Arctic Fire dogwood tree, approximately 3 years old, planted in very large planter, full sun.
In the last 2 days, the dogwood has developed grey shrivelling leaves on random branches. What is this and how can I treat it? Thanks
Thanks for reaching out to Toronto Master Gardeners about the grey, shrivelling leaves appearing on your Arctic Fire dogwood, also known as a red twig dogwood or a red osier dogwood. The scientific name is Cornus sericea ‘Farrow’ ARCTIC FIRE.
This plant performs best in part-shade to full sun and in medium to wet soil. A container plant growing in full sun can be susceptible to both leaf scorch and drought stress and that is likely what is happening to your shrub.
Cut back the discoloured leaves with clean clippers. It may help to move your dogwood out of the midday sun. If the container is too large to move, you can cover it with a mesh cover designed to protect plants from harsh sunlight. Or if the container is close to a heat source, such as a barbecue, try to move it as far away as possible.
You may need to water your shrub more often and more deeply. This is particularly important because this type of dogwood has a shallow root system. Check the moisture level of your soil daily with your finger. If the soil feels dry, water the plant well. If the soil feels moist, don’t water and check it again the following day. Some container plants require daily or even twice daily watering during the summer months.
Your dogwood would benefit from adding compost in the early spring and then topping that with a layer of leaf or wood mulch. Try to avoid using black mulch as it holds the heat in. Mulch will help suppress weeds, moderate soil temperature, retain moisture and add organic matter to your soil as it breaks down.
For more information about common diseases in dogwoods, here is a link to The Missouri Botanical Garden
Here’s another link to common dogwood diseases from Penn State
Happy gardening!
May 31, 2024