal sand, as the particle size is larger, which means better drainage and reduces the risk of root rot.

If you live in a climate of high rainfall, then I recommend being more generous with the sand and grit to counter the effects of all the rainfall and ensure the optimal balance of moisture for rosemary to thrive.

In my experience, grit does perform slightly better then sand as a soil amendment in high rainfall.

When I was under the tutelage of commercial growers of Mediterranean herbs, they taught me that too much grit is always better than not enough to ensure good drainage is essential.

As we discussed, the most common reason for rosemary dying is root rot which we can easily avoid by planting our rosemary in pots with good drainage and watering them with the right frequency.

(Read my article, how to revive a dying rosemary plant).

Before planting your rosemary in the pot, I recommend adding a 1-inch layer of gravel to the bottom of the pot or container which prevents the drainage holes from becoming blocked by compacted soil and ensures good drainage.

Rosemary Pot and Container Care- Watering

What’s the most important aspect of caring for potted rosemary? Watering!

I must emphasize the importance of watering rosemary in pots and containers with a generous soak so that excess water trickles out of the pot’s base. Overwatering is the most common reason rosemary plants die, so wait until the top 4 inches of the soil dry before watering again.

I was taught that watering rosemary thoroughly encourages the roots to grow deeper and properly establish in the potting mix, which further increases the rosemary’s resistance to drought.

If you water too lightly, then only the top inch or so of the soil becomes moist which causes the roots to grow near the surface of the potting soil and reduces the growth and resilience of the rosemary.

How Often to Water Rosemary in Pots

Conditions:How Often to Water Rosemary:
Spring and Summer:Water every 2 weeks. If there has been significant rainfall, wait until the soil is dry before watering again.
Newly Planted Rosemary:Water every week in the Spring and Summer. Do not water in the Fall or Winter if left outdoors.
Rosemary in Fall and Winter:Rosemary is dormant in Winter so stop watering rosemary at the start of Fall to reduce the risk of root rot.
Rosemary Indoors over Winter:Water rosemary once very 4-6 weeks if indoors over Winter.

Rosemary is a drought-resistant herb that thrives in well-draining potting soils and requires watering less frequently than most plants. So, if you’re like me and occasionally forget to water your potted plants, I can assure you that rosemary is very forgiving!

If there has been no rainfall, I water my potted and container rosemary once a week in the hottest and driest weeks of Summer. In cooler climates with overcast weather, I water rosemary every two weeks. Always wait until the soil feels somewhat dry before watering again.

In climates with mild Winters in which you can keep potted rosemary outdoors, the rosemary does not require any additional watering in the Fall and Winter as it is in a dormant state and can attain the required moisture from the environment.

In colder climates, rosemary must be brought indoors to protect it from cold (or you can just wrap yours up with horticultural fleece to protect it from frost like me). In this case, rosemary should be watered every 4-6 weeks with a good soak.

Rosemary requires significantly less frequent watering as the plant is dormant, and there is a higher risk of root rot in the Winter.

Watering once every 4-6 weeks in the Winter strikes the balance of ensuring the rosemary has enough moisture to survive but does not risk root rot.

(Read my article, how often to water rosemary).

Potted Rosemary Care in Winter

Rosemary is not cold hardy, so bring your pots indoors in climates with freezing Winter temperatures or use horticultural fleece to protect rosemary against frost. If indoors, locate your potted rosemary in as much sun as possible and water every 4-6 weeks to prevent the rosemary from drying out completely.

Rosemary is a Mediterranean herb that has adapted to living in climates with mild Winters that do not experience frost and is cold hardy to USDA zone 6.

Some rosemary varieties can tolerate light frost but if you want to ensure their survival over Winter, I have had great success using horticultural fleece to insulate my rosemary at night or you can bring the pot indoors a place it in a sunny window.

In colder climates the importance of well draining soil and larger pots increases. A larger pot has the capacity for more soil which acts as insulation for the cold sensitive roots.

Pro tip: I always use a nice big pot that is proportionately larger than my rosemary plant when I grow rosemary in cold climates, as the soil is the best form of insulation for its roots. I combine this with using horticultural fleece, and my rosemary now survives every Winter!

Rosemary is at greatest risk of root rot in Winter as cold temperatures typically mean damp soils that stay moist for a long time (which promote the conditions for root rot and fungal diseases to thrive).

