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Pest and Disease of Bay Laurel Tree (page 4)

Bay Laurel is normally a healthy plant suffering from few pests and diseases.

When grown in pots though, they often suffer from an irregular water supply. Keeping them regularly watered is especially important in dry conditions. Browning leaves are often a sign of lack of water.

Bay trees can also be affected by hard frosts when they are grown in pots. The best plan is to move them near the house in winter. The house walls will lessen the effect of frost and protect them from harsh winds.

The technical term is trioza alacris, the common name is jumping plant lice (or louse)! The first signs are of leaves curling around the margins. Parts of the affected leaves then turn yellow. Finally the leaves will turn brown at the edges. The leaves finally fall off. This is often not fatal to the bay tree but it certainly weakens the tree leaving it open to other pests and diseases.

The best treatment for Bay Sucker is to keep an eye out for signs of damage so that it can be treated early on. Look out for those yellowing leaves which will also be thicker than normal where affected. When they are noticed, pick them off and burn them. Spray the under sides of all leaves with a very diluted washing up liquid solution.

If the damage is more severe you need to understand the cause. The bay sucker is a tiny insect about 2mm long which over-winters in nooks and crannies, often in the soil surrounding your bay tree. Breaking up the surface of the very top of the soil surrounding the plant to a fine tilth will help expose the pests, especially in the winter.

In mid April the first generation of Bay Suckers will appear and these will feed on the sap of your bay tree. They then lay even smaller eggs on the underside of the leaves, almost invisible to the naked eye. They can often be seen more clearly through a magnifying glass. These eggs also feed on the sap increasing the damage. They multiply quickly and often three generations worth can be seen on badly affected plants.

One pesticide works reasonably well if applied early on, it is thiacloprid. Have a look on the internet for products which contain this pesticide. be aware though, that this is a systemic pesticide and it will therefore remain present in the leaves for a couple of weeks (consult the package instructions). The leaves should not be used whilst the pesticide remains.




Name: jim@GardenAction
Date posted: December 21, 2011 - 03:55 pm
Message: Sounds like a sooty mould, a fungal infection.

Name: Mrs S Griffiths
E-mail: Private
Date posted: December 21, 2011 - 09:37 am
Message: Baytree leaves are black it looks like soot but sticky, it will wipe off, but very difficult to shift identical tree the other side of front door is fine with no problems

Name: jim@GardenAction
E-mail: Private
Date posted: November 15, 2011 - 05:43 pm
Message: A problem. Bays are evergreen. Would suggest it was not watered enough.

Name: brian
E-mail: Private
Date posted: November 15, 2011 - 02:17 pm
Message: my bay tree has droped all its leaves. can i spray tree with a fungicide thanks brian

Name: Magaret
Date posted: September 28, 2011 - 08:40 am
Message: My Bay tree is infested with flies, wasps and spiders. The branches are covered with black soot and there are raised yellow/brown spots on the underside of the leaves.

Name: Maggie
E-mail: Private
Date posted: September 25, 2011 - 11:17 am
Message: The leaves on my laurel tree have been eaten by something and are turning brown. There is also a pungent smell coming from the tree. Is there anything that I can do?

Name: Lexi Dick
Date posted: September 14, 2011 - 05:15 pm
Message: I have the answer for Victoria who has problems with ants. You need to discourage them, as they are farming the scale insects for honeydew. On my balcony, where I have many bay trees, I tried ant poison, and co-existing (this was disastrous - I had ants everywhere).

In the end, I worked out that if I stamped on every ant I saw, they would stop coming to my balcony. I think that if more than a certain percentage of ants fail to return to the nest, more will not be sent out. In a confined area, this works like a charm.

Name: Marian Prowse
E-mail: Private
Date posted: August 18, 2011 - 08:14 am
Message: My bay tree is covered in flies. I have only noticed it this year. Is there anything I should be doing? Grateful for any advice.

Name: Neveah
Date posted: August 07, 2011 - 03:28 pm
Message: This forum needed skihang up and you've just done that. Great post!

Name: Tiffany smith
Date posted: August 01, 2011 - 05:53 am
Message: I have 2 bay trees that have been eaten by something and have brown leaves and holes all over the leaves. One of them is now growing lots of new leaves but I have noticed that these are also being eaten. I cannot spot any caterpillars or anything that could be doing this? How can I stop this? What can I use? Bewildered!

Name: Andreas
Date posted: July 20, 2011 - 04:50 am
Message: My Laurel is suffering from an Ant Attack! Any idea's of how to get rid of them please?

Name: nikki
Date posted: July 02, 2011 - 05:02 pm
Message: my bay has got whte fungus at the bottom of the stems and the leaves are turning yellow what can i do about this thank you

Name: lorna
Date posted: June 27, 2011 - 08:59 am
Message: my bay tree has lost most of its leaves and the few that remain d. I repotted it earlier in the year. Could I have over watered it and can I prune tree right back to encourage new growth? thank you.

Name: j bradbury
Date posted: June 20, 2011 - 04:59 am
Message: the bark is coming off from our 10 year old bay tree, any idea's anyone?

Name: L Beecroft
E-mail: Private
Date posted: June 16, 2011 - 06:54 am
Message: My bay tree has black lumps and white fungus on the trunk and black spots on the leaves. Please could you advise me.

Date posted: June 14, 2011 - 03:09 pm
Message: My bay tree has a white fungus on the trunk and main branches. Can you tell me what it is and how I can clear it up please.

Name: David Seaton
E-mail: Private
Date posted: June 11, 2011 - 02:57 pm
Message: My Bay Laurel is about 15 ft high and nearly all leaves still brown after the severe winter.The stems appear green when I peel the bark. Will it make new leaves? any advice? Should I prune it?

Name: Randall
Date posted: June 08, 2011 - 07:28 am
Message: I have a bay tree which is an established tree(20 yrs old) but has recently developed white spots around the trunk and branches possibly fungal. Can anybody please offer me some advise?

Name: chris
E-mail: Private
Date posted: June 06, 2011 - 06:54 am
Message: I have a bay tree which has been fine for a few years but has recently developed white spots around the trunk possibly fungal. can anybody please offer me some advise?

Name: kurt
Date posted: June 03, 2011 - 01:19 pm
Message: I have a potted bay leafed tree about four feet high. In winter I bring inside. This year I lost track on watering it and a few weeks ago I brought it out side. Now about all the leaves are brown but the trunks are still green I water and keep in a shaded area. I think the sun was to hot when o brought it out and lack of water may have contributed to this condition. Will it regrow new leaves thanks