The reason for a dying honeysuckle is usually because the soil is too dry or low in nutrients. Honeysuckle requires consistently moist, nutrient rich soil so if the soil is nutrient poor and too dry the honeysuckle leaves turn yellow and drop off with a dying appearance.
The most common reasons for dying honeysuckle:
- Drought (honeysuckle requires consistently moist soil).
- Low nutrient soil and lack of fertilizer (causes yellow leaves and leaf drop).
- Not enough sunlight (Honeysuckle prefers sun at the vines and shade at the roots).
- Fungal disease (Powdery mildew turns honeysuckle leaves grey with black dots).
Keep reading for what has caused your dying honeysuckle and what you can do to save it…
Honeysuckle Dying from Drought
One of the most common causes of honeysuckle leaves turning yellow and leaf drop is due to drought and dry soil at the roots of your honeysuckle.
Honeysuckles grow naturally in woodlands and in hedgerows in soil that is rich in organic material with a high proportion of decomposed leaves.
Decomposed leaves have an exceptional capacity to hold moisture yet they retain a porous structure that allows excess water to drain away.
This provides the optimal balance of soil moisture for honeysuckles as they require consistently moist soil and suffer if there is a temporary drought.
When honeysuckles are planted in gardens they can suffer from drought despite high rainfall for a few reasons:
- Honeysuckle planted too close to a wall or fence. If the honeysuckle is planted too close to its supporting structure then it can suffer drought as the wall, fence or structure can form a rain shadow and the soil directly near to the wall can remain somewhat dryer then the rest of the garden soil.
- The soil is too sandy/stony and does not retain moisture. Sandy or stony soils are fast draining which is in contrast to the honeysuckles preferred soil type which is moisture retentive, yet well draining in the sense that it allows excess water to drain away from the roots so that the ground does not become boggy which can promote root rot.
- The base of the honeysuckle is in the sun which can dry out the soil. Honeysuckles prefer to have the base of the plant shaded to help keep the roots cool and retain moisture and their vines in the sun which helps to promote flowering.
For more information and best practices for flowering read my article on why your honeysuckle isn’t flowering.
Ideally the honeysuckle should be planted into soil that has been amended with lots of organic matter to retain moisture as this replicates natural conditions in its native woodland habitat and reduces the risk of drought which causes the yellow leaves and leaf drop.
If your honeysuckle is a young plant then it can be lifted out of the ground temporarily whilst you add lots of compost and leaf mould to the planting area to increase resistance to drought.
If the this is nopt possible as your honeyscukle is too mature and established then The best course of action is to…
- Water the honeysuckle regularly in the Spring and Summer. Ideally water the honeysuckle with a generous soak once per week to help mitigate the risk of drought and encourage the roots to establish which further increases drought resistance.
- Add a moisture retaining mulch around the base of the honeysuckle. In the honeysuckles native woodland environment leaf litter acts as a natural mulch and helps to conserve moisture around the roots. Mimic the natural affect of leaf litter by applying a 1 inch layer of mulch around the base of the honeysuckle composed of compost or leaf mould. This should help conserve moisture, improve the soils structure and add nutrients to the soil so that your honeysuckle recovers.
Consistently adding a mulch once or twice per year (ideally in the Spring or Summer) improves the soils capacity for retaining moisture so that the conditions of your garden soil are more favourable for growing honeysuckles.
With consistent watering and the addition of mulch the honeysuckle should recover.
Whilst the yellow leaves may still drop off, the following year the honeysuckle should grow more healthy green leaves and be in better condition to grow and display flowers.
Whilst drought is probably the most common cause of a honeysuckle yellow leaves and leaf drop there are other factors that may cause this such as lack of sun and a deficit of nutrients in the soil…
Lack of Nutrients (Yellow Leaves and Leaf Drop)
Honeysuckles grow to their best when in good soil that is rich in organic matter. If the soil is poor then honeysuckles can die back, not flower as well and the leaves can drop as well as turn yellow.
The soil can be low in nutrients for a few reasons:
- If the honeysuckle has been in the same place for soil for a long time without any additional nutrients from fertilizer or mulch then the roots can exhaust the soil of nutrients.
- Honeysuckles that are planted close to a wall have a limited area for their roots to grow and access nutrients (because of the foundations of the wall) compared to honeysuckle growing on a trellis or fence.
- Honeysuckles are woodland plants so the leaf litter acts like a mulch every year adding nutrients to the soil so it stays healthy. If you do not apply any mulch to your honeysuckle then it can exhaust the nutrients of the soil which can cause it to die back.
- Occasionally I see honeysuckles planted in pots and containers. Pots and containers have a less capacity for soil and therefore less capacity for nutrients and moisture which can cause yellow leaves and the honeysuckle to have a dying appearance.
The key to reviving honeysuckles that are suffering because of a nutrient deficit in the soil is to:
- Mimic the affect of woodland leaf litter by adding mulch around the base of your honeysuckle every year to add nutrients and conserve moisture, creating more favourable conditions for your honeysuckle.
- Apply a balanced fertilizer to the soil in the Spring for additional nutrients.
