Last Updated on November 1, 2022 by Stephanie
The color of lavender can change because due to frost injury or because of a fungal infection due to over-watering and slow drainage of soils. The fungus botrytis spp is the cause of lavender leaves turning gray, however there are some pathogens that can cause lavenders to change color.
Luckily, the treatment options and best practices to prevent the different fungal illnesses that can cause the lavender to go gray is the exact same.
It is important to note that there are a variety of lavender varietiesand the leaves can range from dark green to an almost gray, silvery color So your lavender could be fine.
Continue reading to discover whether its damage from frost that is causing the lavenders leaves to turn gray or fungal diseases and the best way to keep the laurel…
Table of Contents
Fungal Disease Causing Lavender to Turn Gray
Fungal diseases like botrytis species is the main reason for lavender leaves turning gray , and it usually happens to the leaves near the plants base.
All varieties of lavenders originate in the breezy and dry coastal climate in the Mediterranean in Europe which is where they have adapted to well-drained, sandy soils that have moderate to low soil nutrients.
In those conditions where lavender is at its peak and is disease-free. To ensure that lavender grows successfully gardeners must recreate the soil conditions that keep away fungal diseases which turn the lavender color.
Frost Damage Causing Gray Foliage
Its possible that the lavender foliage appears brown or gray due to damage from frost or it may be the result of last years growth that requires pruning. English Lavenders can be cold-hardy and can withstand frigid winters with frost, snow freezing temperatures, ice and snow.
Beware of Spanish, French and Portuguese lavenders since they arent cold-hardy and are often afflicted in cold winter climates.
Cut lavenders back in the spring to encourage the growth of new plants (which encourages flowering) and improves the lavenders durability.
Heres a helpful YouTube video that shows you the grey foliage of last years garden appears like in the spring and how to trim it back efficiently:
(For all the most effective ways to care for your plants, check out my article on on how you can plant lavender inside pots).
How to treat Lavender by Gray Foliage
The treatment for lavender that is associated with fungal infection is usually similar. When you take care to treat it within a certain the right time, there is a high chance it will be able to be able to recover from the fungal infection which caused the gray foliage. The lavender will grow normally the following year.
- First, take your lavender plant from its pot or ground and examine the roots for any signs of fungal disease. If the roots appear to be rotten cut off the affected roots using the help of a sterilized pair of pruners. Clean the pruners with alcohol-based disinfectants following each cut to stop the fungal infection from spreading.
- Cut off any lavender leaves that are gray or stems with care and then dispose of them and burn them in order to stop this fungus spreading throughout the garden.
- Remove the potting soil because it contains bacteria that can infect other plants. Apply an organic fungicide that kills any fungus that is present in the soil in which your plant your lavender. Do not plant any additional plants within the same area for a period of time.
- Replant the lavender in fresh dirt in pots, so that you are able to control the soils characteristics and prevent any infections that could be a possibility.
- Add approximately 1/3 horticultural sand , or grit, and 2/3 compost or potting soil. (Read this article and find out how to make the ideal soil mix for the lavenders). This will recreate the lavenders prefers sandy soils in its natural habitat and improve drainage, while also providing the proper balance of nutrients for lavenders since lavenders like low to medium nutrient soils.
- After the lavender has been planted in the new pot, protect it from rain and dont give it water for two weeks if the roots show indications of decay.
- The lavender should be placed in the full sunlight and water it every two weeks up to the end of fall.
Lavender is often cured of botrytis spp, among other illnesses which cause it to change gray, so dont worry about it.
It is important to note that fungicides are effective to kill fungi in the soil, but when the lavender is already affected by the fungus the fungicide wont help to treat the lavender.
It is necessary to cut off any affected parts of the plant in order to ensure that the lavender has the best chance of recovering.
Make sure that lavenders are planted at least at least a couple of feet from one another to permit airflow. More humid, or quiet the weather the more important that you plant lavenders at a at least a good distance from each the other in order to avoid fungal diseases.
Dont use any mulch that retains moisture (such like leaf mold) in the vicinity of lavender plant and remove decaying leaves, or other organic material from around the plant to ensure that the soil is able to dry and the roots remain healthy.
Avoid excessively rich in nutrients soils and amendments to soil such as manure, or the use of fertilizers. The lavender prefers soils with low to moderate nutrient levels. When theres too high levels of nitrogen in the soil, the lavender can grow leggy with lots of leaves that is more prone to fungal diseases.
Make sure to amend the soil with sand or grit prior to planting lavender in order to ensure adequate drainage and to establish the conditions for lavenders to like. The lavenders thrive in poor care and are their most healthy scent, most fragrant and show the most flowers in dry, harsh conditions.
The water lavenders are located at the base of the plant instead of over the top to limit the time that the foliage remains damp, which could increase the chances of fungal diseases.
(For more details, please read my article on what is the best time should you water your the lavender).
Make sure to plant your lavender under full sunlight to ensure a healthy, disease-resistant plant that has an intense scent and a beautiful arrangement of flowers.