For a gardener, there are few things more dismaying than looking out onto your “kingdom” and noticing some plants are looking, well… Less than happy.
Lavender is known as a hardy, drought-tolerant, and low-maintenance plant. But there are still conditions that may cause your lavender plant to decline – such as overwatering, underwatering, fungal diseases, and even heat stress!
If your lavender looks less than lush, it’s time to get your hands dirty and investigate. With some skill and luck, you’ll find the cause and revive your dying plant.
Signs of Dying Lavender | Overwatering | Underwatering | Soil Problems | Low Sunlight | Fungal Disease | Pests | Fertiliser | Heat Stress | Transplant Shock | Dying Potted Lavender | Reviving Dying Lavender
Is My Lavender Dead or Dormant?
First thing you need to check – is your lavender plant dead or just dormant?
If your fragrant flowers have faded and your plant seems to have stopped growing, don’t think the worst just yet! Lavender, like many plants, goes dormant during colder months.
These hardy plants are “resting” since there’s generally less sunlight, so they don’t put energy into new growth – meaning no green stems or leaves.
However, if you notice things like brittle, dried-out stems or soft, wilted leaves… Well, it may be time to grow new lavender.
It’s important to remember that lavender isn’t a forever plant, and even with regular care (like pruning), it’ll become ragged and woody after several years.
While you have these beautiful plants, though, make sure you care for them properly (or tag in some gardening professionals to help).
Signs of Dying Lavender Plants
When growing lavender, it’s good to know the signs of a healthy plant – and a dying one.
The earlier you catch a problem, the more likely you are to save it!
Some signs of a dying lavender plant include:
- Drooping or soft stems
- Lack of flowers or dying flowers
- Yellow, grey, and/or wilting leaves
- Brittle, dried-out stems and branches
- Yellowing or rot around the plant base
- Dark (brown or black) and mushy roots
A dead lavender plant looks completely brown, with no green growth anywhere, and dried-out or rotted roots.
Reasons for a Lavender Plant Dying
When planting lavender, the last thing you want is to kill off that beautiful growth. But if you’ve seen the warning signs, you need to identify the cause quickly – that’ll help you save your lavender!
One important factor is choosing the right type of lavender to grow! Hybrid plants like Lavandin, for example, are more heat tolerant than the “delicate” French lavender.
If you grow lavender that isn’t suited to your environment or climate, its chances of thriving are slimmer.
Overwatering
Like other plants, lavender does not like wet feet! Lavender plants are prone to root rot, so it’s essential you don’t leave them in soggy soil.
Soft or mushy stems, yellowing leaves, and drooping foliage are key signs of overwatering. If you can check in the soil, look for dark, mushy roots and a funky smell.
Crown rot (from Phytophthora) is also a sign of overwatering – rot or foliage death around the sides and base of a lavender plant.
If you companion plant lavender, make sure you grow plants that have compatible water requirements. Otherwise, it’s better to grow lavender in pots to maintain their ideal growing conditions.
SOLUTION: Stop watering and let the soil dry out completely. Then wait a bit longer before you water again. For plants with signs of root rot, you will have to repot them or change the soil and cut off any affected roots.
When watering lavender, less is best. It’s a hardy plant and can tolerate drought. Young plants will need a bit more watering, but mature plants can dry out between watering – especially in cooler months.
Underwatering
These may be drought-resistant plants, but lavender still needs water to grow!
Underwatering is tricky to diagnose, since the symptoms can look like overwatering: droopy foliage and yellow leaves. However, underwatered lavender will start showing dry leaves with brittle, brown tips.
The soil will also feel almost brittle as it’s too dry. Some parts of the plant may have dried out as well.
SOLUTION: Avoid the temptation to completely drench the soil! The roots may not be able to take up water properly, and could eventually rot in the wet soil.
Instead, water enough that the soil is moist all the way through, and monitor closely. Water again when the soil is halfway to most of the way dry.
