Thyme Plant Dying? (How to Revive it)


How to revive a dying thyme plant

Thyme plants are low-maintenance perennial herbs that are native to the Mediterranean region of Europe and they are adapted to the growing conditions of the Mediterranean.

Thyme is a relatively short-lived herb and can produce leaves for culinary use for around 5 to 6 years if the plant is cared for properly.

To revive thyme plants it is important to recreate some of the growing conditions of their native Mediterranean environment with an emphasis on watering, full sun and soil conditions.

Whilst some of the conditions of the Mediterranean are required to grow thyme it is a cold hardy plant that can grow in many climates with some adjustments to the conditions.

If your thyme plant looks as though it is dying there are several ways to revive it but first, it is important to understand what is causing the plant to look unwell and in need of reviving

Identity why does the thyme plant need reviving

The most common reasons for thyme dying are:

  • Thyme has root rot or fungal disease due to consistently damp soil.
  • Thyme that is drooping and turning yellow because of damp soils or excess nitrogen in the soil due to additional fertilizer.
  • Thyme plant that is turning brown, dry and dying back.
  • Slow growth of leaves and foliage because of a lack of sun or nutrients.
  • Drooping or slow-growing thyme due to small pots or containers or a lack of drainage holes in the base of the pot.
  • Thyme plant that requires reviving after Winter.

Keep reading for how to solve these problems so that your thyme plant revives and produces new leaves with a strong aroma and pronounced flavour…

Thyme Plant with Root Rot

  • Symptoms. The thyme plant has a wilted or drooping appearance with leaves that are turning yellow or perhaps brown.
  • Causes. Watering the thyme too frequently, slow draining or boggy soils that retain too much water, and high humidity due to planting in close proximity.

Thyme plants grow naturally in the Mediterranean region of Europe where they are adapted to thrive in full sun, infrequent rainfall or watering, well-draining sandy soils and ideally in areas with some airflow to reduce humidity.

Therefore thyme plants have adapted to become drought resistant and require dry, well-draining soil conditions rather than rich soil or compost that is consistently moist as the roots are susceptible to root rot and fungal disease in damp soils.

When established and planted in appropriate soil (amended with sand for better drainage), thyme plants only require watering once every two weeks in most climates and watering once a week during hot weather if planted in pots.

More problems occur when growing thyme due to overwatering rather than underwatering because of their tolerance to drought and the root’s sensitivity to damp soils.

How to Revive a Dying Thyme Plant with Root Rot

  • If your thyme is showing symptoms of root rot then it is imperative to scale back the watering to once every two weeks to allow the soil to dry out somewhat between bouts of watering.
  • Thyme prefers dryer soil so remove anything that retains moisture such as compost, leaf mould or any other type of rich organic mulch.
  • Carefully lever the thyme plant out of the ground with a fork and inspect the roots. If any of the roots look brown, soft or rotten snip back the diseased portion of the root back to healthy growth with a sterile pair of pruners (wipe the blades with a cloth soaked in alcohol disinfectant to prevent spreading any fungus to otherwise healthy growth.
  • Replant the thyme (ideally in a pot) with new soil that has been amended with at least 30% horticultural sand or grit and 70% multi-purpose compost. Discard the old potting soil as this is host to the fungal pathogen that is causing the roots to rot. Treat garden soil with an organic fungicide to kill the fungal disease.

Thyme plants tend to grow well in pots due to their favourable drainage conditions and it is a lot easier to control the soil profile (by adding sand) to improve the drainage when compared with amending garden soil.

Over watering is one of the most common mistakes when growing Mediterranean herbs so it is important to water your thyme plant appropriately for the climate and conditions of your garden.

Watering once every two weeks is appropriate in most cases however you should adjust the frequency of your watering so that the soil around the thyme becomes somewhat dry between bouts of watering.

Amending the soil with sand or grit helps to replicate the well-draining and low to medium fertility soil conditions in which thyme thrive and exude their strongest aroma and most pronounced flavour of the leaves as well as more flowers on display.

