Common Tree Illnesses And How To Treat Them

Trees contribute very much to a landscape’s benefit, so it’s crucial to keep them healthy. Here’s how to handle 10 of the most typical tree illness.


Anthracnose is a common disease among deciduous trees, specifically sycamore, ash and oak. It likewise affects shrubs such as privet. It triggers unattractive dark, sunken lesions on leaves, stems, flowers and fruits.

Some cultural practices can help prevent it, including collecting and disposing of leaves and branches, as well as increasing air flow by pruning contaminated branches when the tree is inactive. Caring for your trees will help them grow rapidly and fill out your backyard.

Apple Scab

Apple scab is a typical disease of apple and crab apple trees, as well as mountain ash and pear. Leaf spots are olive green at first, later turning dark brown to black.

It’s best to plant a variety that is resistant to apple scab. Talk to your regional cooperative extension office for scab-resistant apple ranges matched to your environment. You can help lessen apple scab in future years by raking and dealing with leaves before winter. Fungicides will not work on infected trees however can prevent apple scab on healthy trees. Timing is essential.

Canker Diseases

A range of canker diseases affect trees, including Cytospora canker on pine, poplars, spruce and willows. Canker illness result when a fungal or bacterial pathogen gets in bark or sapwood through a wound. Ultimately the tree’s vascular system becomes obstructed and nutrients can not flow. Depending on where the canker is, this clog can cause branches to die. If it’s twisted around the trunk, the entire tree may not survive.

Trees That Are Stressed

From ecological elements, animal surfing, mechanical injury, etc., are most susceptible. Preventive measures consist of growing trees matched to the available space and conditions, avoiding injury to bark, correct upkeep and winter protection, and getting rid of any branches impacted by canker. Sanitize pruning tools in between cuts with a 10 percent bleach solution.

Cedar-Apple Rust

As the name implies, cedar-apple rust is a fungus that requires 2 hosts to complete its life process: cedar (Juniperus spp.) and apple and crab apple (Malus spp.). An associated fungi, cedar-hawthorn rust, contaminates hawthorn trees.

The fungus spends its first year on the cedar. The following spring, spores are brought by wind and infect the 2nd host, typically located within a number of hundred feet but in some cases approximately a mile away.

The disease triggers intense yellow-orange spots on leaves and fruit, and swollen fruiting bodies on stunted branches. Leaves and fruit might drop too soon. One cultural control is to plant a variety with resistance to cedar-apple rust (consult your regional cooperative extension for recommendations). Or spray a fungicide in spring before symptoms establish. Several applications are required.

Diplodia Tip Blight

Blight can impact several tree species, but this illness prevails on stressed out conifers, especially Austrian pine. New development is stunted, turns yellow and after that brown, ultimately passing away. Trees under tension are more vulnerable to diplodia suggestion blight, so keep them mulched and watered, specifically during dry periods. Remove and ruin infected cones and tips, in addition to dead or dying branches, decontaminating pruning tools between cuts with rubbing alcohol or a 10 percent bleach solution. Fungicides are used 3 times in spring: when buds initially break, when brand-new shoots (called candles) are half emerged and once again when they are fully developed.

Dothistroma Needle Blight

Dothistroma needle blight can be deadly and is most typical with Austrian pine and Ponderosa pine. Preventive procedures consist of ensuring excellent air blood circulation by preventing crowding, as well as mulching trees and watering them at the base to prevent wetting foliage.

Fire Blight

Fire blight leaves a telltale calling card: tree branches that look like they’ve been burnt by fire, and wilting leaves that turn black. Fire blight contaminates twigs sporadically, so you may see dead foliage on various locations of the plant. It’s most active in warm, wet weather. To manage fire blight, get rid of and destroy contaminated branches, making sure to cut all the way back to uninfected wood. Disinfect pruning tools between cuts in a 10 percent bleach option. Fruit trees are a prime victim of fire blight, but there are steps you can take to keep your fruit trees healthy.

Oak Wilt

Oak wilt is a fungal disease particular to oak trees. It is deadly to species at a loss oak group (pointy leaf lobes), while those in the white oak household (rounded leaf lobes) are less prone. Beginning at the top of the tree, leaves quickly wilt and turn brown. Oak wilt is passed from tree to tree through the roots of one oak tree to another, or by sap-sucking beetles who are brought in to newly cut wood. Avoid pruning oak trees throughout the growing season. If you need to prune an oak throughout the growing season, use a tree wound sealant to make the injury less attractive to beetles. Appropriately taking care of your oak trees will make sure a spectacular fall foliage.

Powdery Mildew

Powdery mildew is simple to spot due to the powdery white coating covering foliage. Eventually leaves become distorted, turn yellow and drop prematurely. Brought on by a fungi, it is most often discovered on plants in shady areas, particularly when there’s a lot of humidity however no rain.

To manage, avoid planting prone plants such as crape myrtle and lilac; select resistant ranges instead. Give existing plants excellent air circulation also. Plants can likewise be treated with a fungicide.

Phytophthora Root Rot

Phytophthora root rot is a fungal illness that assaults trees growing on poorly drained pipes sites. Prevent planting trees in damp areas or near downspouts. Never ever plant trees much deeper than they grew at the nursery. Plant at the exact same level or slightly greater is preferable. Also avoid piling soil against the trunk.

Consult a good tree service company with certified arborists such as Riverside Tree Service for further assistance with keeping your landscape vibrant and healthy.