Monitor for needlecast and blight diseases on older foliage where new foliage is emerging on PINE and SPRUCE.
Diplodia tip blight on Austrian pine
Snowball aphid damage on Viburnum.
Populations of Aphids are starting to really take off this spring on greenhouse and outdoor ornamentals. They are loving the softer tissue from this cool spring. Usually aphids are not life threatening to woody plants, but they can stunt growth and they are unsightly to consumers.
Seeing holes in leaves on deciduous trees? This sugar maple was showing interveinal holes and closer inspection revealed fall cankerworm (Alsophila pometaria) larvae on the leaf undersides. Larvae are pale green (although you’ll often see darker races too) and blend in with newly emerged foliage. They are only about 5-8 mm long right now but oye, can they eat! Continue reading
May 24 is here! And here’s some advice from the Farmer’s Almanac:
“When you do get attacked by black flies, there are a number of things you can do to soothe the itch:
- Wash the affected area with soap and warm water
- Avoid scratching the bites as much as possible. Scratching can break the skin, increasing the risk of infection.
- Apply a topical agent, such as aloe vera, witch hazel, or a gentle over-the-counter remedy, such as calamine lotion, which can also help. If the itching persists, or is very bad, an antihistamine cream may be needed.”
Remember this? This is what apple scab did to many of our older, susceptible crabapple cultivars in 2017. Protect new growth of Malus before leaf wetness periods. (This is a REMINDER summary of the post from April 20, 2018)
Look for small, white, woolly tufts or masses on the twigs of hemlock (Tsuga canadensis) (Photos: Julie Holmes, CFIA). It is still a good time to scout for Hemlock Woolly Adelgid (Adelges tsugae) because of the visibility of the white covering on the egg masses. It is not a common pest in Ontario, in fact it has been found Continue reading
Gymnosporangium rusts are sporulating now on Juniperus hosts. Look for orange, gelatinous structures on foliage and stems of various Juniperus spp. They are sporulating both in container production and in the field. They can be found sporulating when the Cercis canadensis (redbud) begin to bloom, unless it is too dry.
Monitor for Gymnosporangium rusts such as Cedar-apple rust (above) Continue reading