Hawthorn Trees in Ontario — Native Species & Care
Native hawthorn species for every Ontario zone — from Ottawa (Zone 4) to Windsor (Zone 7) — edible berries, wildlife hedgerow value, and why cockspur hawthorn is the best native shrub you're probably not growing.
Hawthorn in Ontario at a glance
All of Ontario (Zone 4–7): Washington hawthorn (Zone 3-8) and cockspur hawthorn (Zone 3-6) grow reliably province-wide. Multiple native species are also available. Ottawa and eastern Ontario (Zone 4): fully hardy without protection — both species are Zone 3. Toronto to Windsor (Zone 5b–7): full ornamental range including 'Paul's Scarlet' double-pink flowers. All zones: edible haws ripen in September–October and persist through winter, feeding cedar waxwings and robins.
Will hawthorn thrive where you garden?
Check your hardiness zone and your city's exact frost dates first — two free tools.
Native Hawthorn Species in Ontario
Ontario has several native hawthorn species — choosing one supports the local ecology in ways that imported ornamental varieties cannot. Native species evolved alongside Ontario's birds, bees, and butterflies; the flowering and fruiting times are timed to local wildlife needs.
Cockspur Hawthorn — Crataegus crus-galli (Zone 3–6)
The most common native hawthorn in Ontario. Distinctive flat-topped form, very long thorns (7–10 cm), white flower clusters in May, dull red berries persisting through winter. Excellent orange-red fall colour. Mature size: 4–6 m wide and tall. Thornless cultivar 'Inermis' available for gardens where thorns are a concern.
Best use: Wildlife hedgerow, property boundary, naturalized areas. Provides the best wildlife value of any Ontario hawthorn — dense nesting habitat, long-persistent berries.
Fleshy Hawthorn — Crataegus succulenta (Zone 2–6)
Native across Ontario and very cold-hardy. Large, fleshy red berries — the best-tasting native Ontario hawthorn for making jelly and syrup. White flowers in May–June. Mature size: 3–5 m.
Best use: Edible berry production, wildlife planting, prairie and meadow gardens. If you want to harvest haws for food in Ontario, this is the species to plant.
Washington Hawthorn — Crataegus phaenopyrum (Zone 3–8)
North American native (not Ontario-native but a great ornamental choice). The most spectacular ornamental hawthorn for Ontario gardens: white flowers in late May, glossy orange-red berries developing by August, brilliant orange-red fall foliage rivalling any maple. Berries persist through February or March.
Best use: Specimen tree or large shrub. Mature size 6–10 m. The complete three-season ornamental package — flowers, berries, fall colour — that most garden trees can't match.
Hawthorn by Ontario Zone
Zone 4b–5a — Ottawa, Kingston, Barrie, Sudbury
Eastern and northern Ontario winters are no challenge for hawthorn — most species are Zone 3. Hawthorn is one of the few flowering trees that genuinely thrives at this latitude without winter protection.
Recommended:
- Washington hawthorn — three-season ornamental display, fully Zone 3 hardy
- Cockspur hawthorn — native, flat-topped form, persistent red berries
- Fleshy hawthorn — native, large edible haws, Zone 2 hardy
- Fireberry hawthorn — truly Zone 2, for the coldest northern Ontario sites
Skip: 'Paul's Scarlet' (C. laevigata) is Zone 5 — marginal in Ottawa and not recommended for Zone 4 gardens.
Zone 5b–6a — Toronto, Hamilton, Kitchener, London
The Greater Toronto Area supports the full range of hardy hawthorns plus the ornamental European varieties. This is the zone where 'Paul's Scarlet' blooms reliably — double crimson-pink flowers in May make it the showiest of all hawthorns.
Recommended additions to the Ottawa list:
- 'Paul's Scarlet' — double crimson-pink flowers, most ornamental hawthorn
- 'Crimson Cloud' — single deep-red flowers with white star centre
- Black hawthorn (C. douglasii) — grows in this zone, dark purple-black berries
Zone 6b–7 — Windsor, Niagara, St. Catharines
The warmest zone in Ontario. All hawthorn species and ornamental varieties grow reliably. Washington hawthorn reaches its most impressive size here — trees can reach 8–10 m with a broad canopy covered in white flowers and then blazing orange-red berries and fall foliage. 'Paul's Scarlet' blooms freely every year.
Hawthorn is an excellent alternative to ornamental pear trees (which are invasive) for four-season interest in Windsor and Niagara gardens.
Ontario Growing Tips
Planting time
Spring after last frost (mid-May in Toronto, late May in Ottawa) or fall (September). Fall planting is excellent for hawthorn — the roots establish well before freeze-up and the tree experiences less transplant shock than spring planting in summer heat.
Soil tolerance
Hawthorn is one of the most soil-tolerant trees for Ontario gardens. It grows in clay soils common to the GTA, alkaline soils of southern Ontario limestone country, and dry sandy soils once established. No soil amendment needed for a native species — dig a hole, plant it, water through the first season.