If the soil has turned hydrophobic (meaning it no longer absorbs/holds moisture), then you’ll either have to do a long bottom water or replace the soil entirely.
Soil problems
Lavender has adapted to grow in “poor soil” – meaning soil that has low nutrients, slightly high pH, and plenty of sand or gravel.
When grown at home, lavender plants need well-draining soil that’s alkaline (up to about 7.5 soil pH). Compacted, acidic, or heavy soils can suffocate the roots or hinder growth.
SOLUTION: You’ll need to amend the soil as necessary. For example, for acidic soils, you can raise the soil pH by adding agricultural lime or finely ground eggshells.
Compact or heavy soils can be amended with sand, perlite, pumice, and gravel.
Not enough sunlight
Lavender grows best in full sun – six hours a day, at least! It can tolerate partial shade, but lack of sunlight can severely stunt its growth.
Consistently not getting enough light will result in leggy, spindly growth as the plant tries to search for the sun. Keep it in these conditions for too long and the plant will begin dying.
(Conversely, too much direct sun could crisp and burn your foliage – be mindful of that, too.)
SOLUTION: Grow lavender somewhere sunny, and make sure it’s not too crowded! Move potted plants near a window or out to a patio.
For outdoor lavender, try not to grow it in a shady area – although make sure it’s sheltered from any strong winds.
Fungal disease
Root rot is partially caused by fungi in soil, but it’s more directly tied to overwatering or soggy soil.
There are other fungal diseases that can affect lavender plants, usually caused by too much humidity, pest infestations, or infection spread from other plants.
Alfalfa mosaic virus comes from improperly sanitised tools or an aphid infestation. It looks like a yellowish mosaic pattern on foliage and twisted leaves.
Shab (Phoma Lavandulae) attacks lavender plants in particular, particularly the stems. Black spots are a key sign of shab, which can be airborne.
If your lavender plant is turning grey and dying, that could be Botrytis or Septoria lavandulae. Both are caused by high humidity and poor air circulation, but Septoria only targets lavender.
Botrytis starts out grey then turns white and fuzzy, while Septoria has grey-and-brown spots that slowly spread over the foliage.
SOLUTION: For mosaic virus and lavender shab, there are no cures. You’ll need to uproot and remove the plants immediately to keep the disease from spreading. Do not compost infected plants.
However, Botrytis and Septoria can be treated with an appropriate fungicide and a reduced watering schedule (to lessen dampness and humidity).
Pests
Lavender plants typically don’t attract pests – and in fact, are often used as companion plants to repel other pests or attract beneficial insects. However, there are still some to look out for!
In Australia, common lavender pests include whiteflies, aphids, and scale. Mealybugs can also get your lavender, especially the English variety.
SOLUTION: Treat your plants with the appropriate form of pest control. Some “natural” solutions include insecticidal soap (made from Castile soap) and neem oil.
Prune the plant to improve airflow and light, which can reduce pest populations.
Fertiliser
Lavender typically doesn’t need fertilising, especially English lavender! They’re endemic to areas with poor soil conditions and nutrition.
As flowering plants, lavenders are prized for their blooms. Too much nitrogen from fertiliser is detrimental to flowers, as the plant will instead grow lots of branches and leaves.
Excess nitrogen leads to drooping stems, leggy growth, and stunted plants. The foliage will also turn yellowish, starting from the base.
SOLUTION: You can try to flush the area with a deep soak of water (ideally right when your plant needs watering). Prune off excess growth to redirect the energy to the roots.
If all else fails, dig out and change the soil around your lavender plants, or move them to an unfertilised medium.
Heat stress
Lavender is very drought-tolerant, but even these hardy plants can’t tolerate everything! Between 40º-45ºC (104º-113ºF) is the danger zone, and anything above 45ºC will stress the plants.
English and French lavender are particularly prone to heat stress at high temperatures.
