Are you checking this article out so you can find a remedy to a disease that is already trying to kill your plants? Or are you checking it out so you can be a GP to you trees in the future?
Either way, while plants and trees are wonderful, they are also suspectable to diseases and death if not treated. Below are the most common diseases we get asked about. Symptoms and solutions for you.
- Blight – Commonly found in manuka (Kanuka is resistant to blight).
Symptoms: Discoloured and wilted leaves and shoots which may easily snap or fall off tree. Often a black or brown covering over the leaves and stems.
Solution: Remove and affected leaves and twigs from tree and destroy them to prevent further spread. Apply fungicide to the blight affected area. And ensure the tree(s) has a good amount of water and nutrients as stress makes plants more - Borer - Borer is a small brown beetle, but it is the larvae that cause the most damage. A small white-ish worm looking larvae that eat through wood. They can be found in any woody plant such as hornbeams, and it doesn't even have to be alive, they are known to eat through any sort of untreated wood.
Symptoms: Smallish holes on trunk or branches, which is often accompanied by sawdust at the base of the tree.
Solution: Spray and insecticide (such as 'No Borer') on all affected areas of the tree, you may need to do this more than once over a few weeks to ensure the insecticide is still active and is doing what it is supposed to. It's also a good idea check around other nearby trees for signs of borer. - Canker – Common in trees of the Leyland type. Canker is one of the most untreatable of diseases (at least on this list) . Canker occurs when an infection gets into a ‘wound’ on the tree or its leaves, it develops quickly over spring. Unfortunately there is no chemical or easy remedy that can cure canker.
Symptom: Diseased branches which will have discoloured bark, wilted leave and may appear to have distorted growth. A visible sunken lesion may be present on the trunk or branches.
Solution: The best way to deal with this is chop off all affected areas, this is the only way to stop it spreading. It is best to disinfect the chopping tool between each cut. Try to reduce stress on the tree, making sure it has enough water and nutrients. Spraying a fungicide such as copper oxychloride, on the trunk and branches will possibly help fight the infection. - Thrips – this is common on Viburnum. It is a tiny insect, about 1 millimetre long that sucks the contents in the leaves. Like mites. they reproduce very quickly, especially in warm weather, meaning they can cover an entire plant or hedge with a few days or weeks.
Symptoms: Silvery streaks or dots on leaves, as well as distorted leaf growth. Discoloured and wilted leaved that may fall of the plant.
Solution: If you spot it early enough, Thrips may be controlled by snipping the worst affected areas out of the shrub/tree. Insecticides sprays such as Confidor which you can buy from local stores such as Mitre 10, are the best at eliminating Thrips. The main ingredient (imidacloprid) is taken in by the plants and when the insect congests the treated plant, they soon die. The reason that we suggest you add oil to the mix is that it makes it hard for the Thrips to attach to the plant, as it is too slippery.
If you can’t see any symptoms matching this list when diagnosing you’re plants, then it could be 1001 other things. Is the soil too wet or too dry? Has the plant been frosted? Too much coastal/salt wind? There are endless amount of diseases and reasons that your plants could suffer from. A quick google or a call to your local nursery maybe able to help you.
As the old saying goes, prevention is better than cure so it's best to choose plants that are resistant to disease and suited to the environment you are planting them in. And check them every now and then to spot for early signs of disease.