20 Tall Flowers That Make a Strong Impact

Several flowering annuals and perennials are tall enough for the back of a garden bed and bold enough to make a statement. Tall flowers help to add structure and depth to a garden bed. They also can be used as a living privacy fence or to hide an unattractive backdrop. Plus, because they're so large you'll be able to see them from afar, as opposed to small flowering plants that you can only appreciate up close.

Here are 20 tall annual flowers and perennial blooms, listed in ascending order (shortest to tallest) that will make strong statements in your garden.

Warning

Some flowers may be toxic to animals or humans, as noted below.

01 of 20
Floss Flower

The Spruce / Marie Iannotti

Floss flowers (Ageratum houstonianum) can reach around 2 1/2 feet high with a 6- to 18-inch spread. They produce clusters of fluffy blooms from June until frost. These plants are easy to grow as long as they have even soil moisture with good drainage. Deadheading (removing the spent blooms) is not necessary for continued blooming but it will make for a tidier appearance. Frost will quickly kill the plants in the fall. In addition, extremely hot summer weather might limit blooming.
- Name: Floss flower (Ageratum houstonianum)
- USDA Growing Zones: 2 to 11 (annual)
- Color Variations: Blue-purple, pink, red, white, bicolor
- Sun Exposure: Full sun to part shade
- Soil Needs: Average, moist, well-drained
- Mature height: 2 1/2 ft.
- Blossoming period: Early summer until frost
02 of 20
Hollyhock Mallow

The Spruce / Evgeniya Vlasova

Hollyhock mallow (Malva alcea) grows to around 2 to 4 feet tall with a spread of less than 2 feet. It features five-petal flowers that stretch around 2 inches across and bloom in the summer to early fall. Butterflies love the flowers. To promote more blooming, remove the spent flower spikes. While it brings lots of ornamental value, this perennial does tend to be short-lived. But it can self-seed fairly well to produce new plants.
- Name: Hollyhock mallow (Malva alcea)
- USDA Growing Zones: 4 to 7
- Color Variations: Pink
- Sun Exposure: Full sun to part shade
- Soil Needs: Medium moisture, well-drained
- Mature height: 2-4 ft.
- Blossoming period: Summer, early fall
03 of 20
Monkshood

The Spruce / Autumn Wood

Monkshood (Aconitum napellus) has an upright growth habit, reaching around 2 to 4 feet tall with a 1- to 1 1/2-foot spread. Clusters of small, hooded blooms arise in the summer above the dark green foliage. This plant needs moist but not soggy soil, and its soil also never should dry out. It doesn’t have any serious issues with pests or diseases. However, all parts of the plant are severly toxic to humans and animals, so take care when working with it.
- Name: Monkshood (Aconitum napellus)
- USDA Growing Zones: 3 to 7
- Color Variations: Blue-purple
- Sun Exposure: Full sun to part shade
- Soil Needs: Rich, moist, well-drained
- Mature height: 2-4 ft.
- Blossoming period: Summer
04 of 20
Red Hot Poker

The Spruce / Evgeniya Vlasova

Red hot poker (Kniphofia uvaria), also known as torch lily, provides unique visual interest to the garden. Its small, tubular flowers arise on spikes above the blue-green basal foliage in the late spring to early summer. They start as red but mature to yellow. The plant itself grows to around 3 to 4 feet high with a slightly smaller spread. Red hot poker is fairly easy to maintain. But it’s important to watch out for poor drainage, as soggy soil can kill it.
- Name: Red hot poker (Kniphofia uvaria)
- USDA Growing Zones: 5 to 9
- Color Variations: Red/yellow
- Sun Exposure: Full sun
- Soil Needs: Average, medium moisture, well-drained
- Mature height: 3-4 ft.
- Blossoming period: Late spring, early summer
Continue to 5 of 20 below
05 of 20
Tall Verbena

The Spruce / Kara Riley

Tall verbena (Verbena bonariensis), sometimes known as Brazilian vervain, is an unusual plant that forms a low clump of leaves and then sends up tall, bobbing stems with clusters of flowers. It can grow to around 4 feet tall and blooms from summer to fall. The plant is excellent at attracting butterflies to the garden, and it can tolerate many soil types as long as there is good drainage. The plant tends to self-seed throughout the garden, so you must be on top of removing seedlings if you want to limit its spread.
- Name: Tall verbena (Verbena bonariensis)
- USDA Growing Zones: 7 to 11
- Color Variations: Pink-purple, lavender
- Sun Exposure: Full sun to part shade
- Soil Needs: Average, moist, well-drained
- Mature height: 4 ft.
- Blossoming period: Summer, fall
06 of 20
Foxglove

