Most herbs are relatively easy to grow once you successfully recreate some of their preferred growing conditions.
The main reason for herbs dying is because of root rot which is caused by overwatering, slow draining soil and pots without drainage holes in the base. Herbs require well draining soil and suffer root rot because of excess moisture around the roots which causes herbs to turn yellow, droop and die back.
Some leafy herbs such as basil, cilantro, parsley and mint also die back after flowering so it is important to prune these herbs regularly to stimulate growth and promote a good supply of fresh leaves.
Woody Mediterranean herbs (such as lavender, rosemary, thyme, sage and oregano) are very sensitive to overwatering and require sandy, well draining soil to avoid root rot (read my article how often to water lavender for more).
To revive dying herbs cut any diseased roots back to healthy growth with a sterile pair of pruners and replant the herb in a pot with drainage holes in the base with new, well draining compost. Locate the herb in partial sun whilst it is recovering and water thoroughly.
|Symptoms:||Reason for Herbs Dying:|
|Herbs stems and leaves wilting:||High temperatures, too much sun, soil that drains too quickly, underwatering and smaller pots containing less soil, therefore less moisture which dry out too quickly.|
|Herbs turning yellow:||Over watering, boggy soils, pots without drainage holes in the base causing root rot. Too much nitrogen fertilizer or too little nutrients in the soil can turn leaves yellow as can a lack of sun.|
|Herbs dying after being in the store or after transplanting:||Transplant shock, caused by the contrast in conditions from where the herb was cultivated to the conditions of your garden. A sudden change in light, temperature, watering and soil conditions can all cause your herb to die back. A significant disturbance to the roots can also cause herbs to die back.|
|Herbs drooping:||Herbs can droop if they are not pruned often enough, due to too much nutrients in the soil or because of a lack of good soil drainage which can cause root rot.|
Keep reading for whats causing your herbs to die back and how to save them…
Herbs Leaves and Stems Wilting
- Symptoms: Herbs leaves or stems wilting, despite frequent watering.
- Causes: High temperatures, intense sun, small pots, soil drains too quickly, temporary wilting due to heat.
The most common reasons for herbs wilting is because of drought stress due to planting in small pots which have less capacity for soil and therefore hold less moisture. Small pots heat up in the sun quicker which dries the soil and causes herbs to wilt as a sign of stress.
Herbs that lack a woody structure such as basil, cilantro, parsley and mint, rely on tugor pressure for structural support to stay upright.
Tugor pressure is when the leaves of the herb transpires water vapor, which causes more moisture from the soil to be drawn up from the roots. This creates and pressure in the plant cells in the stems of the herbs which keeps the stems rigid so they stand upright.
If there is too little moisture in the soil at the roots of the herb then they begin to wilt as a sign of drought stress.
How often you should water your herbs to prevent wilting depends less on a specific schedule and more on how quickly the soil dries out which can vary according to the size of the pot, the capacity of the soil to hold moisture, the climate and weather conditions.
Herbs may also temporarily wilt on hot days as a method of conserving moisture during the high temperatures of the afternoon and recover when the temperature cools in the evening and which is a common survival strategy for all herbs.
How to Revive Wilting Herbs
- Always water your potted herbs with a generous soak so that excess water drains from the drainage holes in the base of the pot or so that you have watered your herbs garden thoroughly. This ensures that there is enough water to effectively infiltrate the soil and reach the roots of the herbs where it is required, rather then just moistening the surface of the soil.
- Watering thoroughly also stimulates the roots to grow down into the soil to access the moisture which increases the herbs resilience to hot and dry weather and increases the roots access to nutrients.
- Consider transplanting your herbs in a larger pot. Larger pots contain more soil and therefore more moisture so they do not dry out as quickly. If your pot is smaller then 12 inches then consider a pot the next size up, particularly if your herbs are in a hot and dry climate to prevent wilting.
- Herbs tend to grow best in 6 hours of morning sun. Move potted herbs into shade if possible to reduce heat stress whilst they are in a wilted state. In hot climates or at hot times of the year, herbs grow best with morning sun followed by shade in the afternoon to mitigate wilting from excessively high temperatures.
- Mediterranean herbs (such as lavender, rosemary, thyme, sage and oregano) tend to tolerate heat and sun without wilting better then leafy herbs (such as basil, mint, parsley and cilantro).
- Ensure that your soil or potting soil retains moisture if you are growing a non woody, leafy herb such as basil, cilantro or parsley (the woody Mediterranean herbs such as thyme and rosemary require dry, well draining soil amended with sand).
- Leafy herbs require moist, yet well draining soil so compost or leaf mold is prefect as it holds moisture yet allows excess water to drain away which prevents root rot. If planting leaf herbs in a vegetable garden amend the soil with lots of compost before planting.
- Use a mulch after watering. A layer of added compost or leaf mold is a great way to conserve moisture to help revive wilted herbs. There may be limited space for a layer of mulch but if your herbs are in a raised bed then apply a 1 inch layer of compost on the soil to prevent the soil drying so quickly. Apply the mulch after watering your herbs thoroughly to efficiently conserve moisture and keep the roots cool in hot weather.
