Let’s Plant Ontario Wildflowers

Smooth Blue Aster (Aster à feuilles lisses)

Symphyotrichum laeve

Image of Smooth Blue Aster from the Let's Plant Ontario and Quebec Wildflowers page

Smooth Blue Aster photo courtesy of Let’s Plant

How to germinate

This species has the germination code A, meaning there is no pre-treatment required for the seeds. Please review the online germination code handbook for more information.

How to plant

Outdoor sowing in spring, on a weed-free plot, clear of vegetation is recommended for this plant species. Place seed no deeper than ⅛ inch into the soil and light cover with soil. Gently water after seeds have been sowed.

  • This plant needs full or partial sun exposure in medium-wet, medium, or medium-dry soil.
  • Chelsea Chopped (a pruning method)? Yes
  • Can it be aggressive? No

Characteristics

  • Life cycle: Perennial
  • Height: 4 feet (120 cm)
  • Spread: 1–3 feet (30–90 cm)
  • Bloom time: August–October
  • Bloom colour: Blue
  • Stratification: None

Calico Aster (Aster latériflore)

Symphyotrichum lateriflorum

Image of Calico Aster from the Let's Plant Ontario and Quebec Wildflowers page

Calico Aster photo courtesy of Let’s Plant

How to germinate

This species has the germination code A, meaning there is no pre-treatment required for the seeds. Please review the online germination code handbook for more information.

How to plant

Outdoor sowing in spring, on a weed-free plot, clear of vegetation is recommended for this plant. Plant seeds spaced 18–36 inches apart. 

  • This plant needs full, partial sun exposure or a shaded area in medium-wet, medium, or medium-dry soil.
  • Can it be chelsea chopped? Yes
  • Can it be aggressive? Mildly

Characteristics

  • Height: 5 feet (150 cm)
  • Spread: 2–3 feet (60–90 cm)
  • Bloom time: August–October
  • Bloom colour: White, purple
  • Stratification: None

Common Evening Primrose (Onagre Bisannuelle)

Oenothera biennis

Image of Common Evening Primrose from the Let's Plant Ontario, Quebec, BC, Prairie, and Maritime Wildflowers page

Common Evening Primrose photo courtesy of Let’s Plant

How to germinate

No pre-treatment is required for this species, but the seeds are very small or need light to naturally germinate. This means, the seeds should be surface sown with no soil cover applied, or just a light dusting. This species has the germination code A, D and G. Please review the online germination code handbook for more information.

How to plant

Outdoor sowing between late fall and early spring, on a weed-free plot, clear of vegetation is recommended for this plant.

  • This plant needs full or partial sun exposure and medium-wet, medium, medium-dry, or dry soil conditions. Rocky or sandy soils are recommended. 
  • Can it be chelsea chopped? Yes
  • Can it be aggressive? Yes

Characteristics

  • Life cycle: Perennial
  • Height: 6 feet (180 cm)
  • Spread: 1–2 feet (30–60 cm)
  • Bloom time: June–October 
  • Bloom colour: Yellow
  • Stratification: None

Upland White Goldenrod / Upland White Aster (Verge d’or Faux-ptarmica)

Oligoneuron album / Aster Solidago ptarmicoides

Image of Upland White Goldenrod Upland White Aster from the Let's Plant Ontario and Quebec Wildflowers page

Upland White Goldenrod Upland White Aster photo courtesy of Let’s Plant

How to germinate

No pre-treatments are required for this plant. This species has a germination code A. Please review the online germination code handbook for more information.

How to plant

Outdoor sow at a depth of 1/16 inch between late fall and early spring, on a weed-free plot, clear of vegetation is recommended.

  • This plant needs full sun exposure in medium-dry, dry soil conditions to grow.
  • Can it be chelsea chopped? Yes
  • Aggressive? No

Characteristics

  • Life cycle: Perennial
  • Height: 1–1.5 feet (30–45 cm)
  • Spread: 0.83–1 feet (25–30 cm) 
  • Bloom time: June–September 
  • Bloom colour: White
  • Stratification: None

Sneezeweed (Bois de la toux)

Helenium autumnale

Image of Sneezeweed from the Let's Plant Ontario, Quebec, and Maritime Wildflowers page

Sneezeweed photo courtesy of Let’s Plant

How to germinate

This species has the germination codes A and D. Please review the online germination code handbook for more information.