The Spruce / Evgeniya Vlasova

Foxglove (Digitalis purpurea) generally reaches around 2 to 4 feet tall, though it occasionally can hit 5 feet. The flower spikes arise from a rosette of foliage at the plant’s base in the late spring. Several long, tubular blooms are grouped on the spikes, which attract hummingbirds to the garden. This perennial is short-lived and won’t produce flowers until its second year. It also can look a bit ragged by the late summer. Thus, many gardeners remove their foxglove plants after they’ve flowered and released their seeds for new plants. Foxglove is toxic to humans and animals.
- Name: Foxglove (Digitalis purpurea)
- USDA Growing Zones: 4 to 8
- Color Variations: Pink, purple, white
- Sun Exposure: Full sun to part shade
- Soil Needs: Average, medium moisture, well-drained
- Mature height: 2-5 ft.
- Blossoming period: Late spring
07 of 20
Amaranth

The Spruce / K. Dave

Several species within the Amaranthus genus are commonly known as amaranth or love lies bleeding. An excellent tall flower species is A. caudatus, which can grow to 3 to 5 feet with long panicles of dangling blooms. Another tall species is A. hypochondriacus, which grows to around 4 feet with flowers held in upright panicles in shades of red, purple, gold, and green. All the amaranths are easy to grow from seed. However, they are susceptible to many common garden pests.
- Name: Amaranth (Amaranthus spp.)
- USDA Growing Zones: 2 to 11 (annual)
- Color Variations: Red, pink, purple, yellow, orange, green
- Sun Exposure: Full sun to part shade
- Soil Needs: Average, moist, well-drained
- Mature height: 3-5 ft.
- Blossoming period: Summer, fall
08 of 20
Sneezeweed

The Spruce / Adrienne Legault

Sneezeweed (Helenium autumnale) is a clump-forming plant that grows to around 3 to 5 feet high with a spread of 2 to 3 feet. In the late summer, it blooms with daisy-like flowers that stretch roughly 2 inches across. They can persist until frost in the fall, bringing interest to the garden at a time when many other plants have finished blooming for the season. This plant does require some pruning maintenance, including deadheading to promote further blooming. Once flowering is done for the season, cut back your sneezeweed by half.
- Name: Sneezeweed (Helenium autumnale)
- USDA Growing Zones: 3 to 8
- Color Variations: Yellow
- Sun Exposure: Full sun
- Soil Needs: Average, medium moisture to wet
- Mature height: 3-5 ft.
- Blossoming period: Late summer, fall
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09 of 20
Spider Flower

The Spruce / Marie Iannotti

Spider flowers (Cleome hassleriana) start blooming early and get better as the season rolls along. The first blooms begin when the plants are only about 1 foot tall. As the plants grow, more flowers form at the top. Although height depends on the variety you are growing, most can reach 4 to 5 feet, branching along the way and producing even more flowers. You can direct sow seeds, and the plants easily self-seed in the garden. However, that means if you don't want them to spread you'll have to keep pulling seedlings as they pop up.
- Name: Spider flower (Cleome hassleriana)
- USDA Growing Zones: 10 to 11
- Color Variations: White, pink, lavender
- Sun Exposure: Full sun to part shade
- Soil Needs: Slightly acidic, medium moisture, well-drained
- Mature height: 4-5 ft.
- Blossoming period: Summer
10 of 20
Flowering Tobacco

The Spruce / Autumn Wood

Flowering tobacco (Nicotiana sylvestris) is a stately tall flower with clusters of trumpet-shaped blooms. It can grow to around 5 feet and produces a jasmine-like scent in the evenings. During the day, the flowers partially close, and no scent is released. Because of this habit, these are great plants for a patio or deck where you spend time in the evening. However, they should not be grown near tomatoes or other members of the nightshade family, as they all are susceptible to some of the same plant viruses. Flowering tobacco is toxic to humans and animals.
- Name: Flowering tobacco (Nicotiana sylvestris)
- USDA Growing Zones: 10 to 11
- Color Variations: White, yellow-green, pink, red
- Sun Exposure: Full sun to part shade
- Soil Needs: Rich, moist, well-drained
- Mature height: 5 ft.
- Blossoming period: Early summer, early fall
11 of 20
Mexican Sunflower