Apply a 1 inch layer of compost or leaf mould around the base of your honeysuckle in the Spring and perhaps again in the Summer.
This should mitigate risk of drought and improve the soils nutrient profile so that your honeysuckle has all the resources to thrive and display flowers.
Consistent mulch application can improve nutrient poor soils so that they emulate the soil of the honeysuckles natural environment.
Additional fertilizer can be improve the appearance of your honeysuckle and is important to help revive the plant.
Always use a balanced fertilizer rather then a nitrogen based fertilizer.
I personally recommend a product such as miracle-gro granulated fertilizer as it is easy to apply with the correct balance of nutrients at the right concentration.
This product also ensures that the nutrients are are released slowly which reduces the risk of problems associated with too much fertilizer (which can prevent honeysuckle form flowering).
Not Enough Sunlight
Honeysuckles thrive when the roots are in the shade and the vines are in the sun. Whilst full sun is not necessary, partial sun or significant dappled light is required to promote flowering.
Honeysuckle uses its climbing vines to find sun so that it has the energy to flower.
Full shade is not only detrimental to flowering but also can cause leaf drop and a yellowing of the leaves.
If the leaf drop and yellowing of leaves is localised to perhaps the lower half of the honeysuckle and the rest of the plant looks in good health then this may be because the upper half has climbed so it is in direct sun.
The honeysuckle often only invests in the growth of leaves that are in a position of sun which causes the plant to drop leaves lower down the plant.
If vines of the honeysuckle are healthy and in the sun yet the lower half is dropping leaves then there is not immediate concern for the rest of the honeysuckle and it is unlikely that the plant is dying.
If necessary you can plant a shrub that prefers shade (hydrangea or rhododendron) in front of the honeysuckles lower half so you can’t see the sparse growth or you can be assured that the honeysuckle is likely in good health and the vines that are in the sun should flower.
In areas of full shade you can either cut back the canopy of any overhanging branches for more light or transplant the honeysuckle to a sunnier location as they often do not live long or flower well in full shade.
Honeysuckle with Fungal Disease
If your honeysuckle has a grey/white mould on the leaves often with black dots and potentially the leaves are dropping, then your honeysuckle has a fungal disease called powdery mildew.
Honeysuckle is unfortunately susceptible to powdery mildew however it does not necessarily mean your honeysuckle is dying and with the right care, the honeysuckle can be revived. However recovery depends on how early you catch the infection.
The risk factors for honeysuckle with powdery mildew are:
- Regular drought stress. If the honeysuckle frequently experiences drought or dry soil because of weather, sandy soil profile, lack of mulch or regular watering then it less resistant to infection.
- Too much fertilizer. Too much nitrogen in the soil because of frequent application of fertilizer or high concentration of fertilizer (or run off from lawn feed) can increase foliage growth that is more susceptible to powdery mildew. Always use a balanced fertilizer with equal parts Nitrogen, Phosphorous and Potassium (NPK) rather then a nitrogen based fertilizer.
- Not enough sun. A lack of sun is not usually the main cause of powdery mildew infection susceptibility but nonetheless a contributing factor. Most honeysuckles require some sun on the vines to flower and stay healthy.
- Higher levels of humidity. Avoid watering overhead and water at the base of the honeysuckle and prevent a humid micro climate by trimming back surrounding vegetation and cut back any unproductive wood on the honeysuckle to improve airflow.
- Nutrient poor soil. If the soil is sandy or there has not been any applications of mulch or fertilizer then the honeysuckle is more vulnerable to powdery mildew.
To treat powdery mildew the most important step is to:
- Cut back any infected foliage back with a sterile pair of pruners
- Use a cloth soaked in disinfectant to wipe the blades between each cut to prevent transferring the fungal spores to otherwise healthy growth on the honeysuckle.
- Collect up any infected leaves and burn them or discard them in a bin to kill the fungus and prevent it spreading.
- Use a treatment of neem oil (available from garden centers and online). Neem oil is a non toxic fungicide and safe for organic gardening. Generally it only takes a few spray applications to the leaves to treat the powdery mildew but always follow the manufactures instructions.
With good care, regular watering and treatment honeysuckle can make a full recovery from powdery mildew.
Applying a balanced fertilizer can help in recovery as powdery mildew can stress the honeysuckle and reduce nutrient availability.
- Dying honeysuckle is usually because of drought or a lack of soil nutrients. Drought and nutrient deficient soil cause the honeysuckle’s leaves to turn yellow and drop off and the vines to die back.
- Lack of sunlight can also cause yellowing of leaves and leaf drop on the vines. Honeysuckle prefers the roots in the shade and the vines in the sun for flowering.
- Honeysuckle with grey or white leaves with black spots has powdery mildew. Honeysuckles can revive from powdery mildew with consistent watering, added mulch and the use of fertilizer. Cut back any affected foliage and spray the plant with neem oil and the honeysuckle should come back the following year.
- Honeysuckle is a woodland plant that requires soil composed of organic matter such as leaf litter for moisture and nutrients. Replicate their natural conditions by mulching around the base of the honeysuckle with leaf mould or compost.