Plant thyme around 2-3 feet apart for optimal airflow so each plant is not competing for space, sunlight and air can circulate rather than create a humid micro-climate with plants that are planted too close together.

Follow these steps and ensure your thyme plant is located in full sun and the thyme should begin to show signs of recovery in around 3 weeks or so.

Thyme plant
How to revive thyme plants

Thyme Plants Turning Yellow and Wilting

  • Symptoms. The leaves of the thyme plant are turn yellow, with a wilting appearance.
  • Causes. Damp soils or excess nitrogen because of fertilizers.

Thyme plants are adapted to living in low to medium fertility sandy soil in their Mediterranean environment.

If the soil is rich in nutrients or perhaps there have been applications of fertilizer, there is likely a high concentration of nitrogen in the soil.

Excess nitrogen causes the thyme plant to grow leggy, droop or wilt and the aroma and flavour of the leaves are not as pronounced which has a big effect if you are growing thyme for culinary use.

Yellow foliage and wilting appearance are also common symptoms of root rot as described in the first part of the article so ensure that you allow the soil to dry out between bouts of watering and plant (or transplant) thyme into well-draining soil.

If the soil is consistently moist due to frequent watering follow the steps for reviving thyme with root rot.

Revive with Yellow Leaves with a Wilting Appearance

  • If you have been applying fertilizer to thyme then you should stop as this promotes excess foliage growth with a weaker aroma and flavour.
  • Ideally, transfer the thyme plant from the garden soil or the pot to a new pot or area of the garden and amend the soil with 30% sand or gravel (by volume of the pot or in the planting area) to improve drainage and balance the nutrient profile of the soil.
  • Prune back the leggy, or wilting growth of the thyme to a rounded appearance (do not cut back into woody growth as this is not grow back particularly well).
  • Care for thyme by locating the plant in full sun, and only water the plant when the soil has had a chance to dry out somewhat between bouts of watering and the thyme should begin to revive.

Yellow leaves for most plants often indicate root rot, too much nitrogen and even not enough nitrogen.

Thyme plants have adapted to arid conditions in the Mediterranean with sandy soils that do not retain much moisture with a low nutrient density.

Therefore the reason they commonly turn yellow is because of too much nitrogen fertilizer or damp soils rather than a nutrient deficit in the soil.

Whilst both of these problems are due to different causes, the treatment is similar.

Amend the soil with around 30% horticultural sand or grit to 70% multipurpose compost to provide the optimal soil mix for thyme plants to thrive and produce leaves with the strongest concentration of essential oils for a more pronounced flavour.

Adding sand and grit to the soil recreates the well-draining, low to medium fertility sandy soil conditions of their native Mediterranean, where thyme plants thrive.

Prune back any leggy growth of the thyme, as the excess growth can sap the energy of the plant and the leggy or wilting growth is often more susceptible to disease.

Trim back around a third of the top growth with a pair of pruners to keep the plant nice and tidy. Thyme is resilient and can be pruned as and when you require the herb for cooking or you can trim it back towards the end of the growing season.

Pruning is very easy and similar to pruning other Mediterranean herbs (such as rosemary or lavender) however it is important to avoid cutting it back too harshly as cutting back to the woody part of the plant can limit the growth as the older wood does not produce many new shoots or leaves.

Here is a YouTube video for a visual guide on how to prune thyme:

Thyme Turning Brown and Dry

  • Symptoms. Thyme plant with leaves turning brown and dried up with sparse growth.
  • Causes. Severe frost, natural dieback (thyme only lives around 5-6 years) lack of sun, or fungal disease.

Thyme is a perennial herb that often only lives for 5 or 6 years even with good care.

After 3 years thyme plants growth tends to slow down and produce fewer leaves with a weak aroma and inferior flavour compared to younger thyme plants.

Thyme leaves tend to begin to turn brown with a dried-up appearance after 5 years naturally, which is why taking cuttings for propagation is very popular so you can maintain a supply of thyme with little maintenance and at a low cost.

