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How Fast Does Rosemary Grow? (Explained)

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Last updated on September 26th, 2022 at 08:58 am

Plants differ in how fast they grow. The rate at which a plant grows depends on the type of plant, climatic factors such as sunlight, rain, wind, temperature, soil type, and the presence and absence of other plants and diseases. 

How fast does Rosemary grow? Rosemary is a fast-growing plant that achieves maturity within 12 months if propagated from seeds or within six months from the stem cuttings of already established plants. Its fast growth also depends on suitable soil type, climatic factors, and the absence of pest activities.

Is Rosemary A Fast-Growing Plant?

Rosemary is a fast-growing plant. When propagated by seed, Rosemary takes about 12 months to mature, while six months is sufficient when propagated from stem cutting.

However, propagation is not the only factor that affects how fast it grows. Other factors can directly affect the speed of growth of Rosemary.

These factors include climatic factors such as sunlight, rain, wind and temperature, the soil type, propagation method, disease, and pests. In addition, the horticultural habits of the gardener also affect the growth rate.

These factors are discussed below:

1. Rosemary is a sun-loving plant:

Hence, adequate sunlight is necessary for it to grow fast. Therefore, Rosemary should receive at least six to eight hours of sunlight daily to ensure fast and adequate growth.

2. Water:

Although Rosemary is drought resistant, the availability of water affects how well Rosemary grows. Too much water can cause the root to decay, resulting in death or even stunted growth for some roots that may be viable.

To achieve faster growth, Rosemary should be grown in well-drained soil and watered as needed, especially when the top of the soil is dry to touch.

3. Soil type:

Rosemary prefers well-drained loamy soil with a pH between 6.0 and 7.0. Rosemary would grow slowly in clay soil, especially if it is not well-drained and improved with organic matter.

4. Method of propagation:

Rosemary grown from stem cuttings obtained from established plants will mature quicker than ones sown from seed. The germination rate when propagated from seed is low, and the seeds take a long time to sprout and grow.

5. Disease:

The rate of growth of Rosemary can be adversely affected by plant disease(s). Rosemary is susceptible to both fungal diseases and some bacterial infections.

The common fungal disease that can slow or even cause the death of Rosemary includes root rot, downy mildew, Botrytis blight, and powdery mildew.

If infected with root rot, the rosemary plant would, in most instances, die off or develop stunted growth in some cases.

Bacterial blight is the most common bacterial plant disease of Rosemary. The bacterial disease of Rosemary can commonly affect its growth.

6. Pests:

Rosemary as a herb is susceptible to pests, especially insect pests. Insect pests that usually affect the growth of Rosemary include Mealybugs, Aphids, scale, and spider mites.

They can eat off the plant’s leaves, roots, or stem and are vectors of some diseases that negatively affect Rosemary, thus impeding its growth.

Is Rosemary A Slow-Growing Plant?

Rosemary is not a slow-growing plant, although it takes up to a month for seedlings of Rosemary to grow. Once established, it grows fast and achieves maturity within 12 months, although it is a perennial plant in warm zones.

You can achieve a shorter period to maturity if the plant is grown from stem cuttings, layering, or divisions.

Although not in its nature, you may find your rosemary herb to be growing slowly or worse, even retarding! Trust me; this situation is genuinely alarming, yet if stitched in time, the fatality of the plant will not even come close.

So, to help you improve a slow-growing rosemary herb, I have prepared a guideline right here! You can apply the suggestions below based on the cause of slow growth identified:

1. If grown indoors, you should ensure the sunlight needs of the rosemary plant.

When you grow your Rosemary indoors or are planning on bringing the potted plants indoors, you must allow the plant to acclimatize to its new condition gradually before finally settling it into its final stand.

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You can do this by moving it gradually to a shadier portion of the house to produce better-adapted leaves to the new lighting conditions. It may also be helpful to set a Led light as close as possible to the plant to augment for sunlight.

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2. In a case where the degree of irrigation or water content of the soil has caused your Rosemary to grow slowly, ensure to water the plant regularly.

If the plant is newly established, ensure to water frequently within the first one or two weeks to help it survive. After that, it could be watered when needed.

For plants grown in pots, the irrigation frequency should be increased, especially when the soil is dry to the touch at the pot’s surface. However, as mentioned earlier, take care to avoid too much water harming the plant.

3. When soil is the cause of slow growth, the soil can be improved upon, depending on the type of soil.

For Rosemary grown in clay soil, you should ensure that its ability to drain is improved upon as poorly draining clay soil can result in slow growth or death of the plant if the soil becomes waterlogged.

Improve clay soil for optimum plant growth by adding organic and compost manure with regular tilting to achieve better aeration and recycling of nutrients both inside-out and outside-in.

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As with clay soil, if waterlogged soil is causing slow or stagnant growth, organic fertilizers can be added with regular tilting and creating drainage channels.

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4. If Rosemary is heavily infested with pests or diseased and thus cannot grow as fast as it should, the pests that can cause such disease should be identified and eliminated.

You can combat fungal diseases of Rosemary with an organic fungicide spray or a mixture of baking soda. Prevent root rot from killing the plant by digging up the plants, cutting off the infected roots, and dusting with a fungicide.

When the root rot is extensive, the entire plant should be disposed of.

How Long Does It Take For Rosemary to Grow?

Though a perennial, Rosemary establishes and grows to maturity within a year. Almost after a year of propagation, a healthy plant should be ready for harvest.

As I earlier mentioned, when propagated by seed, Rosemary will take about 12 months to mature. On the other hand, in 6 months, Rosemary propagated from stem cuttings becomes fully established.

As stated earlier, planting the plant in well-draining soil that is watered as needed is vital to prevent many diseases that can adversely slow down or cause the death of Rosemary.

However, horticultural practices such as adequate sunlight, drainage, and protection from pests and diseases are observed to ensure adequate growth within the best time limits.


Rosemary being a fast-growing herb is highly sought after not just for its diverse uses but because it is easy to propagate.

Its speed of growth is quite impressive, and it only slows down when growing requirements are not met.

When grown from seeds, it takes about 12 months to reach maturity and about six months when grown from stem cuttings of already established plants.

It is not too late to propagate this herb, no, because the herb becomes ready for harvest in no time! It is simply the nature of the rosemary herb.


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