The Spruce / Marie Iannotti

Mexican sunflowers (Tithonia rotundifolia) are easy to grow and virtually pest-free. The species typically grows to around 4 to 6 feet tall, though dwarf cultivars are also available. These tall flowers love hot days and do equally well in high humidity or drought conditions. However, they can take a while to start blooming. To speed things along, start seeds indoors six to eight weeks before your area's last projected frost date in the spring.
- Name: Mexican sunflower (Tithonia rotundifolia)
- USDA Growing Zones: 2 to 11 (annual)
- Color Variations: Orange-red with yellow center
- Sun Exposure: Full sun
- Soil Needs: Average, dry to medium moisture, well-drained
- Mature height: 4-6 ft.
- Blossoming period: Midsummer, fall
12 of 20
Cosmos

The Spruce / Leticia Almeida

Cosmos (Cosmos sulphureus, Cosmos bipinnatus) is one of the most undemanding tall flowers you can grow. There are two common species of cosmos. C. bipinnatus has feathery foliage and daisy-like flowers with yellow centers, and some varieties reach up to 4 feet tall. C. sulphureus is a taller plant, growing to around 6 feet with yellow or orange flowers. Cosmos will repeat flower from summer to fall even without deadheading. However, the plants will last longer if you either deadhead or wait until flowering declines and shear back the whole plant by about half.
- Name: Cosmos (Cosmos sulphureus, Cosmos bipinnatus)
- USDA Growing Zones: 2 to 11 (annual)
- Color Variations: White, pink, red, yellow, orange
- Sun Exposure: Full sun
- Soil Needs: Medium moisture, well-drained
- Mature height: 4-6 ft.
- Blossoming period: Summer, fall
Continue to 13 of 20 below
13 of 20
Elecampane

The Spruce / Evgeniya Vlasova

Elecampane (Inula helenium) is a flowering perennial that’s part of the aster family. Its blooms have a sunflower-like appearance but with very thin, fringelike petals. The flowers stretch around 2 to 3 inches across and appear from midsummer to early fall. The plant overall can reach around 3 to 6 feet high. It’s tolerant of a variety of soil conditions. But it might need staking if it gets too tall. This plant is mildly toxic to humans.
- Name: Elecampane (Inula helenium)
- USDA Growing Zones: 3 to 7
- Color Variations: Yellow
- Sun Exposure: Full sun to part shade
- Soil Needs: Moist, well-drained
- Mature height: 3-6 ft.
- Blossoming period: Midsummer, early fall
14 of 20
Hardy Hibiscus

The Spruce / Leticia Almeida

Hardy hibiscus (Hibiscus moscheutos), also known as swamp mallow, is a shrub-like perennial that’s native to wet soils, such as river banks. In the summertime, it blooms with showy flowers that have five overlapping petals. And it grows to around 3 to 7 feet high with a 2- to 4-foot spread. This plant tolerates heat and humidity quite well and can be used in a rain garden. It’s important never to let its soil dry out and to protect it from strong winds.
- Name: Hardy hibiscus (Hibiscus moscheutos)
- USDA Growing Zones: 5 to 9
- Color Variations: White, pink
- Sun Exposure: Full sun
- Soil Needs: Rich, moist
- Mature height: 3-7 ft.
- Blossoming period: Summer
15 of 20
Kiss-Me-Over-the-Garden Gate

The Spruce / Evgeniya Vlasova

Persicaria orientalis, commonly known as kiss-me-over-the-garden gate or knotweed, is a quick-growing annual with spikes of purple-pink flowers that bloom from summer to fall above the foliage. The plant reaches around 4 to 7 feet high with a 2- to 4-foot spread. It will attract hummingbirds and other pollinators to your garden. But strong winds can damage it, so it must be in a protected site. Mulching is recommended to retain soil moisture.
- Name: Kiss-me-over-the-garden gate (Persicaria orientalis)
- USDA Growing Zones: 2 to 11 (annual)
- Color Variations: Purple-pink
- Sun Exposure: Full sun to part shade
- Soil Needs: Medium moisture, well-drained
- Mature height: 4-7 ft.
- Blossoming period: Summer, fall
16 of 20
Joe Pye Weed

