Dahlias are herbaceous perennials celebrated for their stunning, vibrant blooms, making them a favorite in gardens and floral arrangements across the USA. Native to Mexico and Central America, they belong to the Asteraceae family, alongside sunflowers and daisies.
Their flowers range in size from 2 to 12 inches and come in nearly every color except true blue, offering endless variety for gardeners. Dahlias bloom from mid-summer to the first frost, providing long-lasting color in beds, borders, and containers.
Originating in the highlands of Mexico, dahlias were cultivated by the Aztecs for food, medicine, and ornamentation before Spanish explorers introduced them to Europe in the 16th century. By the 19th century, European breeders developed thousands of cultivars, sparking global popularity. In the U.S., dahlias gained prominence through early 20th-century horticultural efforts, and today, they’re a staple in American gardens, valued for their diversity and ease of cultivation in various climates.
Dahlias are characterized by their diverse flower forms, including single, double, cactus, pompon, and waterlily types, with petals ranging from flat to tightly rolled or fringed. Plants vary in height from 1 to 7 feet, with sturdy stems supporting lush, green foliage. Their tubers, resembling sweet potatoes, store energy, enabling regrowth each year. In colder U.S. regions (USDA zones 2-7), tubers are lifted and stored overwinter, while in milder zones (8-11), they can remain in the ground.
Yellow Dahlias
Kelvin Floodlight
- Description: A dinnerplate dahlia with massive, fully double blooms reaching up to 10-12 inches in diameter. Its soft lemon-yellow petals are slightly curved, creating a radiant, rounded flowerhead. Ideal for cut flowers and garden focal points.
- Identifying Characteristics: Large, pale lemon-yellow blooms; sturdy stems up to 4 feet tall; formal decorative form with tightly packed petals; blooms mid-summer to frost.
Yellow Star
- Description: A cactus dahlia with spiky, tubular petals in a bright, golden-yellow hue. Blooms are medium-sized, about 6-8 inches, with a starburst effect, adding drama to borders and arrangements.
- Identifying Characteristics: Narrow, rolled petals radiating outward; vivid gold color; plant height of 3-4 feet; blooms late summer to fall; cactus form with pointed tips.
Bumblebee
- Description: A miniature ball dahlia with small, perfectly rounded blooms about 2-3 inches across. Its buttery-yellow petals form a tight, spherical shape, ideal for containers or front borders.
- Identifying Characteristics: Compact, ball-shaped blooms; soft butter-yellow color; dwarf plant reaching 2-3 feet; blooms mid-summer to frost; uniform, dense petal arrangement.
Mary’s Jomanda
- Description: A ball dahlia with medium-sized, 4-6 inch blooms in a warm, golden-yellow shade. The fully double flowers are tightly packed, offering a pompon-like appearance, perfect for bouquets.
- Identifying Characteristics: Spherical, gold-yellow blooms; slightly flattened top; plant height of 3-4 feet; blooms mid to late summer; ball form with layered petals.
Buttercream
- Description: A semi-cactus dahlia with creamy yellow blooms, about 6-8 inches wide, blending soft pastel tones with a hint of ivory. Petals are partially rolled, creating a spiky yet elegant look.
- Identifying Characteristics: Creamy yellow to ivory petals; semi-rolled tips; plant height of 4-5 feet; blooms late summer to fall; semi-cactus form with a softer appearance.
Sunshine
- Description: An anemone-flowered dahlia with bright, sunshine-yellow blooms, 4-6 inches across. It features a central disc of tubular florets surrounded by flat, ray-like petals, adding texture to gardens.
- Identifying Characteristics: Central yellow disc with single outer petal ring; vivid yellow hue; plant height of 3-4 feet; blooms mid-summer to frost; anemone form with contrasting textures.
Golden Scepter
- Description: A formal decorative dahlia with large, 8-10 inch blooms in a rich, golden-yellow shade. Petals are broad and slightly curled, forming a symmetrical, full flowerhead, ideal for exhibitions.
