6. Leaf Spot
Along with anthracnose, there are a number of ailments often called “leaf spot” that may trigger spots or areas of discoloration to develop on the leaves, and all of those could cause the foliage to drop.
Fungi in each the Cercospora and Septoria genera trigger recognizing.
Within the case of Cercospora leaf spot, the areas are tan or gentle brown with reddish-purple borders. There is likely to be a chlorotic, pale yellow border round them, as properly.
Spots attributable to Septoria are grey with a brown border.
When the foliage is closely symptomatic, the leaves will drop from the plant. You’ll want to handle the trigger to cease the falling foliage.
Each thrive in humid, wet situations when it’s heat.
Spray the tree with fungicide as quickly as you discover signs. Copper, sulfur, or thymol are all tried-and-tested choices.
I all the time maintain copper fungicide in my gardening toolkit because it’s helpful for treating so many various plant ailments.
Bonide Copper Fungicide
You will discover copper fungicide accessible at Arbico Organics. It lasts longer in mud type than liquid, and also you merely combine it with water everytime you want it.
Observe the producer’s instructions for utility and proceed to spray all through the season.
7. Midges
Clubgall midges (Resseliella clavula) trigger ugly galls in your dogwood.
The adults are tiny flies with orange abdomens and black and yellow wings, however these aren’t harmful. It’s the larvae that it is advisable to be careful for.
After the females lay eggs within the springtime within the creating twig buds, the maggots that hatch feed on the plant materials and their saliva causes a protecting gall to type, defending the larvae to allow them to feed and develop.
The galls could cause the twigs to die and the leaves on it to fall to the bottom. The remainder of the leaves on the tree will sometimes stay wholesome.
They feed all summer time after which emerge within the fall, chewing their method out of the galls. The larvae then drop to the bottom and overwinter in plant particles earlier than pupating in spring.
When the larvae are current and hiding out within the galls, you’ll be able to’t do a lot about them until you wish to prune off every one. There may be dozens on a single tree, so this could be a problem.
The opposite choice is to spray within the spring to kill the adults and once more within the fall to kill the younger as they emerge.
Bonide Captain Jack Deadbug Brew
A product like Bonide’s Captain Jack Deadbug Brew which is accessible at Arbico Organics is efficient.
Spray on a windless day within the spring and once more within the fall once you see holes showing within the galls. Ensure to spray the bottom across the tree too!
8. Nitrogen or Iron Deficiency
Dietary deficiencies can even trigger leaf drop in dogwoods.
When it’s an absence of nitrogen that’s the issue, the older leaves will first flip pale inexperienced or pale yellow earlier than they drop.
Iron deficiency reveals up in newer leaves, usually turning them yellow, whereas the veins stay inexperienced. They’ll ultimately drop from the tree as properly.