Thyme is considered cold hardy and can survive a cold Winter with frost (hardy in USDA zones 5-9), however, a severe frost or perhaps a late Spring frost (when new growth is emerging) can cause the plant to turn brown.

(Read my article to learn how to solve thyme plants turning brown).

Thyme also thrives in full sun, so if the plant is located in an area with less than 6 hours of sun per day then brown foliage may be a sign of stress due to lack of direct light or perhaps water sensitivity due to slow draining soils or overwatering.

Revive Thyme that is Drying out

  • Thyme is relatively short lived as with a lot of Mediterranean herbs. Take cuttings for propagation for more thyme plants as it is cost-effective and has a much higher success rate than growing thyme from seed.
  • If thyme has suffered because of frost, then cut away any damaged growth in the Spring when the temperature is warmer, which stimulates new healthy growth. Do not cut away the growth if there is a threat of frost as the wound from the cut can be susceptible to further frost damage.
  • Always plant thyme in an area with full sun. Thyme does not live for very long when grown in partial shade so locate the pot or container in a sunny area or transplant your thyme to an area of the garden with more sun and perhaps cut back any overhead vegetation that may be casting shade.

Propagating thyme plants is very simple, with a high success rate and one plant can supply many more thyme plants for next year. Watch this YouTube video for an easy guide, how to successfully propagate thyme from cuttings:

In addition, the plant must have optimal growing conditions to avoid drying dry and brown such as:

  • Locating it in full sun.
  • Allow the soil to dry between bouts of watering (typically water pots once per week and only water thyme planted in garden soil once every 2 weeks during drought).
  • Good airflow by planting each thyme, around 2-3 feet apart if in a humid climate.
  • Well-draining, sandy soil that does not retain too much moisture around the roots.

The more you adjust the conditions to replicate some of the thyme plant native Mediterranean conditions, the healthier and more resilient thyme will be, however, thyme does not require a Mediterranean climate and can thrive in temperate climates with higher rainfall as long as the soil is well draining so the roots can dry out properly.

Thyme Plant not Growing

  • Symptoms. Thyme plants with little to no growth and an unhealthy appearance.
  • Causes. Thyme planted in a pot that is too small, lack of sunlight or competition from other plants for resources or thyme plant that is more than 5 years old.

Thyme plants are relatively compact herbs that prefer to live in soils with low nutrients and little moisture so they do not naturally grow quickly although creeping thyme (Thymus serpyllum) does to grow and spread quickly with full sun.

However, if it is Spring or Summer and your thyme is not growing and looking unhealthy then there is likely a problem with the growing conditions.

Thyme can still grow after 4 years however the growth does naturally slow down and there may be some dieback, with some of the leaves turning brown and drying up which is the natural life span of a thyme plant.

A lack of sunlight can also limit overall growth and the aroma and flavour of the leaves. Nearby plants can also compete for space, light airflow, nutrients and water which can cause the thyme to grow slowly or die.

Pots and containers that are particularly small naturally limit the space for the roots to develop which can cause your thyme to not grow.

How to Revive Thyme Plants that Are Not Growing

  • Plant thyme in a pot or container that is at least 12 inches across to ensure the roots of the plant have enough space to develop so the roots can access the moisture and nutrients it requires.
  • Always locate thyme plants in full sun (at least 6 hours per day) so they can grow and stay healthy.
  • Ensure that thyme plants are planted at least 18 inches apart to ensure there is enough water, soil, sunlight and airflow for each plant. In more humid climates plant thyme around 2-3 feet apart for best results.
  • Thyme plants are not long-lived herbs and the growth can slow after year three and they can die after 4 or 5 years even with good care. Propagate thyme from cuttings in the first and second year for a continuous supply of thyme plants at a low cost.

The smaller the pot or container that you plant your thyme in, the less capacity there is for soil, nutrients and root development. Therefore planting in a larger pot (at least 12 inches across) allows the roots enough space to establish properly which will promote growth.

The larger pots with more soil also insulate the roots from cold and frost so that your thyme plants are more cold-hardy and survive Winter.

Transfer the thyme to a large pot in full sun to encourage growth.

