Because of the good drainage, rosemary can flourish when grown in containers. However, excessive moisture around the roots is more likely to be the cause of your potted rosemary’s drying out than insufficient watering.
Rather than being underwatered (rosemary needs well-draining soil), root rot or fungal disease are the typical causes of potted rosemary drying out. This causes the rosemary to wilt and appear dried out.
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Causes of Potted Rosemary Drying Out
A native of Southern France, rosemary flourishes in the region’s Mediterranean climate with hot, dry days, sandy soils, and infrequent rainfall.
The soil around the roots of potted rosemary must be allowed to partially dry out between waterings in order to mimic the Mediterranean climate.
The fungus “Botrytis” or root rot can strike rosemary quickly if the soil around the roots is consistently wet.
Root rot and fungal disease have the following symptoms:
- a parched appearance
- stalks and leaves are turning brown
- a general look of drooping
The fact that a potted rosemary plant looks to be drying up due to excessive watering may seem counterintuitive, but rosemary is sensitive to overwatering and likes well-draining soils that do not retain water.
It should be mentioned that there are other factors besides overwatering that can result in excessive moisture around the roots and root rot. Other danger signs include:
- To promote drainage, plant the rosemary in a rich compost soil mixture that retains moisture without the addition of sand or grit.
- the utilization of containers without base drainage holes (or using a drip tray).
A rosemary plant in a pot that appears to be drying out can easily be mistaken for a plant that needs more water. Then, gardeners might increase watering, which aggravates the circumstances that lead to root rot.
Rosemary does not frequently experience stress from a lack of irrigation because it is a drought-resistant plant (once established).
The rosemary pot, on the other hand, can heat up in direct sunlight and dry up before the rosemary’s roots have a chance to absorb water if it is too small.
However, a dehydrated rosemary will react well to watering and will not appear to be completely dried up.
In order to give the roots room to spread out and absorb moisture as needed, rosemary should be planted in a pot that is at least 12 to 16 inches across.
(Read my essay on how to save a rosemary plant from extinction.)
Pots Without Drainage and Drip Trays
- without a base with drainage holes.
- the use of a drip tray to collect water that leaks from the pot’s base.
If rosemary is planted in a decorative pot without enough drainage, the container will accumulate water, resulting in saturated soil. Rosemary roots prefer the soil to remain fairly dry between bouts of watering.
This will quickly result in root rot, which causes the rosemary plant to appear to be drying out and render the leaves and stems brown with a drooping appearance.
It has the same result as planting the rosemary in a container without drainage holes if you are growing rosemary indoors and using a drip tray to catch any extra water that may fall out of the base of the pot after watering.
If there is even a small amount of water in the drip tray’s bottom, the soil won’t be able to dry out correctly, which increases the risk of damp soil and root rot or fungal disease, which turns the rosemary brown and gives it its dried-out, brittle appearance.
To stop this from occurring:
- To allow extra water to drain, always plant rosemary in a container with drainage holes on the bottom (even if you have to drill them).
- Don’t use a drip tray to collect extra water. Place a paper towel under the pot after watering for a few hours until the excess water has drained from the pot to prevent water damage to furnishings if the plant is indoors and you are worried about water overflowing on your window sill.
Over Watering Rosemary in Pots
Because of its ancestry in the Mediterranean, rosemary plants are drought tolerant once they are established and only need watering every two weeks, or even less frequently in hot weather.
The soil will be continually damp around the roots of rosemary if it is watered too frequently (whether it is in a pot or in garden soil), which leads to root rot or a fungus that gives the rosemary a dried-out appearance.
Due of its drought tolerance and water sensitivity, rosemary is more susceptible to problems from overwatering than from underwatering.
In fact, the drainage conditions in pots closely resemble those on the Southern French hillsides where rosemary grows.
However, it is crucial to plant rosemary in a container that is around 12–16 inches across because smaller containers heat up and dry out too rapidly in the hot sun, making it difficult for the roots to to absorb water.
The only circumstances in which rosemary frequently experiences underwatering are when the pot is too tiny, composed of metal or plastic, and (which conducts heat more effectively then materials such as clay or terracotta).
If the rosemary’s younger growth is drooping, it may not be getting enough water. However, this only happens to rosemary in small pots or houseplants that have been neglected entirely, not pots that are outside.
Use a Well Draining Potting Mix for Rosemary
Rosemary is a resilient plant that may thrive on soils that are neutral, acidic, or alkaline. However, having well-draining soil is especially crucial.
Rosemary grows well on sandy or stony soils with low to medium nutrients and good drainage on hillsides and by coastal areas in the South of France.
In terms of the health of the plant, as well as the perfume and robust flavor of the leaves, rosemary thrives in these soil conditions.
It is essential to replicate the sandy soil by adding some horticultural sand, grit, or perlite to the potting mix in order to ensure that the soil is well draining and does not retain too much moisture or nutrients. Pots already have some favorable drainage characteristics (similar to the hillsides of rosemary’s native environment).
To 80% potting soil or compost, add around 20% sand or grit. Use a basic multi-purpose compost without moisture holding agents or additional fertilizer to avoid violating the ideal soil conditions.
By including sand or grit in the potting mix, you can make the soil fast drain and have a porous texture that promotes root respiration and root establishment.
A well-draining potting mix allows the roots to remain dry in between waterings, lowering the risk of root rot, which gives rosemary a dried-out appearance.
- Although rosemary is a drought-resistant plant, it may appear to be drying out in a pot. This dried-out appearance is usually an indication of stress brought on by overwatering followed by underwatering.
- The fact that rosemary appears dried out is actually a sign of root rot or a fungal disease, both of which prefer moist soils.
- Since rosemary enjoys dry soil in between waterings, the pot’s drainage system must be effective to keep the soil from becoming soggy. To increase drainage, amend the soil with sand or grit. Water plants only once every two weeks to avoid root rot and fungus, which give them a dried-out appearance.