Fire blight
Hawthorn can be susceptible to fire blight (a bacterial disease affecting the Rosaceae family) in wet Ontario springs. Look for blackened, wilted shoot tips that look scorched. Prune infected wood 30 cm below the visible damage with sterilized pruners. Resistant varieties like Washington hawthorn are less affected.
Common Questions — Hawthorn in Ontario
Is cockspur hawthorn native to Ontario?
Yes — Crataegus crus-galli (cockspur hawthorn) is native throughout southern Ontario into Quebec, growing naturally in hedgerows, forest edges, and open areas. It is one of the most ecologically valuable shrubs you can plant in an Ontario garden. The native provenance means it evolved with Ontario's pollinators and birds, supporting species that rely on it for food and nesting in ways that introduced ornamental varieties cannot.
Can I grow 'Paul's Scarlet' hawthorn in Ottawa?
'Paul's Scarlet' (C. laevigata) is Zone 5 — Ottawa is Zone 4b–5a, so it is marginal. In a sheltered south-facing position you might succeed, but cold winters will damage or kill it. For guaranteed flowering hawthorn in Ottawa, Washington hawthorn (Zone 3) gives you white flowers and a much better ornamental package overall: better berries, better fall colour, fully Zone 3 hardy. Washington hawthorn is the better choice for Ottawa gardens.
How do I make hawthorn jelly from Ontario haws?
Harvest haws in late September or October after the first frost when berries are fully coloured and slightly soft. Rinse, cover with water (equal parts berries to water), bring to a boil and simmer 20 minutes until soft. Strain through cheesecloth overnight — don't squeeze or the jelly will be cloudy. Measure the juice, add equal volume of sugar and a package of pectin, bring to a hard boil, skim foam, jar immediately. Yields a clear, garnet-coloured jelly with a mild apple-rose flavour.
What hawthorn species are native to Ontario?
Several hawthorn species are native to Ontario. Cockspur hawthorn (Crataegus crus-galli) is one of the most widespread — it grows naturally across southern Ontario into Quebec, with a distinctive flat-topped form and very long thorns (up to 10 cm). Fleshy hawthorn (C. succulenta) grows across Ontario and produces large red berries that are excellent for jelly and syrup. Quebec hawthorn (C. submollis) is native to eastern Ontario and Quebec with large red haws. Fireberry hawthorn (C. chrysocarpa) extends into northern Ontario, where it is genuinely Zone 2 hardy. Planting any of these native species supports local pollinators and provides food for birds that evolved alongside these plants.
Which hawthorn is best for Ottawa vs Toronto?
For Ottawa (Zone 4b–5a): Washington hawthorn (C. phaenopyrum, Zone 3-8) and cockspur hawthorn (C. crus-galli, Zone 3-6) are both excellent and fully hardy. Native fireberry and fleshy hawthorn also survive Ottawa winters without protection. Avoid 'Paul's Scarlet' (C. laevigata, Zone 5) in Ottawa — it is marginal at Zone 4b and may suffer in a cold winter. For Toronto (Zone 5b–6a): the full ornamental range is available — 'Paul's Scarlet' blooms reliably here, Washington hawthorn puts on a spectacular show, and native cockspur hawthorn is excellent as a specimen or hedgerow plant. Toronto gardens can also support 'Crimson Cloud' and other midland hawthorn varieties.
When do hawthorn berries ripen in Ontario?
Hawthorn berries ripen in Ontario from September through October. In southern Ontario (Toronto, London, Windsor), most species are fully coloured by mid-September. In Ottawa and northeastern Ontario, ripening is complete by early October. After the first frost (typically October in southern Ontario, September-October in Ottawa), the berries soften slightly and improve in flavour — this is the best time to harvest for jelly or syrup. Many species hold their berries through winter into February or March. Cedar waxwings, American robins, and other birds rely heavily on persistent hawthorn berries during winter and early spring when other food sources are gone.
Can I use hawthorn as a privacy hedge in Ontario?
Yes — hawthorn makes one of the most effective natural barriers available. Cockspur hawthorn (C. crus-galli) with its long, sharp thorns creates an impenetrable hedge that no person or animal will push through. Plant 60–90 cm apart for a dense hedge. It takes 5–8 years to reach full density but requires little maintenance once established. For a garden-friendly hedge without thorns, thornless cockspur ('Inermis') offers the same structure, white flowers, and fall berries without the hazard. Hawthorn hedges also provide nesting habitat for birds — far more ecological value than a cedar hedge or fence.
Do hawthorn trees attract wildlife in Ontario?
Exceptionally well. Hawthorn is among the most wildlife-valuable trees you can plant in an Ontario garden. In May and June, the flower clusters attract bees, beetles, and other pollinators. Through summer, the dense thorny structure provides protected nesting sites for songbirds — robins, song sparrows, cedar waxwings, and catbirds all nest in hawthorn. In fall and winter, the persistent berries feed cedar waxwings, American robins, and northern mockingbirds. A mature hawthorn can support dozens of bird species across the seasons — it functions as a complete habitat plant, not just an ornamental.
Find Your Ontario Frost Dates
Know your last spring frost to time hawthorn planting, and your first fall frost to plan your haw harvest.
Use the Frost Date Calculator →