Construction: plant material verification and installation

CVC staff planting plant material at Our Lady of Fatima Catholic School in Brampton, Ontario. (Photo Source: CVC, 2022)

A healthy and vibrant vegetation structure provides itself with nutrients to sustain growth. Additionally, it holds, and retains water and oxygen, and binds and degrades pollutants. When selecting plants, consider the following:

• Native species need fewer inputs and are better adapted to local climate and soils.
• Larger plant stock should be considered and prioritized in areas of frequent ponding and concentrated flows.
• Trees, shrubs, grasses, sedges and/or rushes present unique benefits and limitations in LID facilities. For example, debris from trees/shrubs may block outlets, but their size and form of planting can provide superior establishment in challenging locations.
• Planted plants in a moderately diverse cluster of plants are more easily maintained and more visually accepted and pleasing to the general public.
• A planting plan should include species that tolerate harsh conditions (e.g., drought, water inundation and/or salt). Most riparian plant species will do well in rain gardens, bioswales and bioretention facilities.
  

Tree guards used at Haggert Ave bioswale in Brampton, Ontario. (Photo Source: CVC, 2019)

During installation:

• Time of planting: It is crucial for plant survival and thriving, avoid at all times planting during summer months with higher temperatures (July and August) and winter months (November - March). Consider planting early in the spring (April - June) or late in the fall (September - October).
• Planting depth: Plant each plug/tree or shrub to the desired depth as per design considerations. For small plants, it is recommended to use small tools such as a hand trowel.
• Plant substitution: Any changes in the species delivered during construction must be accepted by the designer and/or supervision team before installing.
• Trees/Shrubs protection: If any trees/shrubs need protection, ensure that they receive it by installing proper tree guards.
• Irrigation: It is recommended for the plant material to receive additional watering right after planting if no rainfall event occurs. Also, plant material should be watered during the summer months or during drought periods for two years after planting.
• Fertilizers: The use of these products is acceptable, as long as they are applied properly.
• Pesticides: It is recommended to only use if needed.

For more information regarding plant selection, refer to Plant lists and Plant selection.

Credit Valley Conservation

Low Impact Development. A stormwater management strategy that seeks to mitigate the impacts of increased urban runoff and stormwater pollution by managing it as close to its source as possible. It comprises a set of site design approaches and small scale stormwater management practices that promote the use of natural systems for infiltration and evapotranspiration, and rainwater harvesting.

Linear bioretention cell designed to convey, treat and attenuate stormwater runoff. The engineered filter media soil mixture and vegetation slows the runoff water to allow sedimentation, filtration through the root zone, evapotranspiration, and infiltration into the underlying native soil.

A shallow excavated surface depression containing prepared filter media, mulch, and planted with selected vegetation.

Linear bioretention cell designed to convey, treat and attenuate stormwater runoff. The engineered filter media soil mixture and vegetation slows the runoff water to allow sedimentation, filtration through the root zone, evapotranspiration, and infiltration into the underlying native soil.

Human application of water to agricultural or recreational land for watering purposes. City of Toronto Wet Weather Flow Management November 2006 47