I enjoy the beautiful purple flowers that I get growing lavender. But sometimes it can be a problem finding some of the plants turning grey.

Your lavender is turning grey because it may have been infected by fungal diseases such as Botrytis blight. It may also turn grey due to frost damage, overwatering, lack of pruning, lack of nutrients, or a small growing space.

I’ve written all the details below that will help you figure out the problem with your lavender plant and the steps you can take to solve it.

Fungal Diseases

Fungal diseases are a fairly common reason why lavender plants start to turn grey. Often, the Botrytis fungus will be responsible. You should be able to spot the damage occurring at the base of the plant. 

There are a few reasons why your lavender plant might have developed a fungal infection. For example, you might have used soil that is slow to drain.

It’s also possible that you might have planted the lavender too close to other plants. This reduces airflow. Sometimes, there won’t be a drainage hole in the base of the pot. All of these mistakes will cause the soil to become too damp. In wet conditions, it will be easier for fungus to take hold. 

If you think that fungal disease could be responsible for the lavender turning grey, you need to take prompt action. This will stop it from spreading throughout the garden and infecting other plants. First, you’ll need to remove the lavender plant from the soil or take it out of the pot.

Then, trim away any gray stems. Between each snip, you should dip the shears in alcohol. This will kill the fungus, so you don’t accidentally spread it to uninfected parts of the plant. If you want to go the extra mile, you can burn the affected leaves. 

Next, you’ll need to treat the soil. If you had it in a pot, you’ll need to throw out the potting mix. Rinse the pot. If it was in the ground, try to remove as much of the old soil as possible.

Spread a fungal mix throughout the soil. This will kill any trace of the infection. Finally, it will be safe to replant the lavender. Though it might take a few weeks, the lavender will often make a full recovery from a fungal infection.

Frost Damage

Low temperatures can be quite damaging to the lavender plant. In this case, the grey areas will be caused by the cold killing off the new growth.

Sometimes this will be happening because you choose the wrong variety of lavender. It won’t be able to cope with the cold winter temperatures. If you live in a colder climate, it might be best to choose the English Lavender variety

After the winter, the grey leaves can seem grim. But there is still hope. Often, if you prune away the grey sections, you can encourage new growth. If you do this, it will develop a thicker stem. This will make it easier for it to cope with future winters. 

You should also make sure that you’re prepared for the upcoming winters. There are a few simple tips you can use to do this. First, you’ll want to water the plant more often. But avoid overwatering, you don’t want to give it a fungus.

If it’s in a pot, you can move it to a spot that’s out of the wind and doesn’t get any snow. If you want to go the extra mile, you can knit the lavender a cover. Though a breathable mesh, available at most hardware stores, is just as good.

Overwatering or Underwatering

Damp soils have the potential to create a fungal infection. This, in turn, can cause the plant to develop grey patches around the base. Because of this, overwatering can pose a real risk to your lavender.

Sometimes, you might have the opposite problem. You might not be getting enough water to the lavender. When this happens, it won’t be able to form deep enough roots. This can be the reason why the branches are drooping. 

The key to preventing both of these issues is knowing the right amount of water to give your lavender. When you first get the lavender, you’ll need to water it once or twice a week. This will give it some time to establish strong roots.

Once it starts to mature, it will only need to be watered once every two to three weeks. Once buds start to form, you’ll need to switch back to water them once every one to two weeks until the harvest.

Lack of Growing Space

Sometimes, the lavender plants will be spaced too closely together. This reduces airflow around the base and increases the chance of a fungus developing. Cramped spacing can also make it harder to establish a strong root system. 

When positioning the lavender, you should try to give them a spot that has full sunlight. You should also try to put them around two to three feet apart.

At the start, this can appear like a large gap. But, as the plants grow, they will take up more space. If you follow this, you can form a lavender hedge. This garden feature will look, and smell, great.

Lack of Pruning

Like all plants, it’s important to make sure that your lavender is pruned properly. This will help it maintain strong growth. It’s also your chance to remove any dead flowers. If you don’t prune it, it might start to turn grey.

If you ignore this and don’t take action, it can develop a wooden base. Over time, the base might start to split apart, which will significantly shorten the life of the plant.

There are a few tips that you can use when pruning your lavender. Often, you’ll need to prune twice a year. Once, before the winter and again as the temperatures start to climb again. The way that you’ll need to prune them will depend on how old the plant is. 

When you have a young plant, you’ll want to prune away most of the growth after the first year. As they start to mature, you can trim more aggressively. Make sure that there is plenty of space between the branches.

This provides lots of airflow, reducing the chances that they will develop fungal disease. If you have older lavender, a heavier prune will wake them up from a dormant state. 

With these guidelines in mind, there are a few steps to the pruning process. First, you’ll want to sharpen your blade. This will give you a clean cut. It also reduces the amount of effort you need to expend to cut through the branches.

You’ll need to get rid of any deadheads and damaged sections of the plant. If the branch is grey, get rid of it. Then, you can work on shaping it. Try to form a gumdrop shape. Not only is this pleasant, but it also provides the right amount of airflow. It should look symmetrical all the way around.

Lack of Nutrients

Like humans, plants need food to grow. Without the right food, it will start to starve and die. This could be the reason why your lavender is starting to turn grey. 

This is one of the easiest problems to solve. First, you’ll need to determine what kind of soil you have. This will tell you what type of fertilizer you will need to use. Lavender will prefer acidic soil. If the soil test shows that the ground is alkaline, you’ll need to add some lime. This will help you raise the pH levels.

If it’s already acidic, you won’t need to do too much. If you want to make the blooms more colorful, you can add some potassium to the soil. Avoid high nitrogen or heavy manure mixes. This will cause the lavender to become sappy. 

As long as you do this, the lavender will grow strongly. You’ll only need to apply fertilizer twice a year. It’s best to do this during the spring and fall. If you are growing them in a pot, the same fertilization routine applies. 

Often, the conditions you are growing the lavender in are more important than the type of fertilizer you are using. You’ll need to make sure that they are getting six to seven hours of sun per day. As we mentioned, you’ll need to make sure that the soil is draining properly.