Bay Care Guide - Caring for Laurus nobilis Topiary

How to Care for Bay Trees

We would like your bay tree (Laurus nobilis) to be happy and healthy and last for years to come.

On this page you will find our care advice specifically for bay trees that will let you know what your plant needs.

We have also included our recommended products, products that we use ourselves, that will help you keep your plant looking at its very best.

 

 

Bay Tree Care Instructions

Common name	Bay Tree
Latin name	Laurus Nobilis (aka Lauris Nobilis)
Description	Bay trees are sometimes known as sweet bay and are valued for their evergreen aromatic leaves which can be used for culinary purposes. They make handsome container plants and are easily clipped to shape. Originally from woodland areas of the Mediterranean these plants are frost hardy down to minus 5 degrees centigrade. It is therefore beneficial to move container plants to a cool greenhouse, conservatory or porch for the winter and early spring in cold areas. In milder areas of the country these plants can be successfully grown outside, good drainage and careful positioning in a sheltered area and  protection from cold and strong winds are necessary.
Height / Spread	Ultimate height: 12m Ultimate spread: 12m Time to ultimate height: 20-50 years
Pruning	Bay trees respond well to pruning, pruning should be carried out with secateurs if you require a neat finish. Shears damage the large leaves and the result is unsightly. Prune bush bay trees in spring or early summer, pruning back to an outward facing shoot. The purpose of this pruning is to produce a bushy plant of the size required. Bay trees take a long time to respond to hard pruning so it is best to do the job on a regular basis, with the end result in mind. Pruning of topiary specimens is best carried out in the summer removing any vigorous growth and keeping the shape of the head neat and bushy. When removing leaves for culinary purposes, consider any leaves that are out of place on the head first. Remove any growth from the stem and suckers from the base as they appear. Female plants will bear black fruits which can be removed if desired.
Watering	Bay trees in the open ground should not need watering once established. In containers watering is very important but should not be over applied. Moderate and regular watering is ideal. Overwatering can cause root damage. Placing containers so they are slightly off the ground will help to keep the roots healthy. Some problems such as, leaf spots and yellowing of the leaves can be caused by overwatering.
Feeding	During the growing season use either a slow-release balanced fertilizer that will cover the whole period or apply a balanced fertilizer every two weeks. Yellowing leaves can be a sign of nutrient deficiency.
Potting On	Bay trees can remain in containers for many years. When re potting it is important to use a loam-based compost such as John Innes No 2 and only increase the pot by one size adding horticultural grit to the mixture to aid drainage. Even if you do not want to put the plant in a larger container it is beneficial to remove the plant from the container every 2-3 years and carefully scrape off some of the compost from the roots and replace it with new. All re potting is best done at the beginning of the growing season so the plant can benefit from the new nutrients.
Pests	Bay trees can get bay sucker, horse chestnut scale, soft scale and tortrix moth
Diseases	Powdery mildews and a leaf spot may be a problem with bay trees
Soil	Acid, alkaline or neutral. Well-drained. Chalk, clay, loam or sand
Aspect	All aspects. Sun or partial shade. Well drained soil. Exposed or sheltered site
Hardy	Frost hardy down to -5C. Protect from extreme cold levels.
Winter Care	You should treat your bay tree according to your local weather conditions. Bay trees are frost hardy but extreme cold and or wind can damage leaves. Move your plant to a sheltered area for the winter. If the weather turns colder then you can protect the foliage with horticultural fleece for the duration of the cold. You can also wrap the container with bubble wrap as this will keep the roots protected. Placing your container on small bricks or similar ensures the plant has good drainage and helps prevent damage to the roots. If your plant is to be grown in the open ground ensure a sheltered site for the best results. Any damaged leaves caused by the winter cold can be removed with secateurs in the spring.
Evergreen / Deciduous	Evergreen.
Fragrance	Foliage
Suggested uses	Coastal, hedging / screens or low maintenance

Bay Tree Problems

Yellow or Brown Leaves

Causes

Bay trees will naturally shed older leaves in small numbers turning yellow before falling off. When grown in containers however, this could be caused by a nutrient deficiency, waterlogged compost or cold weather damage. If caused by a nutrient deficiency it is likely to be nitrogen deficient. Nitrogen promotes green, leafy growth but is soluble and is easily washed out of the soil during winter rains, leaving the soil deficient in spring.

Control & Prevention

Apply a high nitrogen fertiliser such as sulphate of ammonia or chicken manure pellets as a short term solution. In the long term however, your bay will benefit from an organic mulch such as well rotted garden compost or manure to provide a steady feed of nitrogen.

If yellow leaves of plants in containers are caused by waterlogged compost you must ensure the container is never standing in water, raise with bricks or pot stands so excess water can drain away. Only water again when the top part of the soil to a depth of 3cm/1 inch feels dry.

If bad weather has caused damage by either the cold or wind then you will need to protect your bay tree. They are susceptible to damage when the temperature drops below -5°C (32°F) so best positioned in a corner preferably with one side facing the wall of a heated house and out of strong winds.

