Is that Plant Easy-Going or Is It Super-Fussy?

We already know it’s important to match plant to place, making sure it’s suited to the conditions it will be growing in. When we have “right plant, right place”, the plant is more likely to thrive without much input from us.

But did you know there are some scientific measures to help us? These numbers help tell us how fussy a plant is. Does it need certain conditions or is it easy-going and happy wherever we put it?

Here are three things we look for here at Grounded to help us create plantings that succeed.

Wetland Indicator Status

Wetland Indicator Status is a classification system that categorizes plants according to their probability of occurrence in wetlands versus uplands.

There are five designations, going from plants that must have wet feet to plants that must have dry feet… and everything in between.

Obligate Wetland: Lobelia cardinalis (Cardinal Flower) – Almost always occurs in wetlands, typically found along stream banks, wet meadows, and swamps.

Cardinal Flower needs to keep its feet wet.

Facultative Wetland: Iris versicolor (Blue Flag Iris) – Usually occurs in wetlands, but occasionally found in non-wetlands.

Facultative: Monarda fistulosa (Wild Bergamot) – Equally likely to occur in wetlands and non-wetlands, adaptable to a range of moisture conditions. It’s the least fussy!

Facultative Upland: Solidago rigida (Stiff Goldenrod) – Usually occurs in non-wetlands, but occasionally found in wetlands; typically prefers drier, well-drained soils.

Obligate Upland: Baptisia australis (Blue Wild Indigo) – Almost always occurs in non-wetlands, requiring well-drained soils and showing no tolerance for wetland conditions.

Heliophily Index

Heliophily Index is a quantitative measure of a plant’s preference for and physiological adaptation to sunlight exposure, with higher values indicating sun-loving species and lower values representing shade-tolerant plants. For example:

Low (index of 3): Carex pensylvanica (Pennsylvania Sedge) – A shade-tolerant species adapted to filtered light conditions.

Medium (5): Penstemon digitalis (Foxglove Beardtongue) – Adaptable to both partial shade and sun conditions. Very easy-going!

Foxglove Beardtongue is happy in partial shade and sun.

High (8): Sporobolus heterolepis (Prairie Dropseed) – A sun-loving species adapted to open prairie conditions with full exposure.

Coefficient of Conservatism

Coefficient of Conservatism is a numerical value (typically 0-10) that indicates a plant species’ ecological sensitivity and fidelity to specific intact natural habitats.

In other words, how easy-going or fussy is it?

Higher numbers represent specialized species of high-quality ecosystems; lower numbers represent disturbance-tolerant generalists.

Here are some examples:

Low (1): Symphyotrichum novae-angliae (New England Aster) – A disturbance-tolerant generalist that readily adapts to various conditions. That’s easy going for you!

Medium (5): Echinacea purpurea (Purple Coneflower) – A moderately conservative species found in both intact and somewhat disturbed habitats.

Butterfly Milkweed will only thrive if the conditions are right.

High (9): Asclepias tuberosa (Butterfly Weed) – A highly conservative species typically found only in high-quality, undisturbed natural habitats. Beware: this plant wants conditions that are just right.