Mint is one of the hardiest herbs and one that I always recommend for inexperienced gardeners to grow in pots due to its resilience and relative low maintenance.
However occasionally there are problems with mint plants that are often as a result conditions that are contrary to their preferred environment. The most common reasons for mint dying are usually because of:
- Under watering (mint requires consistently moist soil).
- Root rot (boggy soil or pots without drainage can cause mint to turn yellow and droop).
- Mint dying in a pot due to pots or containers that are too small or because of a lack drainage holes in the base so excess water cannot escape.
- Leggy growth with few leaves due to lack of sun or too much fertilizer.
Keep reading for how to implement the solutions to each of these ailments to save your dying mint plant…
Under Watering Mint
- Symptoms. Wilting leaves and stems, often turning brown.
- Causes. Under watering and quick draining soil.
Under watering is the most common reason for mint plants to look as though they are dying.
Mint plants thrive in moist soils and can wilt quickly if the soil dries out and it is can one of the first plants in the garden to wilt in hot climates or during drought.
Therefore mint grows best when it is watered regularly and planted in soil or a potting mix that retains moisture.
Mint does not grow well in sandy or stony soils as they drain too quickly for the roots to draw up moisture.
How to Save Under Watered Mint
Thankfully the solutions to mint wilting are easy to implement.
- Water the mint frequently so that the soil stay moist. It is important to adjust the frequency of your watering to maintain the moisture of the soil. This varies according to the time of year and your climate. In hot climates water once every three days whereas temperate climates may only require one watering per week.
- Plant mint in rich compost. Compost is excellent at holding moisture yet still has a porous structure to allow excess water to drain so that it does not become boggy.
Careful monitoring of the soil moisture by testing it to a finger depth, and adjusting your watering frequency according, ensures that soil does not dry out and dehydrate your mint plant.
Always water mint with a generous soak to encourage the roots to establish properly. Frequent light watering encourages shallow root growth which makes your mint plant more vulnerable to drought.
It is important to acknowledge pots and containers do dry out quicker then soil in garden boarders, particularly if the pot is located in full sun (mint can grow in full sun or partial shade).
The use of mulch can help mint planted in garden boarders retain moisture around the roots.
Compost, leaf mold and well rotted manure are all excellent options as they retain moisture, reduce soil evaporation and improve the soil structure to suit the mint.
(Read my article, how often to water mint plants).
Mint with Root Rot (Yellow Leaves and a Wilted Appearance)
- Symptoms. Mint has turned yellow or brown with a wilting appearance.
- Causes. Over watering, boggy ground or slow draining soils.
If your mint plant has turned yellow and has a drooping appearance then this is most likely due to root rot or a fungal disease pathogen.
Root rot and fungal diseases thrive in soils that are consistently saturated where excess water does not drain away very quickly.
This is in contrast to the mints preferred conditions in which it thrives in consistently moist soil that has a porous texture which allows excess water to drain away so that the roots of your mint plant are not sat in boggy ground.
Root rot can occur because of over watering but is usually because of slow draining soils (such as clay or compacted soils or naturally boggy areas of the garden) and pots without drainage holes in the base.
How to Save Mint with Root Rot
To save mint that us turning yellow because of root rot it is important to:
- Scale back the watering of the mint.
- Transplant the mint to a well draining area of the garden or to a pot.
- Ensure the mint is planted in a pot with drainage holes in the base.
Mint requires consistently moist soil but if the soil is already damp and there is not much evaporation due to cooler weather then this can potentially lead to root rot.
Water the mint so that that the soil is consistently moist but not saturated.
If your soil is compact, has a high clay content or is naturally boggy then transplant the mint to an area of the garden with improved drainage so that the roots of the mint are not in saturated soil.
Alternatively you can plant mint in pots, containers and raised beds which is usually the best option as pots prevent mint from spreading in the garden boarders (which then can do quite aggressively, growing from ‘runner’ roots).
When you are transplanting the mint:
- Inspect the roots. The roots should be white coloured and healthy. If any roots are dark brown and look rotten or diseased, use a pair of pruners to cut back the disease roots to healthy growth.