(Read my article on the best potting soil for herbs to learn how to create the best potting mixes for both leafy herbs and Mediterranean herbs).
Why are My Herbs Turning Yellow?
- Symptoms: Leaves of the herbs turning yellow with possible wilting or drooping stems.
- Causes: Overwatering or slow draining soils, pots without drainage holes in the base, not enough moisture, poor soil or too much nitrogen, not enough direct sunlight, pot is too small and dries too quickly, small pots also have less capacity for soil and nutrients, causing a nutrient deficiency.
The most common reason for herbs turning yellow because of too much moisture around the roots caused by watering too often, slow draining soil or because of a lack of drainage holes in the base of the pot. Too much water around the roots of herbs interferes with the roots ability to uptake water and nutrients which causes the leaves to turn yellow.
If the soil is saturated this also promotes the conditions for fungal diseases such as Phytophthora root rot to thrive which causes the leaves of herbs to turn yellow with a drooping appearance and causes the plant to die back.
Yellow leaves are also a sign of stress because not enough sunlight, too much nitrogen or not enough nutrients in the soil causing a nutrient deficiency.
Most leafy herbs prefer morning sun followed by afternoon shade in hot and dry climates to heat stress and excess water loss at the hottest time of the day (woody Mediterranean herbs prefer full sun and can tolerate heat).
If your herbs are in too much shade they can grow tall and turn leggy as they look for more light and turn yellow as a sign of stress.
Applying fertilizer too often or in too high concentration can causes herbs to turn yellow and cause floppy growth with a weaker aroma and poor flavor, however herbs also turn yellow due to a lack of nutrients in the soil if the soil is particularly poor.
How to Revive Yellow Herbs
- Ensure that your herbs are in a location with enough sunlight. Mediterranean herbs in particular prefer full sun and cannot grow well in partial shade with yellow leaves being a common side affect. Locate woody Mediterranean herbs in as much sun as possible (more then 6 hours of sun) and for leafy herbs, ideally find a location so that they have 6 hours of morning sun followed by shade or dappled light in the afternoon.
- It is essential that all herbs are planted in soil that is well draining and that the pot has drainage holes to allow excess water to escape freely from the base of the pot. If the soil is saturated then the roots cannot uptake nutrients and the herb leaves turn yellow.
- Replant the herbs in a larger pot, if their current pot is smaller then 12 inches across or particularly shallow. A larger pot has more capacity for soil which means it can hold more moisture, if your herbs are suffering drought stress to mitigate the pot drying out as quickly in the sun. A larger pot with more potting soil also has the capacity for more nutrients and room for the herbs roots to develop. With greater nutrients available, the herbs can begin to recover from a yellowing appearance if it has being suffering from a deficit of nutrients due to being pot bound.
How to save yellow herbs with root rot…
- If you suspect the herbs have root rot (from damp soils) inspect the roots. Healthy roots are light brown or even white in color and feel firm and healthy with no bad smell. Herbs suffering root rot have mushy roots that look rotten and diseased and exude a foul smell.
- If the herb still has some healthy roots remaining then cut off the diseased roots with a sterile pair or pruners back to healthy growth. Wipe the blades with a cloth soaked in disinfectant after every cut to ensure that you do not accidentally transfer any fungal pathogens from diseased root to otherwise healthy root.
- Replant the herb in new compost ideally in a new pot as both the compost and pot can harbor the fungal pathogen that is responsible for root rot. This gives the herb a chance of surviving, however if the roots are mostly or all rotten then it can be too difficult to save the plant.
- Always plant herbs in pots with drainage holes in the base to ensure good drainage. For the leafy herbs such as basil, cilantro, mint and parsley, good compost provides the optimal balance of drainage, yet retains enough moisture so that the herbs do not suffer from dehydration. Replanting leafy herbs into new compost or potting soil can save the herbs by providing the right amount of moisture in the soil with good drainage as slow draining soil is often the cause for dying leafy herbs.
- Mediterranean herbs such as lavender, rosemary and thyme require sharp drainage to prevent root rot which turns the leaves yellow. If your Mediterranean herbs are turning yellow replant them in pots with a potting mix that is at least 30% sand to 70% compost to replicate the drainage conditions of their native range.
Watch the video below for how to create the optimal potting mix for all Mediterranean herbs.
(As Mediterranean herbs are particularly sensitive to overwatering which causes them to turn yellow and die back, I wrote some articles specific to each herb, so read my articles how to revive lavender, rosemary, thyme, sage and oregano for more specific advice on saving these herbs).
(For more information on watering, read my article, how often to water herbs).
Herbs Dying After Transplanting
If you have bought herbs from a store or garden center or perhaps grow basil from seed indoors on a window sill the herb often droops or looks unhealthy after transplanting it into a new pot or transferring the herb outdoors.