As we discussed, if you live in a colder climate with more rainfall, it is imperative to use lots of grit in the potting mix to increase the aeration of the soil and improve drainage.

Grit does not hold onto moisture in the same way that organic material does, so it is the perfect soil amendment for growing rosemary and countering damp conditions in Winter. If you do not have horticultural grit to hand, I have also used succulent and cacti soil successfully as a soil amendment.

Where to Grow Rosemary in Pots and Containers

When I was strolling the hills in Spain near Mount Tibidabo, I saw rosemary growing on the hillsides in its native Mediterranean environment, enjoying the full sun.

While we don’t need to live near Barcelona to grow rosemary, we do need to replicate some of the conditions of its native environment to get the best out of our potted rosemary.

Locate your potted rosemary in an area of your garden with full sun (at least 6 hours) with some airflow around the foliage. The commercial growers told me that the more sunlight, the higher the concentration of essential oils in the rosemary’s leaves, increasing its aroma and flavor.

Rosemary is grown commercially in hot and dry countries around the Mediterranean, in blazing sunshine with warm temperatures and an occasional breeze. It thrives in these conditions.

If you grow your Rosemary in the shade, I tend to find it grows leggy, and the leaves do not smell as strong, flower, or have the same culinary value without several hours of direct sunlight.

Try to avoid placing your potted rosemary in a corner or anywhere without an occasional breeze. Some airflow helps to dry the foliage after rainfall and overhead watering and reduces humidity, which prevents fungal disease.

(Read my articles on why is my rosemary turning brown, yellow or black).

How and When to Prune Rosemary– Pots and Container Care

Prune rosemary anytime in Spring after the threat of frost has passed and anytime in Summer. I must caution you against pruning in the fall as this stimulates new growth that is more vulnerable to frost damage.

Pro tip: Pruning your rosemary every year stimulates new growth and encourages a bushier, more productive, rounded plant.

Pruning is very simple. All you have to do is cut off the top third or the top 3 or 4 inches of growth with a sharp pair of pruners. This encourages newer growth, which hosts the leaves with a higher concentration of essentials that are responsible for the aroma and taste of rosemary.

What I do is prune my rosemary as and when I require it for cooking, but I typically only prune in the Spring or Summer. If you want to enjoy the taste of rosemary all year round, try cutting it in Summer and freezing it as rosemary retains its flavor when defrosted for cooking.

Please read my article, How to Propagate Rosemary from Cuttings.

Key Takeaways:

  • Clay and terracotta pots are the best choices for growing rosemary. They are porous, allowing the soil to dry evenly, and are thicker than plastic pots or planters. This means they do not dry out as quickly, bake hard, and resist frost better in the Winter.
  • Grow rosemary in pots and containers at least 12 inches across. A pot this size has enough soil to insulate the rosemary’s roots from frost in Winter.
  • Rosemary is a drought-resistant herb that should only be watered when the soil around the roots has dried out. Water the rosemary thoroughly so that excess water trickles from the pot’s base, then wait for the soil to dry before watering again.
  • Plant rosemary in a potting mix that is 70% compost and 30% horticultural sand or grit. A gritty potting mix ensures the soil has a porous structure for good drainage, which emulates the soil conditions of rosemary’s native hillside and the gritty soil conditions in its natural environment.
  • Grow rosemary in full sun (at least 6 hours). More hours of sun correlate with a higher concentration of essential oils in the rosemary’s leaves, which increases the taste and aroma of rosemary foliage. Rosemary does not grow well in the shade.
  • Potted rosemary does not require any fertilizer. Rosemary has adapted to growing in gritty soils, without much nutrients, and thrives in these conditions. Fertilizer decreases the concentration of essential oils and, therefore, reduces the aroma and flavor of the rosemary’s leaves.
  • Prune rosemary anytime in the Spring up until mid-summer. Prune the top third of growth to stimulate newer growth and create a rounded, bushy appearance that resists adverse weather conditions better.
  • Mature potted rosemary plants can tolerate a light frost but should either be brought indoors in Winter or wrapped in horticultural fleece to protect them from frost. Place rosemary in a sunny window and water every 4-6 weeks to prevent the rosemary from drying out completely.

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