Gardening in a changing climate

Sirman observes that apple maggots have appeared in her area only within the past few years. Scientists with Natural Resources Canada, Canadian Forest Service, believe climate change will cause “prolonged, severe outbreaks of spruce budworm in increasingly higher latitudes and elevations.” Valleau doesn’t know if there are new pests or just more of the usual culprits, such as aphids and leafhoppers, which are vectors for spreading viruses. “We’re seeing more perennials with viruses, but whether any of this is attributable to climate change is another matter. We don’t really know.”

Many of the plants we grow can adapt to changing conditions, as can gardeners. “In the end, homeowners need to deal with their yards on an individual basis,” says Sirman. “There are many factors at play in plant survival—not just climate.”

Sustainable plants
Gardening in a changing climate calls for a greater reliance on plants that can adapt to extreme conditions. Here’s a list of some of the toughest ones.

Drought-tolerant perennials

• Common thrift (Armeria maritima) Zone 2
• Alpine sea holly (Eryngium alpinum) Zone 2
• Blazing star (Liatris spicata) Zone 2
• Russian sage (Perovskia atriplicifolia) Zone 5
• Verbascum (Verbascum spp. and hybrids) Zones 3 to 5

5 heat-tolerant perennials

• Fern-leaf yarrow (Achillea filipendulina) Zone 2
• False indigo (Baptisia australis) Zone 2
• Butterfly bush (Buddleja davidii) Zone 5
• Blanket flower (Gaillardia x grandiflora hybrids) Zone 2
• Orange coneflower (Rudbeckia fulgida) Zone 3

5 moisture-loving perennials

• Black Scallop bugleweed (Ajuga reptans ‘Binblasca’) Zone 4
• ‘Gold Heart’ bleeding heart (Dicentra spectabilis ‘Gold Heart’) Zone 3
• Common foxglove (Digitalis purpurea) Zone 5
• ‘Britt-Marie Crawford’ bigleaf ligularia (Ligularia dentata ‘Britt-Marie Crawford’) Zone 4
• ‘Chocolate Wings’ featherleaf rodgersia (Rodgersia pinnata ‘Chocolate Wings’) Zone 5

—with files from Judith Adam

Read more in What to do now and Jobs in the Garden by Season