Plant Identification, Selection, and Use
The Plant Identification, Selection, and Use domain tests whether you can name a plant correctly, describe its requirements, and place it where it will still fit in twenty years. Questions cover botanical nomenclature, hardiness and site matching, native and invasive status, mature size, and the design principles that make a planting read as intentional rather than accidental.
Naming rules
- Genus and specific epithet are italicized: Acer rubrum. The cultivar goes in single quotes, is not italicized, and is capitalized: Acer rubrum 'October Glory'.
- Botanical variety uses italic var. followed by the epithet. Because cultivars are clonal, their habit and colour are predictable, which is why designers specify them.
Selection criteria
- Match the plant's native habitat to the site: light levels, moisture regime, soil pH and texture, drainage, exposure to wind and salt, pollution tolerance.
- Check the hardiness zone (Natural Resources Canada zones 0-9) but remember microclimate: a sheltered south wall can run a zone warmer, a low frost pocket a zone colder.
- Size the mature plant, not the nursery plant: canopy spread against overhead conductors and eaves, root spread against foundations and services, and shrub spread against walkways.
- Confirm native or ecosystem value, invasive status, disease susceptibility in your region, and actual supplier availability.
Design use
- Apply unity, balance, proportion and scale, rhythm and a clear focal point, and layer the planting: canopy, understory, shrub, herbaceous, groundcover.
- Repeat a limited palette rather than one of everything; group in odd numbers for naturalistic beds.
Worked example
A 1.5 m boulevard strip, full sun, a 2.8 m overhead conductor and winter road salt. Silver maple is wrong on three counts: mature size, aggressive surface roots and weak wood. The correct choice is a compact, salt-tolerant shrub or small tree that matures below 2.5 m; verify the cultivar's zone, salt rating and supplier stock before it enters the plant list.
Traps that cost marks
Selecting from a flower photo without checking habit; quoting a zone while ignoring microclimate; specifying an invasive species; misspelling scientific names on an identification question.