The Spruce / Adrienne Legault

The tall flowers of Joe Pye weed (Eutrochium purpureum) arrive in the summertime and persist through early fall. The tiny blooms come in attractive clusters and have a pleasant vanilla scent. They’re known for attracting butterflies to the garden. This plant can reach around 5 to 7 feet tall and is easy to care for. Just make sure the soil doesn't dry out, or the leaves can scorch. Joe Pye weed looks best if you have the space to group several plants for more ornamental impact.
- Name: Joe Pye weed (Eutrochium purpureum)
- USDA Growing Zones: 4 to 9
- Color Variations: Pink
- Sun Exposure: Full sun to part shade
- Soil Needs: Rich, moist
- Mature height: 5-7 ft.
- Blossoming period: Summer, fall
Continue to 17 of 20 below
17 of 20
Canna

The Spruce / Adrienne Legault

The Canna genus includes tropical and subtropical plants with showy flowers. On average, they grow between 1 1/2 and 8 feet tall, though the exact height depends on the variety. The flower spikes rise above the foliage during the summer. These plants add rich, warm colors to the garden. But they have poor cold tolerance and must be brought indoors if the temperature nears 40 degrees Fahrenheit.
- Name: Canna (Canna spp.)
- USDA Growing Zones: 7 to 10
- Color Variations: Red, orange, yellow, pink, white, bicolor
- Sun Exposure: Full sun
- Soil Needs: Rich, moist, well-drained
- Mature height: 1 1/2-8 ft.
- Blossoming period: Summer
18 of 20
Delphinium

The Spruce / Autumn Wood

Delphinium, also known as larkspur, is a large genus of flowering plants that come in varying sizes. The Pacific Hybrid group includes tall flowers that grow to around 4 to 8 feet high. The flowers bloom in the summer clustered together on columnar flower spikes. While these plants offer lots of visual interest in the garden, they are fairly high-maintenance. They usually need staking to keep them upright, along with deadheading and pruning of spent growth. Delphinium is toxic to humans and animals.
- Name: Delphinium (Delphinium spp.)
- USDA Growing Zones: 3 to 7
- Color Variations: Blue, violet, pink, white
- Sun Exposure: Full sun
- Soil Needs: Rich, medium moisture, well-drained
- Mature height: 4-8 ft.
- Blossoming period: Summer
19 of 20
Sunflower

The Spruce / Ana Cadena

Annual sunflowers (Helianthus annuus) bloom in the summertime with their broad flowers on upright stalks. Gardeners have several options when it comes to these annuals. The traditional yellow sunflowers are still popular, but now you can also find cultivars in rich burgundy, deep mahogany, and many bicolors. They grow between roughly 3 and 10 feet high. And they don't require much care, though you can remove depreciated foliage for a tidier appearance. Birds love to feed on the seed heads. However, note that this plant self-seeds so readily that it is considered a noxious weed in some areas.
- Name: Sunflower (Helianthus annuus)
- USDA Growing Zones: 2 to 11 (annual)
- Color Variations: Yellow, red, brown
- Sun Exposure: Full sun
- Soil Needs: Average, moist, well-drained
- Mature height: 3-10 ft.
- Blossoming period: Summer
20 of 20
Castor Bean

The Spruce / Evgeniya Vlasova

Castor bean (Ricinus communis) plants are tall flowers that can reach around 6 to 10 feet high with a 2- to 4-foot spread. They grow quickly with glossy green foliage. In the summer and fall they bloom with somewhat insignificant flower spikes. It’s the reddish-brown seed capsules that have the real ornamental value. Situate it somewhere that's protected from strong winds. While this plant provides lots of visual interest to the garden, all parts of it are toxic to people and animals. So be sure to plant it away from areas with children and pets.
- Name: Castor bean (Ricinus communis)
- USDA Growing Zones: 9 to 11
- Color Variations: Green-yellow, red
- Sun Exposure: Full sun
- Soil Needs: Rich, moist, well-drained
- Mature height: 6-10 ft.
- Blossoming period: Summer, fall

Learn More

Now that you know about the tall types of flowers that can anchor your garden, read more about plants that add even more flair to your yard. Learn about plants that produce the biggest, most vibrant, fragrant, and dramatic blooms.

14 Easiest Flowers to Grow From Seed

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