Rosemary Turning Brown: 7 Causes & Cure

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Rosemary or Salvia Rosmarinus is a shrubby evergreen plant with coniferous leaves and fragile light blue flowers. The needle-like leaves have an intense aroma and a spicy, astringent, bitter taste.

The plant is native to India and the Mediterranean, where it overwinters in gardens. In places with harsh climates, it is grown as an evergreen, perennial plant in containers, protected from frost and low temperatures.

Although rosemary is a hardy and tough plant, its cultivation in pots or outside its natural habitat may be demanding. Namely, it is a plant that needs at least 6 to 8 hours of sunlight a day, all year round, which could be tricky to provide.

Additionally, it is necessary to give a uniform temperature throughout the year, moderate watering, and adequate fertilization. If the conditions in which it grows are not satisfactory, it will not thrive, and one of the most common problems that occur is a change in leaves’ color.

Instead of the intensive dark green color of the leaves’ upper side and silvery gray reverse, the leaves will get an inconspicuous brown color.

Why does my rosemary have brown tips?

Unfavorable growing conditions or inadequate care of rosemary will first manifest through changes in its leaves. Every aspect of cultivation can cause these changes, but here are the most common ones.

1. Dry soil

Although it comes from warm, dry areas, you need to water the rosemary in the pot regularly. When 1/3 of the substrate in the pot dries, it is time for the next watering.

Water it abundantly and make sure to remove the excess water that accumulates in the tray. Rosemaries do not like drought, but they suffer equally if their substrate is too soaked.

2. Nutrient deficiency

Like all other pots, rosemary needs extra nutrition because what it has in the pot is sometimes not enough for healthy growth.

Therefore, feed rosemary from spring to autumn with fertilizer for houseplants dissolved in water at least twice a month. In winter to once a month decrease feeding since the plant rests and gathers strength for new spring growth.

3. Lack of light

Rosemary cultivation is successful only if you can provide it with plenty of light throughout the year. The plant that grows in the shade develops poorly, looks sick, and in the end, can be destroyed. In summer, keep the plant outside in a well-lit place.

In winter, place it on a south window. Or use artificial light at a distance of at least 10-15 inches away from the plant to avoid heat burns.

4. Low temperature

The main factor in growing rosemary is keeping a proper temperature. In summer, this is not a problem. However, during the winter, pay attention that the room temperature does not fall below 32F.

This heat lover reacts quickly and violently to low temperatures, and one of the most common reactions is brown leaves that fall off.

5. Wrong place

If the leaves of your rosemary are brown, the plant may stand on a cold window. It often happens in the spring or fall, when the heating is not yet on.

When the root system catches a cold, especially by frequent watering or watering with cold water, the roots begin to rot, which immediately affects the plant crown.

6. Dry air

When you grow the plant indoors, one of the problems you may face is excessive air drying. The problem is especially pronounced in winter when the moisture level due to heating drops to about 30%.

In such conditions, rosemary will not feel good. It will react by drying the leaves or twisting them, trying to reduce transpiration and moisture loss. Therefore, it is necessary to spray the plant regularly.

In summer, when the water evaporates faster, spraying will be a pleasant relief. In winter, when moisture retention on the leaves could cause fungus, place the plant on a pebble tray to raise the humidity level.

7. Overwatering

Excess water around the root system due to inadequate hydration or heavy soil that retains water for a long time will cause serious problems in the plant’s metabolism.

Excess water destroys chlorophyll, so the leaves first get a pale yellowish color. If nothing is done, the leaves and stems will darken to become brown and mushy, which is a sign that the root is rotting.

How do you revive a dying rosemary plant?

rosemary plant

To save a plant with brown leaves, you first need to determine which of the next causes brought the plant to that condition.

Some of them you could solve by changing the way you nurture the plant. However, the problem of excessive watering is the most dangerous and the hardest to solve. If you see any flabby, brown leaves and stems, you can try the following.

  • Carefully remove the plant from the pot.
  •  Inspect the root and remove any diseased or rotten parts. Keep in mind that the plant cannot survive if you cut more than one-third of the root mass.
  • Clean the root and rinse the root under lukewarm water.
  • Leave the plant in the shade for a few hours for the root to dry.
  • In the meantime, prepare a new container filled with a mixture of equal parts of substrate and perlite or sand.
  • Transplant the plant into a pot and do not water for the first seven days. During this period, keep the plant in light shade, out of direct sunlight.

Can you use rosemary after it turns brown?

By changing the leaf’s color, the plant clearly shows that there has been a disturbance in its metabolism. Color is not the only thing that leaves loss as a result of this disorder. Their characteristic smell and taste also change, so such parts of the plant are not for use.

Why is my rosemary turning yellow?

As described before excess water could cause yellow leaves. The same problem can happen due to insufficient watering. In the absence of water, the plant redistributes the available amount, leaving one part of the leaves without moisture, which causes the leaves to turn yellow and fall off.

If improper watering is not the cause of leaf yellowing, then check the substrate. Rosemary will not thrive in poor soils with low levels of nitrogen, magnesium, or zinc.

Substrates for houseplants as well as regular feeding will solve or prevent this problem. Transplant adult well-developed plants every spring. Or replace the top-worn layer of substrate with fresh ones.

Why does my Rosemary have leaf spots?

Rosemary is a healthy and hardy plant that rarely gets sick, and pests usually avoid its leaves. But resistance does not mean immune, so it can be attacked by fungi, especially if it grows in high humidity conditions.

The disease spreads rapidly, so fungi can completely overwhelm the leaves. However, don’t wait for this to happen and act as soon as you notice the first signs. Remove all diseased leaves. Rosemary tolerates pruning well, and even as you shorten it by two-thirds, it still has a good chance of recovering.

Do not spray the leaves if you see that drops of water stay on them for more than two hours. The moisture level, in this case, is satisfactory, and the plant does not need additional hydration. Do not use fungicides because the leaves, even if they heal after the fungicide, are not usable in the diet.

Mike Smith

I love Gardening and this is my site. Here you will find some really useful plant-related tips and tricks.