Shrubs and trees can be damaged by herbicides in two ways. Herbicide drift results in damage to the leaves of contacted plants downwind of the spray. Herbicides applied to weeds around the base of a tree or shrub may also end up poisoning those plants. Key Points Plants can be damaged two ways by herbicide, [...]
Many animals leave their signs on trees. Squirrels, voles and porcupines may chew off bark for food or medication. Sapsuckers (a type of woodpecker) drill holes in thin-barked trees such as birch to drink tree sap and eat the insects attracted to the ooze. Honeysuckles and other shrubs with shredding bark may be stripped by [...]
Mulch is defined as “A protective covering, usually of organic matter such as wood chips, straw, or peat, placed around plants to prevent the evaporation of moisture, the freezing of roots and the growth of weeds”. Key Points The recommended depth for mulch is 2 to 4 inches. Always keep mulch several inches away from [...]
This disease of hawthorns and juniper shrubs is becoming more common. The disease requires two hosts to complete its life cycle (Juniper and Hawthorn). The symptoms look very different in the two host species. Key Points Minor infestations may look objectionable but cause little damage to the Hawthorn tree Chemical controls may be possible using [...]
Normally our summers are too dry for the development of Fire blight, but in 2008 our spring and early summer were warm and wet enough to result in rapid spread of the disease. Since then we have seen the disease randomly affect Hawthorn, Mountain Ash, Pear, Crab Apple, Apple and Cotoneaster. This bacterial disease can [...]
This fungal disease affects many Poplar and Aspen species. Both Tower Poplar and Swedish Columnar Aspen are highly susceptible to the disease, which is unfortunate due to the number of these trees in Calgary. Bronze Leaf Disease affects only Poplars but not all poplar species are susceptible. Fungal Spores are transferred by air causing infection [...]