Thyme tends to grow in open areas in its native Mediterranean and it does not tolerate competition from other plants, if your plants are not growing well and are planted less than 1 ft apart or in the same pot then I recommend transplanting the thyme so that they are planted at least 18 inches to 2 feet apart from each other.

With 18 inches of distance, the thyme roots can establish properly and access the moisture, nutrients and sunlight they require. Ensure that the new location is in full sun and the thyme should recover and begin growing again.

The hours of sun per day correlate with the strength of the aroma and flavour of thyme plants with those plants in the full sun having the most pronounced flavour due to the concentration of essential oils.

If your thyme has a life span of 3 or 4 years before it stops growing and begins to die back do not despair as this is fairly typical for this herb even in optimal conditions which is why I always recommend propagating Mediterranean herbs as it is very easy and you can replant your pots and containers for the price of compost, sand and some patience!

Thyme Plant Dying in a Pot or Container

The most common reasons for thyme plants dying in pots are:

  • The pot is too small (not enough nutrients or soil to insulate the roots properly).
  • There are no drainage holes in the base of the pot (or the use of a drip tray).

Ideally, plant thyme in a large pot of at least 12 inches across as a pot this size will not only have plenty of space for the roots to develop but also more soil helps to insulate the roots during Winter.

Smaller pots also heat up quicker in the sun which can dry the soil too quickly even for a plant as drought-resistant as thyme, so transplant your thyme to a bigger pot to help it revive.

If the thyme is showing symptoms of root rot (turning yellow or brown and drooping) despite watering the plant appropriately (water around once per week with a good soak) then ensure the pot has drainage holes in the base and check to see if they are blocked by compacted soil or debris.

Drip trays that catch excess water are also a problem as they can keep the soil damp whereas thyme prefers the soil to become somewhat dry between bouts of watering.

If the soil is damp due to a lack of good drainage then transplant the thyme to a pot with drainage holes in the base and follow the steps above that pertain to treating thyme plants with root rot to try and revive the plant.

Revive Thyme Plants after Winter

Almost all of the varieties of thyme plants that are commonly sold in stores and garden centres are the cold hardy varieties including common thyme (Thymus vulgaris), Lemon Thyme (Thymus citriodorus) and creeping thyme (Thymus serpyllum) and can survive a frost in Winter and grow next year (hardy to USDA zone 5-9).

If you live in a very cold or exposed climate then protect thyme over Winter with perhaps a cloche or bring the pots indoors until the Spring as long as they are placed in a sunny window and watered once every 4 to 6 weeks during winter dormancy.

Thyme tends to be semi-evergreen outside of Mediterranean climates which means it retains some of its leaves over Winter but some may drop off which is normal and the thyme should grow again next year.

If there is any frost damage, snip off the brown foliage during the Spring when the threat of severe frost has passed. If you snip away the frost damage growth during cold weather the new wounds are susceptible to further damage so delay the pruning till there are more mild conditions.

Key Takeaways:

  • The most common reason for thyme plants dying is because of root rot or fungal disease caused by excess moisture around the roots due to overwatering or slow-draining soils.
  • Thyme plants require well-draining soils and only water the plant when the soil has become somewhat dry to avoid the thyme turning yellow or brown because of root rot.
  • If you have used excess fertilizer thyme plants can turn yellow as a sign of stress and the growth can be droop or wilt in appearance. Thyme prefers low to medium fertility soils amended with sand or grit to improve drainage.
  • Thyme plants can begin to die back, dry out and turn brown after 4 or 5 years. Propagating thyme is a good way to keep a consistent supply of the plant at a low cost.
  • Plant thyme in pots that are at least 12 inches across and with drainage holes in the base to avoid damp soil that promotes the conditions for root rot and fungal disease.

Mark Bennett

Mark Bennett is the writer at gardener report. I'm a qualified botanist, landscape gardener and garden center plant troubleshooter! I grow and care for all the plants I write about so I have lots of first hand experience, in troubleshooting problems with plants and providing step by steps tips for recover. I love hearing from you so please leave me a comment and I'll reply!

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