When the herb is grown commercially for sale in a store, it is cultivated at scale in the optimal conditions of a commercial green house with the right amount of sun, controlled temperature, specific watering and soil conditions as well as the right amount of air flow.
The herbs, grown from seeds or cuttings then become accustomed to a very specific set of controlled conditions and suffers shock due to a contrast in temperature, watering, soil and light conditions when you bring it home from the store or plant it in your garden.
The shock due to the contrast in conditions is often temporary as the root system of the herb establish in the new soil and the plant adjusts to the different set of conditions.
As long as the herb is planted in an area of around 6 hours of morning sun (provide some shade in the afternoon to protect it from heat stress whist it establishes), in good quality compost and watered regularly if it is a leafy herb (such as basil) rather then a woody Mediterranean herb such as rosemary which requires less water (read my article how to water rosemary to learn more) then the herb should revive after it has adjusted to the conditions of your garden.
For leafy herbs such as cilantro, basil and mint it is important that the soil is consistently moist as larger surface area of the leaves can lose a lot of water as it takes time for their roots to establish so that they can draw up water which leaves them vulnerable to drought in the short term.
If the herb is already quite leggy and has completely drooped over then I recommend pruning it around 8 inches which stimulates new, hardier growth.
Why are My Herbs Drooping?
Herbs with drooping stems that seem to be falling over under their own weight can be for several reasons:
- Too much fertilizer. Almost all herbs do not benefit from the use of fertilizer as it can promote excess leaf growth which decreases the concentration of essential oils in the leaves, thus decreasing the aroma and taste of the herbs. The nitrogen in the fertilizer can weaken the stems of the herbs causing them to droop over. Mediterranean herbs in particular are adapted to grow in sandy soils that are relatively low in nutrients so they tend to suffer the most with applications of unnecessary fertilizer.
- Pots and containers without drainage holes in the base and overwatering. Herbs can droop in response to too much water around the roots (which also turns them yellow or brown). Drooping can be the first sign of stress from overwatering but it can also be a symptom of root rot if the herb’s roots are in saturated soil.
- Lack of pruning. The leafy non Mediterranean herbs require regular pruning to stay looking neat and to prevent flowering (which impairs the flavor of the leaves). If the herbs are not pruned every 3 or 4 weeks during the height of the growing season then they grow leggy and droop over (note that woody Mediterranean herbs only require pruning once a year at the start of Spring or late Fall).
How to Revive Drooping Herbs
To revive herbs with drooping stems and leaves, it is important to emulate their optimal growing conditions and prune the herbs regularly.
- Leafy herbs such as basil, cilantro, mint and parsley grow quickly during the Summer and can require pruning once every three weeks to prevent them from growing, tall, leggy and drooping under their own weight. Ideally prune these herbs to a height of around 8 inches to stimulate lots of new tasty leaves, prevent flowering and to stop the stems from drooping.
- Ensure your herbs are planted in pots with drainage holes in the base to allow excess water to escape, to avoid promoting the conditions for root rot and fungal disease. Leafy non Mediterranean herbs grow best in soil that is moist yet well draining so avoid planting herbs in clay soils or boggy areas. The woody Mediterranean herbs require their potting soil amending with grit, sand or perlite to replicate their native gritty soil conditions and to prevent root rot.
- Avoid using fertilizer on your herbs. All herbs can attain enough nutrients from good soil or compost without the need for additional fertilizers which can reduce the flavor and aroma of your herbs. If your herbs are drooping after applying fertilizer, cut the stems back to around 8 inches to stimulate new growth.
- Place your herbs in morning sun and water as frequently as required so that the soil is moist but not saturated if it is a non Mediterranean woody herb. Water Mediterranean herbs (which are adapted to tolerate drought) around once every 2 weeks
Prune back any leggy growth that exceeds 8 inches tall and provide the best conditions for your herbs and it should show signs of recovery after a week or so.
(Read my article, choosing the best pots for herbs).
- The most common reason for herbs dying is because of root rot due to too much moisture around the roots caused by overwatering, slow draining soils and pots without drainage holes in their base. Herbs require well draining soil and damp soil promotes root rot causing herbs to turn yellow and die back.
- The main reason for Mediterranean herbs dying is because of overwatering and saturated soil. Mediterranean herbs require very sharp soil drainage and grow best in soil amended with sand, grit or perlite. Too much moisture interferes with the roots ability to uptake water and nutrients causing the herb to die.
- Leafy herbs such as basil, cilantro, mint and parsley die back after flowering. Prevent leafy herbs dying by pruning your herbs once every 3 weeks during the Summer so that they remain at a height of around 8 inches tall. Pruning promotes the growth of new leaves and increases the herbs longevity.
- To revive dying herbs, cut back and diseased roots back to healthy growth with a sterile pair of pruners. Wipe the blades with disinfectant after every cut to prevent spreading fungal pathogens and replant the herb in a new pot with new soil and locate the plant in partial sun whilst it recovers.