How to plant

Direct sow on a weed-free plot, at a depth of ⅛ inches. 

  • This plant needs full sun exposure or partial shade and wet or medium-wet soil conditions to grow.
  • Can it be chelsea chopped? Yes
  • Can it be aggressive? No

Characteristics

  • Life cycle: Perennial
  • Height: 4 feet (120 cm)
  • Spread: 2–3 feet (60–90 cm)
  • Blooming time: August–October
  • Blooming colour: Yellow
  • Stratification: None

Mountain Mint (Pycnanthème à feuilles étroites)

Pycnanthemum virginianum

Image of Mountain Mint from the Let's Plant Ontario, Quebec, and Maritime Wildflowers page

Mountain Mint photo courtesy of Let’s Plant

How to germinate

This species has the germination codes A and D.  Please review the online germination code handbook for more information.

How to plant

Outdoor surface sowing in spring, on a weed-free plot, clear of vegetation is recommended for this plant species. Place seeds no deeper than ⅛ inch into the soil, making sure they are not completely buried, just lightly covered. Gently water after seeds have been sowed. 

  • This plant needs full or partial sun exposure and wet, medium-wet, medium, or medium-dry soil conditions to grow.
  • Can it be chelsea chopped? Yes
  • Can it be aggressive? Yes

Characteristics

  • Life cycle: Perennial
  • Height: 3 feet (90 cm)
  • Spread: 1–1.5 feet (30–45 cm) 
  • Bloom time: June–September
  • Blooming colour: White
  • Stratification: None

Hoary Mountain Mint (Menthe des montagnes grises)

Pycnanthemum incanum

Image of Hoary Mountain Mint from the Let's Plant Ontario and Quebec Wildflowers page

Hoary Mountain Mint photo courtesy of Let’s Plant

How to germinate

This species has the germination codes A and D.  Please review the online germination code handbook for more information.

How to plant

Outdoor surface sowing in spring, on a weed-free plot, clear of vegetation is recommended for this plant species. Place seeds no deeper than ⅛ inch into the soil, making sure they are not completely buried, just lightly covered. Gently water after seeds have been sowed.

  • This plant needs full or partial sun exposure and medium, medium-dry soil conditions to grow.
  • Can it be chelsea chopped? Yes
  • Can it be aggressive? Yes

Characteristics

  • Life cycle: Perennial
  • Height: 3–6 feet (90–183 cm)
  • Spread: 1–1.5 feet (30–45 cm)
  • Bloom time: July–September
  • Blooming colour: White, purple
  • Stratification: None

Purple Prairie Clover (Dalée violette)

Dalea purpurea

Image of Purple Prairie Clover from the Let's Plant Ontario, Quebec, and Prairie Wildflowers page

Purple Prairie Clover photo courtesy of Let’s Plant

How to germinate

This species has the germination code A, I, and J. Please review the online germination code handbook for more information. 

How to plant

Direct sow at a depth of ¼ inches or 6 mm into open compact soil. 

  • This plant needs full sun to partial shade, and medium to dry, well-drained soils to grow.
  • Can it be chelsea chopped? No
  • Can it be aggressive? No

Characteristics

  • Life cycle: Perennial
  • Height: 1–3 feet (30–90 cm)
  • Spread: 1.25–1.5 feet (38–45 cm)
  • Blooming time: July–September
  • Blooming colour: Purple
  • Stratification: None

Wild Bergamot (Monarde Fistuleuse)

Monarda fistulosa

Image of Wild Bergamot from the Let's Plant Ontario, Quebec, BC, Prairie, and Maritime Wildflowers page

Wild Bergamot photo courtesy of Let’s Plant

How to germinate

This species has the germination code A, meaning no pre-treatment is required for it. Please review the online germination code handbook for more information.

