Red Alder Fungus in Cones

Fungal Diseases of Red Alder Cones

• The same fungi that affect the catkins of the red alder also affect the cones. Taphrina occidentalis and Taphrina alni are the two most common fungi to infect the cones and catkins of the red alder. Disease caused by Taphrina spp. is identified by the hypertrophied or enlarged galls and bracts on the female cones and catkins. The enlargement of the bracts of the catkins hinders and even prevents normal fertilization and seed development.

Treatment of Fungus in Cones

• Generally, the presence of Taphrina occidentalis or Taphrina alni does not pose a significant threat to the red alder, and the diseased cones can be removed by hand or left alone and allowed to take their course. However, the presence of the disease throughout large stands of trees, especially those grown commercially or for seed, may be cause for concern. If you are concerned that the fungus is overtaking the cones and catkins on your tree or trees, homemade sprays containing baking soda, garlic oil or hydrogen peroxide may be used. When using baking soda, mix 5 tablespoons into a quart of water. For garlic oil, use 5 drops per quart of water; and for hydrogen peroxide spray, mix 1 ounce of hydrogen peroxide with 8 ounces of water. For best results when using baking soda or garlic oil, add a couple of drops of natural biodegradable soap to the water. Pour mixtures into spray bottles and spray directly onto cones and catkins. Avoid getting hydrogen peroxide on your skin to prevent burning.

Other Fungal Diseases of Red Alders

• A number of fungal diseases can infect the red alder, especially if the tree is damaged or suffering from decay. One such disease is called red heart rot and is usually caused by the fungus Stereum sanguinolentum. The most deadly fungal disease to affect the alder is white heart rot caused by Phellinus igniarius. Both diseases result in wood stain and wood decay. Black knot can also be an issue for the red alder, causing black galls to form on the branches.

Tips for Growing Healthy Red Alders

• Two of the biggest threats to the health of the red alder are drought and frost damage, making cold, dry winters a real danger for them. Frost damage makes them more susceptible to fungal disease. During periods of low rainfall, they should be watered to compensate for the drought conditions. Red alders require at least 25 inches of precipitation a year, especially if they do not have access to ground water. If planting red alder trees from seeds, soak the seeds for 24 hours. Then drain and dry them well and store them in the refrigerator for up to six weeks in a freezer bag. Plant them in well-drained or sandy loam. New plantings should be well watered and weeded frequently. They should not be transplanted after the end of their second year.