- Identifying Characteristics: Deep golden-yellow color; broad, flat petals; plant height of 4-5 feet; blooms mid to late summer; formal decorative form with uniform petals.
Lemon Puff
- Description: A collarette dahlia with 4-5 inch blooms featuring a single layer of lemon-yellow outer petals and a ruffled collar of smaller, pale yellow inner florets. Its open structure attracts pollinators.
- Identifying Characteristics: Lemon-yellow outer petals; pale yellow collarette; central yellow disc; plant height of 3-4 feet; blooms mid-summer to fall; collarette form with layered effect.
Yellow Happiness
- Description: A waterlily dahlia with medium-sized, 6-8 inch blooms in a soft, buttery-yellow hue. Petals are broad, slightly cupped, and layered, resembling a water lily, perfect for elegant arrangements.
- Identifying Characteristics: Buttery-yellow, layered petals; symmetrical, shallow bloom; plant height of 3-4 feet; blooms late summer to frost; waterlily form with a delicate, open structure.
Canary Fubuki
- Description: A semi-cactus dahlia with 6-8 inch blooms in a bright canary-yellow shade. Petals are partially tubular, curving outward, creating a spiky, dynamic appearance suitable for bold garden displays.
- Identifying Characteristics: Bright canary-yellow color; semi-rolled, pointed petals; plant height of 4-5 feet; blooms mid to late summer; semi-cactus form with radiant spikes.
Mellow Yellow
- Description: A single-flowered dahlia with 4-6 inch blooms featuring a single layer of soft, pale yellow petals surrounding a golden central disc. Its simplicity makes it a favorite for naturalistic gardens.
- Identifying Characteristics: Pale yellow, flat petals; prominent golden disc; plant height of 2-3 feet; blooms mid-summer to fall; single form with open, pollinator-friendly structure.
Goldalia
- Description: A pompon dahlia with small, 2-3 inch blooms in a deep golden-yellow hue. The perfectly spherical flowers are tightly packed, resembling tiny balls, ideal for edging or small arrangements.
- Identifying Characteristics: Deep golden-yellow, spherical blooms; compact, dense petals; dwarf plant reaching 2-3 feet; blooms mid-summer to frost; pompon form with uniform shape.
Yellow Gem
- Description: An orchid-flowered dahlia with 4-6 inch blooms in a vibrant, sunny-yellow shade. Petals are rolled backward, creating a star-like, exotic appearance, adding flair to borders and bouquets.
- Identifying Characteristics: Sunny-yellow, backward-curving petals; open, star-shaped bloom; plant height of 3-4 feet; blooms late summer to fall; orchid form with unique petal curl.
Sunny Boy
- Description: A ball dahlia with 4-6 inch blooms in a bright, lemon-yellow hue. The fully double flowers are tightly packed, offering a rounded, cheerful look, perfect for garden beds and cut flowers.
- Identifying Characteristics: Lemon-yellow, spherical blooms; uniform, dense petals; plant height of 3-4 feet; blooms mid to late summer; ball form with a vibrant, sunny appearance.
Yellow Wizard
- Description: A laciniated dahlia with 6-8 inch blooms in a rich, golden-yellow shade. Petals are fringed and split at the tips, creating a feathery, textured effect, ideal for dramatic floral displays.
- Identifying Characteristics: Golden-yellow, fringed petals; split, feathery tips; plant height of 4-5 feet; blooms late summer to frost; laciniated form with intricate petal structure.
General Notes:
- Bloom Season: Most yellow dahlias bloom from mid-summer (July) to the first frost (October-November), depending on the U.S. region and climate (USDA zones 8-11 for overwintering, lifted in colder zones).
- Growth Requirements: Dahlias prefer full sun, well-drained, fertile soil (pH 6.5-7.0), and regular watering. Stake taller varieties like Kelvin Floodlight to support heavy blooms.
- Uses: These dahlias are popular for garden borders, containers, cut flowers, and exhibitions due to their diverse sizes (2-12 inches) and forms (e.g., decorative, cactus, ball).