Fiery Fall Gardens

by Brett Kerley

Fall is Edmonton’s most underrated gardening season. Sure, it’s short, but those crisp, sunny days and cool nights can make for some of the most dramatic colour displays of the year — if you plan ahead. With a little intention, you can create a garden that doesn’t just survive into September, but peaks in September and October with fiery foliage, jewel-toned berries, and late-blooming flowers that buzz with life until the first hard frost.

Amur Maple

When you’re planning for autumn impact, think of trees and shrubs as the “bones” of the garden. They set the structure and hold their place year after year, reliably delivering colour.

Amur Maple (Acer ginnala)

• Height & Spread: 4–6 m (13–20 ft) tall and wide, multi-stemmed or trained as a small tree.
• Hardiness Zone: 2 — extremely hardy, perfect for Edmonton.
• Fall Colour: Scarlet to crimson, with orange and burgundy tones mixed in. In Edmonton we have some beautiful Amurs along 97th St. from 137th Ave. to 153rd Ave. Check them out this fall (Griesbach).
• Why It Works: One of the most reliable small trees for northern gardens, drought-tolerant once established.
• Tips for Best Colour: Plant in full sun; slightly dry conditions in late summer can intensify colour. Deep-water before freeze-up for winter health.

Viburnum (V. trilobum, V. dentatum, V. opulus)

• Height & Spread: 2–3 m (6–10 ft) tall and wide.
• Hardiness Zone: 2–3 (variety dependent).
• Fall Colour: Orange-red to wine-red leaves, red or black berries persist into early winter.
• Why It Works: Provides spring flowers, summer green, autumn foliage, and winter bird food.
• Tips: Prefers evenly moist soil; prune immediately after flowering to avoid removing next year’s buds.

Contorted Larch

Larch (Larix laricina & L. decidua)

• Height & Spread: 10–20 m (33–66 ft), pyramidal shape.
• Hardiness Zone: 2 (tamarack) to Zone 3 (European larch).
• Fall Colour: Glowing golden needles before they drop. The Wagner Natural Area has some magnificent Tamaracks, go pay the area a visit.
• Why It Works: Offers four-season interest: soft green spring growth, airy summer shade, blazing autumn colour, and beautiful winter silhouette.
• Tips: Plant where afternoon sun will backlight the needles for maximum effect. Prefers moist, slightly acidic soil. For something with a wow factor why not try a Contorted European Larch (Larix decidua ‘Horstmann’s Recurved’). This small tree is a show stopper and looks weirdly cool. But it does cost a fair bit at around $400-$500.

Honourable Mentions

• Mountain Ash (Sorbus aucuparia): Zone 2; clusters of orange berries + red foliage.
• Chokecherry (Prunus virginiana): Zone 2; deep purple foliage and edible berries.
• Ninebark (Physocarpus opulifolius): Zone 3; burgundy foliage that holds colour until frost.

Your fall garden doesn’t need to be just about leaves dropping — late-blooming perennials keep the beds lively well into October.

Asters (Symphyotrichum spp.)

• Bloom Time: September through October (sometimes until first hard frost).
• Height: 30–120 cm (12–48 in).
• Hardiness Zone:
  
• Varieties to Try:
  
  • Purple Dome – compact, rich violet flowers.
  • Wood’s Pink – soft pink blooms, mildew-resistant.
  • Native smooth aster ( laeve) – pollinator favourite.
• Tips: Pinch back by ⅓ in June for bushier growth. Divide clumps every 2–3 years to keep vigorous.

Sedum ‘Autumn Joy’

Sedum (Hylotelephium spectabile & cultivars)

• Bloom Time: Late August to October.
• Height: 30–60 cm (12–24 in).
• Hardiness Zone:
  
• Varieties to Try:
  
  • Autumn Joy – pink to bronze flowers.
  • Thunderhead – deep wine-red flowers.
  • Neon – brilliant bubblegum pink.
• Tips: Plant in well-drained soil; sedum can flop if soil is too rich. Leave seed heads for winter structure.

Helenium (Helenium autumnale)

• Bloom Time: Late July to September.
• Height: 90–150 cm (36–60 in).
• Hardiness Zone: 3–4 (choose hardy cultivars).
• Colours: Golden yellow, orange, copper, and mahogany.
• Tips: Loves moist soil and full sun; cut back by one-third in early summer to prevent flopping and encourage branching.

Japanese Anemone

Honourable Mentions:

• Japanese Anemone: Zone 4 (try in sheltered microclimates).
• Rudbeckia ‘Goldsturm’: Zone 3; blooms July–September.
• Ornamental Grasses: Feather reed grass (Calamagrostis x acutiflora, Zone 3) provides vertical texture and gold plumes.

Autumn beauty is best when it’s layered. Here’s how to create a garden that feels intentional and dynamic:

• Contrast Warm and Cool: Pair the red blaze of Amur maple with blue-purple asters or ornamental grasses for a painterly effect.
• Berry + Bloom Combos: Highbush cranberry with purple coneflowers (their black seed heads pop against the berries).
• Texture Play: Sedum’s domed flower heads look great with the upright plumes of Karl Foerster
• Succession Planning: Combine early-turning shrubs (Amur maple) with later-turning larch to extend your colour show by several weeks.

• Water Deeply: Give trees, shrubs, and perennials a good soak in late September and October before freeze-up to prevent winter desiccation. If we have a warm dry autumn, I’d even give my trees and shrubs another water in November. Just remember to get rid of any water left in your hoses before it freezes over.
• Mulch for Root Protection: Apply 5–8 cm (2–3 in) of mulch around perennials and shrubs to moderate soil temperature and retain moisture.
• Leave Some Leaves: Fallen leaves create natural mulch and habitat for overwintering beneficial insects.
• Fall Planting: Late August through early October is ideal for planting hardy trees, shrubs, and perennials in Edmonton (as long as the ground isn’t frozen).

With the right plant mix, Edmonton’s gardens don’t just wind down in autumn — they blaze with colour right up to the first snow. Planting for fall interest not only makes your garden spectacular, but also supports pollinators and wildlife when they need it most.

From tamarack gold to cranberry red — let’s paint Edmonton gardens prairie-chic this fall!