15 Flowering Plants With Large Blooms

Tree Peony (Paeonia suffruticosa)

​Peonies with bomb-type flowers make a statement in the spring garden, but tree peonies can sport blooms up to ten inches across on woody stems that do not die back to the ground in winter. Tree peonies like the 'Mrs. Fry' cultivar are slow to mature, but a 5-foot tree peony with 50 blooms is spectacular and worth waiting for. Deeply divided foliage adds to the character of these plants. 

• USDA Hardiness Zones: 4 to 8
• Color Varieties: White, red, pink, purple, yellow
• Sun Exposure: Full sun to part shade
• Soil Needs: Fertile loam, well-drained

Oriental Poppy (Papaver orientale)

These fiery red poppies go by the moniker 'Goliath'. Oriental poppies send long tap roots into the soil, helping them establish a long life in your spring garden. Blooms in excess of 7 inches in diameter are not unheard of. To pamper your poppies, full sun and excellent drainage are the most important requirements. 

• USDA Hardiness Zones: 3 to 7
• Color Varieties: Orange, red, pink, purple, white, peach, maroon, salmon
• Sun Exposure: Full sun
• Soil Needs: Fertile, well-drained soil with average moisture

Hydrangea (Hydrangea spp.)

In the world of hydrangea hybridizing, the big blooms just keep getting better. This genus of plants has several species commonly used in landscaping, all of which are famous for having large flowers. For example, Hydrangea arborescens 'Annabelle' has 12-inch flower heads that are a stunning staple in many shade gardens. However, 'Incrediball' has increased in popularity because it also blooms on new wood but its stems will not flop under the weight of rain-soaked blooms. In addition to the cultivars of H. aborescens, varieties of H. macrophylla, H. serrata, H. paniculata, and H. quercifolia are all known for their impressive blooms.

A sheltered site with some shade will help your hydrangeas shine throughout the growing season. 

• USDA Hardiness Zones: 3 to 9 (depends on species)
• Color Varieties: Blue, pink, white, red, purple
• Sun Exposure: Full sun to part shade
• Soil Needs: Rich, porous, rich soil; pH can affect bloom color of some species

Dinner-plate Dahlia (Dahlia hybrids)

The classification term dinner-plate dahlia is used to describe any dahlia variety with large, impressive flowers measuring at least eight inches across. Most commercially available dinner-plate dahlias are hybrid cultivars. If you have successfully grown dahlias in the past, your quest to grow dinner-plate cultivars like 'Belle of Barmera' or 'Lady Darlene' will be easy. Like many large flowers, dahlias like more of everything: more sun, more water, more feeding. Remove side buds to enable plants to direct their energy into producing a few giant flowers. Stake plants for support, and expect the blooms to mature in late summer. 

• USDA Hardiness Zones: 8 to 11; grown as an annual in colder climates
• Color Varieties: White, pink, red, yellow, cream, orange, purple, maroon; solid and bi-colors
• Sun Exposure: Full sun (some afternoon shade helps in very warm climates)
• Soil Needs: Moist but not soggy, rich, well-draining soil

Giant Water Lily (Nymphaeaceae Genera)

The plants known as water lilies include about 70 species within at least five different genera. They are found across the world, but those most often sold commercially are tropical species. Most species have fairly large flowers, but those known as giants have genuinely enormous blooms and leaves. For example, the night-blooming flowers of Victoria amazonica strive to keep up with its incredible ten-foot leaves, which can support a small person's weight. Its basketball-sized flowers only live for a few days to carry out their reproductive destiny.

Although you cannot cultivate this plant in a typical water garden, you can admire healthy examples of the giant water lily in botanical gardens like Longwood Gardens in Pennsylvania. 

• USDA Hardiness Zones: 10 to 11 (V. amazonica)
• Color Varieties: White to pink/purple
• Sun Exposure: Full sun
• Soil Needs: Submerged rich loam

Orienpet Lily (Lilium Orania)

Hybrids of trumpet and Oriental lilies, orienpet lilies are increasing in popularity as new cultivars continually hit the market. Their large fragrant blooms appear in late summer on sturdy five-foot stems. Try 'Big Brother', a pale yellow variety that lives up to its name with 15 inch blooms.  Like most lilies, orienpet lilies are best planted in late fall or early spring. In neutral or alkaline soils, watering with an acid-enhanced fertilizer will help them thrive.

• USDA Hardiness Zones: 5 to 9
• Color Varieties:  White, yellow, pink, apricot, burgundy, red, and bi-colors
• Sun Exposure: Full sun to part shade
• Soil Needs: Medium-moisture, well-drained soil; thrives in slightly acidic soil

Amaryllis (Hippeastrum group)

Red amaryllis blooms are popular to grow for the winter holidays, but this plant comes in a number of colors and forms. Larger bulbs produce larger plants and flowers, so splurge on premium bulbs from trusted vendors. 'Double Record' with red and white streaking will produce eight-inch flowers for indoor enjoyment. The amaryllis bulbs sold commercially are cultivars derived from hybrids of various Hippeastrum species, developed over many years. Amaryllis is best grown in a relatively cool room (60 to 65 degrees Fahrenheit) with bright, indirect lighting.