How to plant

Direct sow on weed-free plot at a depth of ⅛ inches. 

  • This plant needs full or partial sun exposure, and medium-wet, medium, or medium-dry soil conditions to grow.
  • Can it be chelsea chopped? Yes
  • Can it be aggressive? Somewhat, but can be easily contained.

Characteristics

  • Life cycle: Perennial
  • Height: 2–4 feet tall (60–120 cm)
  • Spread: 2–3 feet wide (60–90 cm)
  • Blooming time: July–September
  • Blooming colour: Purple
  • Stratification: None

New England Aster (Aster de la Nouvelle-Angleterre)

Symphyotrichum novae-angliae

Image of New England Aster from the Let's Plant Ontario and Quebec Wildflowers page

New England Aster photo courtesy of Let’s Plant

How to germinate

Most wild plant seeds have built-in dormancy mechanisms that prevent the seed from germinating. To grow these plants anywhere, you  must first break this dormancy mechanism, which will allow the seed to grow. This species has specific germination instructions. It has a germination code of C(60), which means you have to artificially stratify the seeds for 60 days, or sow seeds outdoors in the fall to over-winter naturally to see germination the following spring. Please review the online germination code handbook for more information. 

How to plant

Once stratification is complete, sow the seeds outdoors into rows, ⅝ inches deep into the soil. Ensure the seeds are spaced 30 cm apart. 

  • This plant needs full or partial sun exposure, and wet, medium-wet, medium, or medium-dry soil conditions to grow.
  • Can it be chelsea chopped? Yes
  • Can it be aggressive? No

Characteristics

  • Life cycle: Perennial 
  • Height: At least 5–6 feet (150–180 cm)
  • Spread: 2 to 3 feet wide (60–90 cm) 
  • Bloom time: August–October 
  • Bloom colour: Purple, pink
  • Stratification: Yes

Early Sunflower (Hélopsis Faux-Hélianthe)

Heliopsis helianthoides

Image of Early Sunflower from the Let's Plant Ontario and Quebec Wildflowers page

Early Sunflower photo courtesy of Let’s Plant

How to germinate

Most wild plant seeds have built-in dormancy mechanisms that prevent the seed from germinating. To grow these plants anywhere, you  must first break this dormancy mechanism, which will allow the seed to grow. This species has specific germination instructions. It has a germination code of C(30), which means you have to artificially stratify the seeds for 30 days, or sow seeds outdoors in the fall to over-winter naturally to see germination the following spring. Please review the online germination code handbook for more information. 

How to plant

Once stratification is complete, sow the seeds outdoors into well-weeded, thin rows, 1 inch deep into the soil. Ensure the seeds are spaced 45–90 cm apart. 

  • This plant needs full or partial sun exposure, and sandy, medium-wet, medium, or medium-dry soil conditions to grow. 
  • Can it be chelsea chopped? No
  • Can it be aggressive? No

Characteristics

  • Life cycle: Short-Lived Perennial
  • Height: 5 feet (150 cm)
  • Spread: 2–4 feet (60–120 cm)
  • Blooming time: June–September
  • Blooming colour: Yellow
  • Stratification: Yes

Black-eyed Susan (Rudbeckie Hérissée)

Rudbeckia hirta

Image of Black-eyed Susan from the Let's Plant Ontario and Quebec Wildflowers page

Black-eyed Susan photo courtesy of Let’s Plant

How to germinate

Most wild plant seeds have built-in dormancy mechanisms that prevent the seed from germinating. To grow these plants anywhere, you must first break this dormancy mechanism, which will allow the seed to grow. This species has specific germination instructions. It has a germination code of C(30), which means you have to artificially stratify the seeds for 30 days, or sow seeds outdoors in the fall to over-winter naturally to see germination the following spring. Please review the online germination code handbook for more information. 

How to plant

Once stratification is complete, sow the seeds outdoors into well-weeded, thin rows, ⅛–½ inch deep into the soil. Ensure the seeds are spaced 30–45 cm apart. 

