The growth of rosemary is very good in pots because of the favorable drainage conditions. If however, your rosemary in a pot has begun to dry out then it is usually a result of excessive water around the roots, rather than inadequate irrigation.
The reason that rosemary in pots is drying out is typically due to fungal or root rot because the soil is too moist, rather than under irrigation (rosemary requires a well-drained soil) which results in the rosemary to wilt and develop a dry appearance.
Causes of Potted Rosemary Drying Out
The herb rosemary is that is native in Southern France, where it thrives in the Mediterranean climate of scorching sunshine and sandy, well-draining soils, and frequent rain.
To ensure that potted rosemary thrives the soil around the roots should to dry out between periods of watering, mimicking the conditions that grow in the Mediterranean.
The signs of fungal and root rot disease include:
- Dryed out appearance
- The stems and leaves are turning brown.
- An overall drooping appearance
It could sound contradictory that a pot of rosemary appears dry, due to excessive water, but it is true that rosemary is sensitive to excessive watering and prefers soils with good drainage that don’t retain water.
It is important to note that excessive watering isn’t the only thing that can result in excessive moisture around roots, which can cause root rot. Other risk factors include:
- The rosemary plant should be planted in a moist compost mix that is not altered with grit or sand to aid in drainage.
- Use of a pot that is not equipped with drainage holes in its base (or using drip tray).
It’s easy to misinterpret the appearance of a potted rosemary like it’s drying out, as plants that require more water. Gardeners may then increase the amount of the amount of water they use, which can cause more problems and can worsen the conditions that cause root decay.
Rosemary is a drought-resistant flower (when established) therefore it doesn’t frequently suffer stress because of the absence of water.
If the pot isn’t big enough, the pot will heat up in the sun and then dry out before the roots of the rosemary get the chance to absorb water.
A rosemary that is dehydrated, however, tends to not appear dry, but instead droops slightly in appearance. It will respond nicely to irrigation.
Plant the rosemary in a large pot, about 12-16 inches in diameter, to ensure there is enough room enough for roots grow and draw in moisture as needed.
(Read my article on the best way to bring back the dead rosemary plant).
Pots Without Drainage and Drip Trays
One of the main reasons why the soil is too wet for the rosemary roots is that the rosemary is placed in a pot that has been…
- There are no drainage holes in the base.
- The purpose of drip tray is to collect the water that drips from the bottom of the pot.
The roots of rosemary prefer soil to be dry in between watering sessions and, therefore, if the rosemary is placed in a decorative pot with no drainage the pot will begin to collect water, and the soil will become saturated.
If you’re cultivating rosemary in your home and you use drip tray to collect the water that may drip out from the bottom of the pot following watering, this will have the similar effect to planting the rosemary inside a planter with no drainage holes.
Even a tiny amount of water at the base of the drip tray, it can stop the soil from drying correctly, which could lead to damp soil, and also increase the chance of fungal or root rot disease that turns rosemary dark brown, giving it that dry, brittle look.
To stop this to happen:
- Make sure to plant your rosemary in a pot that has drainage holes in the base (even when you need to make holes with the aid of a drill) to ensure that water is able to drain away.
- Do not use drip tray to collect the excess water. When the container is inside and you’re worried about water spilling onto the window sill, put a towel underneath the pot after watering it for several hours until the excess water is drained out of the pot, thereby avoiding water damaging furniture.
Use a Well Draining Potting Mix for Rosemary
One of the most effective ways to protect rosemary from the effects of fungal disease that results in the rosemary having dry and brittle appearance is to supply the rosemary plant with the ideal soil mix.
The rosemary plant is hardy that is able to thrive in neutral, acidic as well as acidic soils. It is important to ensure that your soil properly draining.
The rose is a favorite on the slopes and in coastal areas within The South of France where it thrives in stony or sandy soils that have moderate to low nutrients and drain well.
It is in these environments that rosemary thrives in terms of overall health of the plant as well as the scent and strong flavor that the leaves have.
Pots already have some favorable drainage qualities (similar to hillsides in the rosemary’s native habitat) however it is essential to replicate your sandy soil with some garden sand, grit or perlite to the mix to ensure that the soil is well-drained and doesn’t retain excessive amounts of water or nutrients.
Add about 20 percent sand or grit the 80% of compost or potting soil to the pot. Make sure you are using the standard multi-purpose compost that is not enriched with water retaining agents or fertilizer since this is in opposition to the ideal soil conditions.
The addition of sand or grit to the mix of potting soil ensures drainage rapidly with a porous surface that lets the roots grow and to allow for the root’s respiration.
With a well-draining mix of potting soil, the roots will remain dry between periods of watering , which decreases the risk of root rot causing the rosemary to develop dry appearance.
Over Watering Rosemary in Pots
Because of its Mediterranean roots The rosemary plant is drought-resistant once established. They only require irrigation once every two weeks and maybe once per week during hot weather.
If you water the rosemary excessively (whether it is in a pot or the garden) your soil is likely to become constantly damp around the roots that can cause root fungal or bacterial disease which causes rosemary to develop a dry appearance.
Because of its tolerance to dryness and of water sensitivities, more issues are triggered due to over-watering rosemary than under watering.
Pots have favorable drainage conditions that replicate the drainage conditions found on the hillsides that are home to rosemary throughout Southern France.
It is crucial that you plant the rosemary inside a container that is approximately 12-16 inches wide because smaller pots can heat up too fast in the scorching sunlight and dry out too fast so that the roots cannot absorb the water efficiently.
The only reason rosemary is likely to be affected by under-watering occurs when the container isn’t big enough and is made of plastic or metal (which is able to conduct heat more efficiently than clay or Terracotta).
If the younger growth of the rosemary is falling, it is a sign it isn’t getting enough water, but this happens the rosemary that is in small pots or plants in the house which have been neglected, and not pots outside.
- Potted rosemary can appear like it’s dry, but it is an agro-ecological plant, therefore the appearance of dried out can be an indication of stress caused by excessive watering and then inadequate watering.
- The dry appearance of rosemary can be an indication of fungal root rot, or root disease that thrives in moist soils.
- Rosemary likes soil that is dry in between watering, so the pot needs to have adequate drainage to avoid damp soil. Add sand or grit for better drainage. Water only every two weeks to avoid fungal and root rot that causes dry appearance.