- Ensure that you clean the blades of the pruners after each snip with disinfectant to prevent spreading fungal pathogens from diseased growth to otherwise healthy growth.
- Plant the mint into new multipurpose compost ensuring the pot has drainage holes in the base.
- Burn the diseased roots of the mint plant and discard the soil as they can both carry the fungus that affect the mint.
Mint does not always recover from root rot but if you cut away the diseased tissue and plant it in a pot with new soil the mint has the best prospect for recovery.
Mint Dying in a Pot
- Symptoms. Mint that is drooping and turning brown or yellow or not growing.
- Causes. Pot size too small, poor soil, root rot due to a lack of drainage holes in the base.
Growing mint in pots and containers allows for good drainage and prevents the mint from spreading and taking over garden boarders (mint can grow out of control if left to its own devices).
However if the mint plants can droop if the pot is too small as mint requires consistently moist soil. In smaller pots the soil dries out quickly which can result in mint plants that wilt and turn brown.
Another common problem is a lack of drainage holes in the base of the pot.
Mint requires moist soil but if the pot does not allow excess water to escape then the soil becomes boggy which promotes the conditions for root rot and fungal disease which turns the foliage yellow or brown.
How to Revive Dying Mint in a Pot
To save your potted mint plant it is important to…
- Plant or transfer the mint to a larger pot of at least 12 inches across to stop the soil drying out too quickly and prevent the mint from wilting.
- Ensure that your pot has drainage holes in the base so the soil does not become boggy.
In a larger pot or container there is a greater capacity for soil and therefore more moisture. A larger pot of at least 12 inches across does not dry out as quickly as small pots, which prevents the mint from wilting, along with a frequent watering schedule.
With more soil, the roots of your mint plant have more room to establish and access the nutrients they require so that the mint produces more foliage and is less vulnerable to disease.
Water the mint as frequently as required to keep the soil moist and the mint should recover from a wilted appearance in a few days.
It is also important to plant mint in pots with drainage holes in the base which allows excess water to escape and prevent root rot.
Avoid using a tray, saucer or anything underneath the pot that might catch the water and cause the soil to become boggy.
Leggy Mint with Sparse Growth
Leggy mint plants with excessive growth that droops over are usually a sign of:
- Not enough light.
- Too much fertilizer.
Mint plants can grow in full sun or partial shade, but if they are in too much shade then the growth can look sparse with fewer leaves and a weak aroma.
Mint without enough light grows leggy as it searches for more sunlight which causes the stems to droop under its own weight.
Additionally too much fertilizer can stimulate excessive growth causes the stems to grow sappy and not as sturdy for structurally supporting the plant.
This can also cause mint to droop, although it is likely to have abundant foliage growth which can have a weaker aroma and taste.
How to Save Leggy Mint
The easiest way to save leggy mint is to locate the mint in a sunnier area, if it is too shaded and the mint should begin to show signs of recovery over the next week.
Avoid using too much fertilizer as this can have a detrimental affect on your mint plant.
Mint often does not require additional fertilizer if it has been planted in rich compost, however if growth is slow then use a half strength fertilizer every 4-6 weeks during the growing season.
For mint plants that are drooping due to a lack of sunlight or too much fertilizer I would recommend tidying up the plant with a good prune. Here’s a YouTube video for a great visual guide on how to prune your mint plants:
- A dying mint plant is usually because of under watering or as a result of mint that is planted in a pot that is too small and therefore has limited moisture and nutrients. If your mint is wilting and turning brown this is likely because of dry soil and under watering.
- Mint plants with yellow leaves and a drooping appearance are dying because of root rot caused by over watering, slow draining soils or pots without good drainage.
- Mint that is leggy and drooping is usually because the mint does not have enough light or because of too much nitrogen due to the use of excessive fertilizer.
- Plant mint in well draining compost and keep the soil consistently moist without being saturated. Ensure potted mint has drainage in the base of the pot or container. Mint prefers full sun or partial shade. Keep mint in these conditions and your mint has the best prospects for recovery.