  • This plant needs full or partial sun exposure, and well-drained, medium-wet, medium, or medium-dry soil conditions to grow. 
  • Can it be chelsea chopped? Yes
  • Can it be aggressive? Can become aggressive if there’s not enough competition.

Characteristics

  • Life cycle: Biennial or Short-Lived Perennial
  • Height: 2–3 feet (60–90 cm)
  • Spread: 1–2 feet (30–60 cm)
  • Blooming time: June–October
  • Blooming colour: Yellow
  • Stratification: Yes

Brown-eyed Susan (Rudbeckie Trilobée)

Rudbeckia triloba

Image of Brown-eyed Susan from the Let's Plant Ontario and Quebec Wildflowers page

Brown-eyed Susan photo courtesy of Let’s Plant

How to germinate

Most wild plant seeds have built-in dormancy mechanisms that prevent the seed from germinating. To grow these plants anywhere, you must first break this dormancy mechanism, which will allow the seed to grow. This species has specific germination instructions. It has a germination code of C(30), which means you have to artificially stratify the seeds for 30 days, or sow seeds outdoors in the fall to over-winter naturally to see germination the following spring. Please review the online germination code handbook for more information. 

How to plant

Once stratification is complete, sow the seeds outdoors into well-weeded, thin rows, ⅛–¼ inch deep into the soil. Ensure the seeds are spaced 45–60 cm apart.

  • This plant needs full or partial sun exposure, and medium-wet, medium, or medium-dry soil conditions to grow.
  • Can it be chelsea chopped? Yes
  • Can it be aggressive? No

Characteristics

  • Life cycle: Biennial or Short-Lived Perennial
  • Height: 5 feet (150 cm)
  • Spread: 1–2 feet (30–60 cm)
  • Blooming time: August–October
  • Blooming colour: Yellow
  • Stratification: Yes

Rose Milkweed (Asclépiade incarnate)

Asclepias incarnata

Image of Rose Milkweed from the Let's Plant Ontario, Quebec, Prairie, and Maritime Wildflowers page

Rose Milkweed photo courtesy of Let’s Plant

How to germinate

Most wild plant seeds have built-in dormancy mechanisms that prevent the seed from germinating. To grow these plants anywhere, you must first break this dormancy mechanism, which will allow the seed to grow. This species has specific germination instructions. It has a germination code of C(30), which means you have to artificially stratify the seeds for 30 days, or sow seeds outdoors in the fall to over-winter naturally to see germination the following spring. Please review the online germination code handbook for more information. 

How to plant

Once stratification is complete, sow the seeds outdoors into well-weeded, thin rows, ¼ inch deep into the soil. Ensure the seeds are spaced 45–90 cm apart.

  • This plant needs full or partial sun exposure, and wet, medium-wet, or medium soil conditions to grow. 
  • Can it be chelsea chopped? Yes
  • Can it be aggressive? No

Characteristics

  • Life cycle: Perennial
  • Height: 4–5 feet (120–150 cm)
  • Spread: 2–3 feet (60–90 cm)
  • Blooming time: June–September
  • Blooming colour: Pink
  • Stratification: Yes

Grass-leaved Goldenrod (Verge d’or à Feuilles de Graminée)

Euthamia graminifolia

Image of Grass-leaved Goldenrod from the Let's Plant Ontario and Quebec Wildflowers page

Grass-leaved Goldenrod photo courtesy of Let’s Plant

How to germinate

Most wild plant seeds have built-in dormancy mechanisms that prevent the seed from germinating. To grow these plants anywhere, you must first break this dormancy mechanism, which will allow the seed to grow. This species has specific germination instructions. It has a germination code of C(30), which means you have to artificially stratify the seeds for 30 days, or sow seeds outdoors in the fall to over-winter naturally to see germination the following spring. It also has the germination code D, meaning these seeds are very small and may need light to naturally break the dormancy mechanisms. Please review the online germination code handbook for more information. 

How to plant

Once stratification is complete, surface sow the seeds on the soil, ensuring they are not covered.