• USDA Hardiness Zones: 8 to 10; normally planted as an annual, even in warm climates because a winter chilling period is required
• Color Varieties: Red, pink, white, salmon; solid, striped, and bi-colored
• Sun Exposure: Full sun to part shade
• Soil Needs: Humusy, well-drained potting soil; rich, well-drained soil when planted in the garden

Common Sunflower (Helianthus annuus)

Sunflowers might very well set the standard for giant blooms in the flower garden, but not all sunflowers are created equal when it comes to size. 'Mammoth' is an heirloom variety that reliably produces 12-inch flower heads packed with oil-rich seeds. 'Sunzilla' is a newer hybrid bred to grow a sturdy 16-foot stalk capable of supporting the giant blooms. Although sunflowers are drought-tolerant, constant moisture and rich soil will yield the largest flowers. 

• USDA Hardiness Zones: these are true annuals in all climates
• Color Varieties: Yellow, cream, gold, white, maroon, brown; bi-color and solid
• Sun Exposure: Full sun
• Soil Needs: Average, moist, well-drained

Hardy Hibiscus (Hibiscus moscheutos)

The common potted hibiscus plants are tropical species that won't tolerate even a whiff of frost, but exotic flower lovers can rejoice—the hardy mallow plant Hibiscus moscheutos will survive zone 4 or 5 winters while still boasting flower diameters in excess of ten inches. Some varieties feature bronze or purple foliage to boost the ornamental value. The gorgeous pink-flowered 'Summer Storm' has a dark magenta eye.  In cold regions, use mulch or straw to protect the roots, especially when the plants are young.

• USDA Hardiness Zones: 4 or 5 through 9
• Color Varieties: White, red, pink
• Sun Exposure: Full sun
• Soil Needs: Well-drained loam

Moonflower (Ipomoea alba)

Only night owls will be able to appreciate the nocturnal blooms of the moonflower vine, which swirl open at dusk to reveal six-inch white flowers. Blooms stay open all night. If you nick or soak the seeds, germination can occur in as little as a week. Combine the fast-growing vines with morning glories, and you will please hummingbirds and hummingbird moths alike. 

• USDA Hardiness Zones: 10 to 12; usually grown as an annual
• Color Varieties: White
• Sun Exposure: Full sun
• Soil Needs: Tolerates any soil type

English Rose (Rosa hybrids)

If roses have not been your go-to choice for large blooms in the past, it is time to get acquainted with English roses—a class of roses developed from heirloom varieties by breeder David Austin with the goal of large, full blooms with a heavy fragrance. With petal counts of 140 or more per bloom, these large-cupped flowers are vase-fillers with old-world fragrance to spare. The lemon-hued 'Charles Darwin' and the 200-petal count 'Spirit of Freedom' are repeat bloomers, yielding six-inch flowers all season. Roses can be prone to fungal diseases in moist and humid conditions, so give them plenty of air circulation and avoid wetting the foliage when irrigating them.

• USDA Hardiness Zones: 4 to 11 (varies, depending on variety)
• Color Varieties: White, yellow, red, pink, orange; solid and bi-colors
• Sun Exposure: Full sun
• Soil Needs: Well-drained loam

King Protea (Protea cynaroides)

Protea plants lend an exotic flair to any tropical flower arrangement, and king protea (Protea cynaroides) plants produce the largest flower heads of them all. Also known as sugar bush, these South African natives can be grown outdoors as evergreen shrubs in USDA hardiness zones 9 and warmer. The artichoke-like flowers can grow up to one foot across. Make sure to water the plants deeply on a weekly basis for the first two years; after this, they are relatively low-maintenance plants.

• USDA Hardiness Zones: 9 to 12
• Color Varieties: Red, pink, creamy white
• Sun Exposure: Full sun
• Soil Needs: Average to rocky very well-drained soil; prefers acidic soil

Cockscomb (Celosia argentea var. cristata)

The otherworldly coral shapes of cockscomb Celosia argentea var. cristata make it a garden focal point, but add to that the velvety texture and footlong size, and you have a staple for the cut flower garden. Cockscomb plants are easy to grow from seed (they self-seed readily), and they tolerate humidity as well as dry soil. 

• USDA Hardiness Zones: 2 to 11; normally grown as an annual
• Color Varieties: Orange, red, purple, yellow, pink
• Sun Exposure: Full sun
• Soil Needs: Rich, moist, well-drained soil; tolerates dry soil

Butterfly Bush (Buddleia davidii)

A single flower panicle of Buddleia davidii can grow up to 18 inches in length, with each panicle comprised of hundreds of densely packed florets. The nectar-rich flowers will attract an endless parade of butterflies over its bloom cycle, which usually stretches into four months. Beware of the possibility of rampant spreading; this plant is known to be invasive in some regions if not deadheaded.

• USDA Hardiness Zones: 5 to 9
• Color Varieties: Purple and pink are common; yellow, and red cultivars are also available
• Sun Exposure: Full sun
• Soil Needs: Average, well-drained soil

Camellia (Camellia spp.)

For southern gardeners, there is nothing quite like the charm of a camellia bush in the late winter garden. For the biggest flowers, plant a cultivar of the Camellia japonica species. Disbudding will help you achieve six-inch flowers on varieties like the double pale pink Camellia japonica 'Debutante' which is hardy in USDA hardiness zones 8 through 10.

• USDA Hardiness Zones: 7 to 9 (Camellia sinensis)
• Color Varieties: White, pink, red, yellow, lavender
• Sun Exposure: Filtered sun, part shade
• Soil Needs: Consistent moisture, acidic, well-drained soil