This is especially true for outdoor plants, since you’re less able to control or fix their growing conditions.
SOLUTION: You can water a little more often, keeping the soil moist but not waterlogged. A less risky solution would be to layer organic mulch or rocks around the base to retain moisture and cool down the soil.
For outdoor potted lavender, move them into shadier spots (or even indoors if possible). Keep them out of direct sunlight in the afternoon.
Transplant shock
This primarily happens if you propagate your lavender in water instead of directly in soil.
Lavender cuttings that have rooted in water have a harder time adapting to a drier medium, like potting mix. They may suffer transplant shock, causing the stems and leaves to wilt.
It can also happen if you’re repotting your lavender, or moving it from a pot to outdoors. Things like aggressive handling, accidental root damage, and drastic changes in temperature/humidity can also cause transplant shock.
SOLUTION: There’s nothing else to do except carefully manage the plant in its new environment.
Pay special attention to watering – don’t let the potting medium get waterlogged, and allow the plants to adapt to their new home.
Sometimes, though, new plants simply will not take and will die off in the pot or ground.
Why is My Potted Lavender Dying?
For lavender grown in pots, the most common reasons for dying plants are overwatering and lack of sunlight.
Anyone who keeps indoor plants knows how easy it is to accidentally overwater a plant! Lavender in particular likes to dry out in between watering, and it’s better to underwater than overwater.
For lavender in pots, it’s essential to have both well-draining soil and a pot with drainage holes. Otherwise, the potting mix won’t dry out properly, leaving your plant with wet feet.
Where you put the potted plant also matters. Lavender likes plenty of sunlight, so place it by a window that gets full sun in the mornings.
Adequate sunlight also helps the potting mix dry out.
However, if you keep a good watering schedule and you feel your lavender drying out quickly, that might be a sign that it’s rootbound! There are more roots than soil, so the plant absorbs the water faster than normal.
That’s an easy fix – simply transfer your lavender to a larger pot. Water before transplanting (at least 1-2 days before) to minimise the risk of transplant shock.
Will Dead Lavender Grow Back?
Completely dead lavender will not grow back, no matter what you try.
But if there’s any remaining healthy growth – especially roots – then you have a chance!
Signs you can still revive your lavender plant
If there’s any green left on your once-healthy plant, your lavender can still be saved.
Check the plant’s roots as well – any firm, white roots mean the plant can be repotted or transplanted and nurtured back to full health.
How to revive a dying lavender plant
This will depend on the reason for lavender plants dying. For overwatered plants, cut off dying roots and let the soil dry out before watering again.
For underwatered or overheated plants, carefully introduce more water and prune off any dried-out foliage.
Soil issues such as compaction, excess nitrogen, and acidity can be fixed by amending the soil with the appropriate material.
Find the correct treatment for pests and fungi – although, for mosaic disease or lavender shab, it’s best to dispose of the affected plants immediately. Do not put them in compost, as the disease could spread around your garden.
If all else fails, uproot the plant and cut off any unhealthy parts (down to the roots!). Then place it in new soil and treat it like a cutting as you nurture it back to new growth.
FAQs About Lavender Plant Care
Let’s top things off with some answers to common questions about a lavender plant dying.
Why is my lavender turning yellow?
Yellow leaves on lavender are a sign of either underwatering or overwatering.
Squishy stems or roots signal overwatering and root rot, while brittle growth signals too little water.
What does overwatered lavender look like?
Signs of overwatered lavender include yellowing and limp leaves, drooping stems, and stunted growth.
When checked, the roots will look dark (brown or black) and feel mushy.
Will my lavender die if I don’t prune it?
If you don’t regularly prune your lavender, it can lead to spindly, woody, and otherwise unruly growth. Your plant’s branches may become congested, leading to a scraggly appearance and a lack of airflow.
Eventually, the lack of circulation could lead to disease or poor growth – that yes, could be the death of your plants.