  • This plant needs full or partial sun exposure, and wet, medium-wet, medium, medium-dry soil conditions to grow. 
  • Can it be chelsea chopped? Yes
  • Can it be aggressive? Yes

Characteristics

  • Life cycle: Perennial
  • Height: 4–5 feet (120–150 cm)
  • Spread: 1–2 feet (30–60 cm)
  • Blooming time: July–September
  • Blooming colour: Yellow
  • Stratification: Yes

Stiff Goldenrod (Verge d’or Rigide)

Oligoneuron rigidum

Image of Stiff Goldenrod from the Let's Plant Ontario and Quebec Wildflowers page

Stiff Goldenrod photo courtesy of Let’s Plant

How to germinate

Most wild plant seeds have built-in dormancy mechanisms that prevent the seed from germinating. To grow these plants anywhere, you  must first break this dormancy mechanism, which will allow the seed to grow. This species has specific germination instructions. It has a germination code of C(60), which means you have to artificially stratify the seeds for 60 days, or sow seeds outdoors in the fall to over-winter naturally to see germination the following spring. Please review the online germination code handbook for more information. 

How to plant

Once stratification is complete, sow the seeds outdoors into rows, ⅛ inch deep into the soil. Ensure the seeds are spaced 30 cm apart.

  • This plant needs full or partial sun exposure, and medium-wet, medium, medium-dry, or dry soil conditions to grow. 
  • Can it be chelsea chopped? Yes 
  • Can it be aggressive? No

Characteristics

  • Life cycle: Perennial
  • Height: 4–5 feet (120–150 cm)
  • Spread: 1.5–2.5 feet (45–75 cm)
  • Blooming time: August–October
  • Blooming colour: Yellow
  • Stratification: Yes

Early Goldenrod (Verge d’or Jonciforme)

Solidago juncea

Image of Early Goldenrod from the Let's Plant Ontario, Quebec, and Maritime Wildflowers page

Early Goldenrod photo courtesy of Let’s Plant

How to germinate

Most wild plant seeds have built-in dormancy mechanisms that prevent the seed from germinating. To grow these plants anywhere, you  must first break this dormancy mechanism, which will allow the seed to grow. This species has specific germination instructions. It has a germination code of C(60), which means you have to artificially stratify the seeds for 60 days, or sow seeds outdoors in the fall to over-winter naturally to see germination the following spring. It also has the germination code D, meaning these seeds are very small and may need light to naturally break the dormancy mechanisms. Please review the online germination code handbook for more information. 

How to plant

Once stratification is complete, surface sow the seeds ⅛ inch deep into the soil, ensuring they are only lightly covered with soil.

  • This plant needs full or partial sun exposure, and medium, medium-dry, or dry soil conditions to grow. 
  • Can it be chelsea chopped? Yes
  • Can it be aggressive? Yes

Characteristics

  • Life cycle: Perennial
  • Height: 3–4 feet (90–120 cm)
  • Spread: 2–3 feet (60–90 cm)
  • Blooming time: July–September
  • Blooming colour: Yellow
  • Stratification: Yes

Showy Goldenrod (Verge d’or élégante)

Solidago speciosa

Image of Showy Goldenrod from the Let's Plant Ontario and Quebec Wildflowers page

Showy Goldenrod photo courtesy of Let’s Plant

How to germinate

Most wild plant seeds have built-in dormancy mechanisms that prevent the seed from germinating. To grow these plants anywhere, you  must first break this dormancy mechanism, which will allow the seed to grow. This species has specific germination instructions. It has a germination code of C(60), which means you have to artificially stratify the seeds for 60 days, or sow seeds outdoors in the fall to over-winter naturally to see germination the following spring. It also has the germination code D, meaning these seeds are very small and may need light to naturally break the dormancy mechanisms. Please review the online germination code handbook for more information. 

How to plant

Once stratification is complete, surface sow the seeds ⅛ inch deep into the soil, ensuring they are only lightly covered with soil.

