How to Revive Dying Herbs

I love to grow herbs, and I can tell you from experience that most herbs are relatively easy to grow when you know the secret. The secret is that we need to successfully recreate some of the preferred growing conditions of their native environment in our gardens.

The main reason herbs die is 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 them 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, we need to 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.

As there are several common reasons I encounter for dying herbs, I created this table to help you quickly diagnose the problem…

Keep reading for what’s causing your herbs to die back and how to save them…

Why are My Herb’s 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.

Wilting herbs is a problem every gardener has had at some point (myself included!) I have had to revive many herbs from a wilted state and return them to full health, but first, we need to identify the problem…

In my experience, the most common reason for herb wilting is drought stress. This is due to planting in small pots, which have less capacity for soil and, therefore, hold less moisture. Our small pots heat up in the sun quicker, drying the soil and causing herbs to wilt as a sign of stress.

For our herbs that lack a woody structure such as basil, cilantro, parsley and mint, they rely on tugor pressure for structural support to stay upright.

Tugor pressure occurs when the leaves of the herb transpire water vapor, which draws more moisture from the soil to the roots. This creates pressure in the plant cells in the stems of the herbs, keeping the stems rigid so they stand upright. (Do you remember this from school?!)

If the soil at the herb’s roots has too little moisture, they will begin to wilt, a sign of drought stress.

How often we should water our 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 pot’s size, the soil’s capacity to hold moisture, the climate, and weather conditions.

I once had all my herbs mass wilt downwards despite a good watering schedule, good soil, etc. What I learned was that all herbs (even the drought-tolerant Mediterranean herbs) wilt on hot days to conserve moisture during the high afternoon temperatures and recover when the temperature cools in the evening, which is a common survival strategy for all herbs, so don’t panic if this happens to you!

My herbs returned to full health once the temperature cooled after a heat wave.

My Tips for Reviving 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 herb garden thoroughly. I always do this as I’ve found that it is the best way to ensure that there is enough water to effectively infiltrate the soil and reach the roots of the herbs where it is required rather than just moistening the surface of the soil.
• I recommend watering thoroughly as it stimulates the roots to grow down into the soil to access moisture, which increases the herbs’ resilience to hot and dry weather and their 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 than 12 inches, consider a pot the next size up, particularly if your herbs are in a hot and dry climate, to prevent wilting.
• My herbs tend to grow best in 6 hours of morning sun. If possible, move potted herbs into shade to reduce heat stress while they are wilted. When I live in a hot climate (in Southern California), I experimented with several different ways of growing and found that my herbs grew best with the 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 than 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 herbs 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 perfect 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. I tested all the best soil amendments for leafy herbs and found that leaf mold was the best as it has a greater capacity to hold moisture than the other amendments I tried (manure and various other organic materials), which visibly helped my herbs endure heat waves and better then my other herbs that were potted in standard potting soil.
• 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 if you are growing them in a vegetable garden (of course this is less practical for our potted herbs). There may be limited space for a layer of mulch but if your herbs are in a raised bed or allotment 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.

For my potted herbs, I found the most effective treatment is to replant them in much bigger pots with lots of compost and leaf mold and hide them from the afternoon sun.

When I had a vegetable garden, I once used an umbrella to shade my wilted herbs from the afternoon sun, which was an effective way of alleviating the drought stress and helping them revive.

In my experience, my wilted herbs recover from wilting in 2 or 3 days, but sometimes they last longer if there is a heat wave.

(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, pots too small and dry too quickly, and small pots also have less capacity for soil and nutrients, causing a nutrient deficiency.

When I see herbs turning yellow, my experience has taught me to check to see if the soil is too damp…

The most common reason herbs turn yellow is too much moisture around the roots, caused by watering too often, slow-draining soil, or a lack of drainage holes in the base of the pot. Too much water around the roots interferes with the root’s 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. (From experience, root rot is more common with Mediterrenean herbs).

From my years of growing herbs, I have learned that 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).

So we need to remember all our herbs require some direct sunlight. If our 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.

Another classic mistake I see alot of beginner gardeners make is to apply fertilizer too often or in too high concentration which 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 I Revive Yellowing 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 effect. I place all my woody Mediterranean herbs in as much sun as possible (more than 6 hours of sun), and for leafy herbs, ideally, I find a location so that they have 6 hours of morning sun followed by shade or dappled light in the afternoon although I have also grown them in full sun (I find it depends on how hot your climate is).
• 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 than 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 herb’s roots to develop. With greater nutrients available, the herbs can begin to recover from a yellowing appearance if they have been 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 from 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 to bring them back to healthy growth. I must emphasize the importance of wiping the blades with a cloth soaked in disinfectant after every cut to ensure that you do not accidentally transfer any fungal pathogens from diseased roots to otherwise healthy roots. I personally use hand gel.
• 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 from experience, 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 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 of 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 or grit and 70% compost to replicate the drainage conditions of their native range. From my experimentation comparing how well my Mediterranean herbs grow in sand compared to grit, I found grit had sharper drainage and created a better-treated structure around the roots, which reduces the risk of root rot.

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 on 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).

Why Are My Herbs Dying After Transplanting?

If you have bought herbs from a store or garden center or perhaps grown 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. I’ve had this problem myself.

I found out first-hand why this is when I worked in a commercial garden nursery that grew a variety of plants wholesale to various garden centers…

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.

I observed personally that 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.

However, I can assure you that 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.

The steps I took to ensure my herbs adjusted were to plant it in an area of around 6 hours of morning sun (provide some shade in the afternoon to protect it from heat stress whilst it establishes), in good quality compost and water it 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 my herbs revived after 2 weeks as it adjusted to the conditions of my 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?

In my experience, herbs with drooping stems that seem to be falling over under their own weight can happen 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).

My Tips for Reviving Drooping Herbs…

My secret to reviving my herbs with drooping stems and leaves is 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, I prune these herbs to a height of around 8 inches to stimulate lots of new tasty leaves, prevent flowering, and stop the stems from drooping. I find by always trimming my herbs to around 8 inches, I get the best harvest of herbs.
• 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 well draining so avoid planting herbs in clay soils or boggy areas. As we discussed, the woody Mediterranean herbs require their potting soil to be amended 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. I’ve made this mistake myself, and my basil rebounded after a good trim and grew well the rest of the year.
• 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

I get it. Sometimes, you take your eye off the ball, you go on holiday, and your herbs just aren’t your biggest priority! In most cases, you must prune back any leggy growth exceeding 8 inches tall and provide the best conditions for your herbs. It should show signs of recovery after a week or so.

(Read my article, choosing the best pots for herbs).

Key Takeaways:

• The most common reason herbs die is root rot, which occurs when there is too much moisture around the roots caused by overwatering, slow-draining soils, and pots without drainage holes in their bases. Herbs require well-draining soil, and damp soil promotes root rot, causing herbs to turn yellow and die back.
• The main reason Mediterranean herbs die is 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 root’s ability to uptake water and nutrients, causing the herb to die.
• Leafy herbs such as basil, cilantro, mint, and parsley die back after flowering. To prevent leafy herbs from dying, prune them once every three weeks during the Summer so that they remain around 8 inches tall. Pruning promotes the growth of new leaves and increases the herbs’ longevity.
• To revive dying herbs, cut back diseased roots to healthy growth with a sterile pair of pruners. Wipe the blades with disinfectant after every cut to prevent the spreading of fungal pathogens. Replant the herb in a new pot with new soil and locate the plant in partial sun while it recovers.