In general, dead leaves, compacted soil and underfeeding all contribute to the general health of your bay tree. The removal of dead leaves and the replacement of the top 3cm of soil with fresh new compost will improve the overall health of your tree.

Peeling Bark

Causes

The peeling or cracking of bark is an environmental problem rather than a pest or disease and while the cause is uncertain it is usually the cold or fluctuating soil moisture levels. If containerised it is likely to be caused by overwatering or allowing the soil to dry out followed by overwatering, this causes the trunk to swell, splitting the bark.

Control & Prevention

Restrict and maintain a constant level of water. Bay trees can tolerate a lack of water for around one month, if this is the case, don't over soak but gradually water back to a moist condition over the course of 3-4 weeks.

Bad drainage can cause an accumulation of water in containers. Raising these off the ground with brick or pot legs allowing excess water to drain away can improve conditions.

Prolonged periods of cold weather can cause splitting and cracking. Frosts get into small cracks opening them up further. Split bark cannot be remedied however, if the upper part of the tree is in good shape with healthy leaves it should be fine providing drainage is good. Moving containerised plants to more sheltered positions can also improve the health of bay trees.

Bay Tree Sucker

What are they?

Bay tree suckers are sap sucking true bugs that feed on the leaves of bay during the summer months. The winged adults are greenish brown and 2mm long. The nymphs are flat wingless insects, grey in colour and covered in a white fluffy material.

Symptoms

Leaves curl downwards at the edges and turn yellow, generally only half the leaf is affected. These areas then dry and become brown. Uncurling a damaged leaf is likely to reveal a tiny woolly insect with a fluffy cobweb like substance.

Treatment

While bay sucker affects the aesthetics of the plant it won't reduce growth and vigour. Sap sucking insects can be removed by washing affected leaves with water and a couple of drops of washing up liquid. Encourage predators and natural enemies such as birds, ladybirds, wasps and ground beetles. If they still persist pesticides can be used.

Horse Chestnut Scale

What are they?

Horse Chestnut Scale is a sap sucking bug that feeds on trees and shrubs, they are a type of scale insect that many gardeners experience. Adults are up to 5mm long and usually found on the main trunk and branches. During the summer months they drop off leaving clusters of white eggs.

Symptoms

The eggs are generally the first sign of its presence. When they are laid they start to leave a white woolly wax substance, just below the brown shell or scale that covers the insect. It is usually found in urban areas and roadsides where temperatures are higher. While it can look unsightly, there is little harm done to the host plant.

Treatment

These can be removed by scraping off with your fingers and destroying. Affected plants can also be washed with insecticidal soaps. Alternatively, insecticides containing deltamethrin can be used midsummer.

Soft Scale

What is it?

Soft Scale is another type of scale insect. They are flat and oval in shape and yellow/brown in colour with a waxy covering that repels liquids. The adults can be up to 4mm long, the smaller immature nymphs are much smaller.

Symptoms

Plants with an infestation of soft scale exhibit deposits of a clear sticky liquid called honeydew. These deposits attract sooty mould - a black non parasitic fungus - and ants which are usually the first signs of an infestation. Ants will look after the scale insects similar to their behaviour with aphids. They harvest the honeydew for their colony and will move the scale insects to more attractive or uninfected parts of the plants to maximise production, causing more problems for the plant owner.

Treatment

The treatment of soft scale insects is relatively easy providing there are no ants. The ants will need to be brought under control first if they are present as they will protect the soft scale insects by moving them to a safe location. The application of sticky barriers to affected plants will help to rid the ants.

Neem oil or horticultural sprays can be used to rid the plants of scale but will need reapplications to keep numbers low. Where possible, tolerate smaller populations as they will not cause any harm to the plant. Alternatively plant invigorators such as SB Plant Invigorator can be used to promote plant growth with surfactants or fatty acids that have a physical mode of action.

Tortrix Moth Caterpillars

What is it?

Tortrix moth caterpillars are small green caterpillars at the larvae stage of the tortrix moth family. There are nearly 400 species in the UK but only two feed on plants and cause problems in gardens and greenhouses.

Symptoms

The caterpillars roll themselves into leaves creating a shelter by binding them with silky threads and feeding within them. This causes damage to the leaves causing them to dry up and turn brown.

Treatment

Non pesticidal controls include squeezing the leaves of light populations to crush the sheltering caterpillars and pupae and encourage natural predators such as birds, wasps and ground beetles. Pheromone traps are another natural alternative, an open sided box with a pheromone releasing pellet on a sticky base enticing and trapping the male and reducing the mating success of the females. Pesticide sprays are available for control, organic sprays with natural pyrethrum help to control but will require reapplication due to their short persistence.

 

Further Reading

The RHS website has further information of pests and diseases that can affect bay trees: https://www.rhs.org.uk/advice/profile?pid=251