  • This plant needs full or partial sun exposure, and rocky or clay soils, with medium, medium-dry, or dry soil conditions to grow. 
  • Can it be chelsea chopped? Yes
  • Can it be aggressive? No

Characteristics

  • Life cycle: Perennial
  • Height: 5–6 feet (150–180 cm)
  • Spread: 2–3 feet (60–90 cm)
  • Blooming time: August–November
  • Blooming colour: Yellow
  • Stratification: Yes

Lance-leaf Coreopsis (Coréopsis lancéolé)

Coreopsis lanceolata

Image of Lance-leaf Coreopsis from the Let's Plant Ontario, Quebec, and BC Wildflowers page

Lance-leaf Coreopsis photo courtesy of Let’s Plant

How to germinate

Most wild plant seeds have built-in dormancy mechanisms that prevent the seed from germinating. To grow these plants anywhere, you must first break this dormancy mechanism, which will allow the seed to grow. This species has specific germination instructions. It has a germination code of C(30), which means you have to artificially stratify the seeds for 30 days, or sow seeds outdoors in the fall to over-winter naturally to see germination the following spring.  Please review the online germination code handbook for more information. 

How to plant

Once stratification is complete, sow the seeds outdoors into well-weeded, thin rows, ⅛ inch deep into the soil. Ensure the seeds are spaced 20–45 cm apart.

  • This plant needs full sun exposure, and medium-dry or dry soil conditions to grow.
  • Can it be chelsea chopped? Yes
  • Can it be aggressive? Yes

Characteristics

  • Life cycle: Perennial
  • Height: 2 feet (60 cm)
  • Spread: 1–2 feet (30–60 cm)
  • Blooming time: May–August
  • Blooming colour: Yellow
  • Stratification: Yes

Showy Milkweed (Belle Asclépiade)

Asclepias speciosa

Image of Showy Milkweed from the Let's Plant Ontario, Quebec, BC, and Prairie Wildflowers page

Showy Milkweed photo courtesy of Let’s Plant

How to germinate

Most wild plant seeds have built-in dormancy mechanisms that prevent the seed from germinating. To grow these plants anywhere, you must first break this dormancy mechanism, which will allow the seed to grow. This species has specific germination instructions. It has a germination code of C(30), which means you have to artificially stratify the seeds for 30 days, or sow seeds outdoors in the fall to over-winter naturally to see germination the following spring.  Please review the online germination code handbook for more information. 

How to plant

Once stratification is complete, sow the seeds outdoors into well-weeded, thin rows, ⅛ inch deep into the soil. Ensure the seeds are spaced 20–45 cm apart.

  • This plant needs full sun exposure, and medium, medium-dry, or dry soil conditions to grow. 
  • Can it be chelsea chopped? Yes
  • Can it be aggressive? Yes

Characteristics

  • Life cycle: Perennial
  • Height: 3 feet (90 cm)
  • Spread: 1–2.5 feet (30–75 cm)
  • Blooming time: June–August
  • Blooming colour: Purple
  • Stratification: Yes

Narrow-leaved Coneflower (Échinacée à Feuilles Étroites)

Echinacea angustifolia

Image of Narrow-leaved Coneflower from the Let's Plant Ontario, Quebec, and Prairie Wildflowers page

Narrow-leaved Coneflower photo courtesy of Let’s Plant

How to germinate

Most wild plant seeds have built-in dormancy mechanisms that prevent the seed from germinating. To grow these plants anywhere, you must first break this dormancy mechanism, which will allow the seed to grow. This species has specific germination instructions. It has a germination code of C(90) and M, which means you have to artificially stratify the seeds for 90 days, and these seeds are best planted outdoors during the fall so they can germinate in the following spring. If premature sprouting occurs, plant immediately. Please review the online germination code handbook for more information. 

How to plant

Once stratification is complete, sow the seeds outdoors into well-weeded, thin rows, ⅛ inch deep into the soil. Ensure the seeds are spaced 30 cm apart.

  • This plant needs full sun exposure, and medium-dry or dry soil conditions to grow. 
  • Can it be chelsea chopped? Yes
  • Can it be aggressive? No

Characteristics

  • Life cycle: Perennial
  • Height: 2 feet (60 cm)
  • Spread: 1–1.5 feet (25–45 cm)
  • Blooming time: June–July
  • Blooming colour: Pink
  • Stratification: Yes