What is Wrong With My Bay Tree
Broadly speaking, bay laurel (Laurus nobilis) is an easygoing evergreen tree that should give many years of pleasure in your garden. No tree or plant is ever entirely maintenance-free, however, and it’s worth knowing about the handful or so of common problems that can affect bay trees so you can deal with them effectively as they arise. As with so much in gardening (and life in general!), spotting and heading off issues before they escalate is half the battle. Our guide to troubleshooting the six most frequently encountered issues gives all the information you need to ensure that your bay tree lives long and prospers.
Bay Tree Leaves Turning Yellow
There are usually two possible causes of yellow leaves on bay trees. Yellow leaves can be a sign of excess water, a common problem if you grow your bay in a pot and are overwatering it. If this is the case, ease back on your watering regime and perhaps consider changing the growing medium to a more free-draining John Innes based compost or a specialist compost for containers.
The other cause of yellowing leaves is nutrient deficiency. This is generally more of a concern with pot-grown trees, which cannot access nutrients in the same way as plants growing in the ground. Regular applications of general purpose fertiliser during spring and summer are an easy and straightforward solution to this common bay tree problem. Pick off affected leaves and dispose of them by burning or composting.
Bay Tree Leaves Turning Brown
Brown leaves can be alarming to see on any plant, but especially on a bay tree whose chief glory is its aromatic dark green leaves. In many cases, the problem is a simple lack of water. Whether grown in the ground or in a container, bay trees will become stressed and develop brown leaves if they can’t access enough water to thrive. If the soil is dry when you dig a small hole near the tree’s roots, solve the problem by making sure your bay tree has sufficient water (but not too much – you don’t want it to suffer from yellow leaves, as above!).
Peeling or cracked bark can be another sign of stress in bay trees, with fluctuating moisture levels or extreme winter cold being the most likely culprits. Although bay trees are hardy down to at least -5℃, if the temperature drops below this for extended periods, peeling bark can be the result. Luckily, no intervention is usually required, and the tree will revive when the weather warms up. If you are growing a bay tree in a container, you can protect it from extreme cold by using a horticultural fleece, or by moving it into a sheltered frost-free greenhouse or porch.
Bay trees prefer free-draining soil, and if their roots become waterlogged, leaf spotting can occur. Avoid this problem by adding extra drainage to the soil, and if growing in a container, don’t overwater, and when watering, allow the excess water to drain away. Leaf spots can also be a sign that container-grown bay trees need to be repotted. If possible, remove from the container and fresh the compost completely in spring, making sure the pot has sufficient drainage.
These sap-sucking bugs are a common pest on bay trees. Resembling a flat waxy disc, these inconspicuous insects are found on the underside of leaves and stems. In themselves, they cause little damage to the tree, but they do excrete a copious sticky residue on the leaf surface, which in turn is colonised by black sooty moulds.
Not only are these unattractive, but they can inhibit photosynthesis (the process by which plants convert light into energy through their leaves). You can control small infestations of scale insects by picking them off by hand or by using a suitable organic pest control spray. Alternatively, encourage natural predators such as ladybirds into your garden or use a biological control such as the nematode Steinernema feltiae.
Bay sucker (Lauritrioza alacris) is a sap-sucking bug that feeds on bay leaves, causing them to become discoloured and distorted at the shoot tips. Affected leaves ultimately turn brown – not a good look on a bay tree. If you suspect an infestation, check the undersides of the leaves – the presence of small greyish-white insects will confirm that the problem is bay sucker.
Fortunately, bay suckers rarely cause any lasting damage to the tree. They can be controlled by encouraging natural predators such as ladybirds, birds and ground beetles into the garden or by carefully applying appropriate organic pest control.
As we have shown, bay tree leaves turning yellow and brown are the most common sign that your bay tree has a problem. Simply ensuring that your bay tree is fed and watered correctly is often the only step you’ll need to take to rectify the issue. Regularly checking the leaves for pests is another straightforward precaution that will enable you to take timely remedial action. When planting a new bay tree, ensure that the soil has adequate drainage and use mycorrhizal fungi to help it establish quickly and strongly in optimal growing conditions. Further down the line, an application of mycorrhizal fungi-enriched top dressing will benefit established plants by promoting strong growth and helping them shrug off problems more easily. Browse our bay tree sizes to find the bay laurel tree that’s right for your garden.