If you’ve been seeking flowers that will bloom all season, you’ve come to the right place. We’ve compiled a list of the top annuals and perennials that produce flowers from spring until fall frost. Each has been selected to provide colorful blooms throughout most of the season.
Understanding Bloom Cycles
Although the annuals and perennials on this list will bloom through all or most of the summer, they won’t necessarily be blooming at all times.
This is because flowering perennials, as well as shrubs, usually have what is called a bloom cycle. This is a period of time during which the plant sets buds, develops them, produces flowers, drops them, and then begins that process all over again.
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So, while you may notice that some of your perennials look like they’ve stopped flowering, all they’ve really done is dropped their last batch and started on the next one.
The exception to this rule is the hardy hibiscus, which has a nigh-continual supply of buds whose flowers last only one day.
Top Ten Annual Flowers
- Fan Flower — Scaevola
The petals of these flowers are arranged all along one side, making each one look like a lady’s fan. They come in many shades of blue as well as in white and sometimes pink, and they bloom from late spring until the first frost.
This plant has a spreading growth habit and is one of the best annuals for pots or hanging baskets, but it also makes a great ground cover.
These flowers are brightly colored and interestingly-shaped, and hang like water droplets from their stems, making them ideal for hanging baskets. Hummingbirds quite like them too!
Despite their name, fuschias come in a range of other colors. The cap-like sepals, or top parts of the flower, can be white, red, or pink, while the interior corolla can be blue-violet, white, purple, pink, or orange-pink.
Fuschias do best with a little extra moisture and a little more organic matter in their soil than your other garden plants. In very hot and sunny places, give your fuschias some afternoon shade.
Petunias have been garden standbys for decades, but the wealth of colors and number of blooms they provide throughout the season means that they won’t be going out of style anytime soon. ‘Supertunia’ hybrids are especially productive.
These trumpet-shaped flowers grow on bushy or spreading plants and bloom well throughout the season–except in places with very high humidity, where their color is best in spring and fall.
- Spider Flower — Cleome
Tall, branching, and topped with unique, fluffy, spider-shaped flowers in summer and fall. Cleome is a wonderful cut flower, and is also striking when grown against fences, at the back of flowerbeds, or as part of a tall border. We think it’s a good swap for the more prosaic but also-tall sunflower. Spider flowers generally come in shades of pink, white, or red.
It likes heat and can reach up to 6 feet tall in the best conditions, although it’s more likely to top out around 4 feet. It is easily grown from seed once the soil warms and tends to self-sow.
- Moss Rose — Portulaca
This low-growing plant looks almost like a succulent thanks to its smooth, fleshy leaves. Like succulents, it prefers dry soil and hot conditions, so it’s a great flowering annual for those spots in the garden that get baked by the sun.
The roselike flowers of this plant that give it its common name bloom on the end of each trailing stem from spring to frost. Each flower is up to 1 inch across in red, rose pink, orange, yellow, cerise, or white, with single-color or mixed-color varieties available.
This Australian native will provide bright color in every month of the year in mild climates, and from spring till the first hard frost in most others. It also grows quickly, giving almost instant gratification to the impatient gardener. It likes very bright sunlight and could develop mildew if planted in too much shade.
Lantana is available in spreading and in shrubby forms, with each featuring coarse, dark-green leaves that are rabbit and deer resistant thanks to their texture and pungent odor when crushed. The flowers consist of small blooms gathered in large clusters that are 1-1.5 inches across, in red, orange, yellow, magenta, or combinations thereof.
Be aware, however, that certain species of lantana can be invasive.
These daisy-like flowers are actually part of the sunflower family and is native to tropical South America. Like sunflowers they are easy to grow even in somewhat poor soils, colorful, and tend to get tall (from 3-6 feet). But unlike sunflowers, they have soft, feathery foliage and tend to be as bushy as they are tall.
Cosmos flowers are found in many forms–single, double, rolled, quilled, or crested–and in many colors from white to crimson to orange. They are great for mass color in the garden, for cutting gardens, and for making pressed flowers, and bloom from early summer until frost.
The sand-dollar-shaped leaves of this annual are as unusual as the shape of its five-petaled flower. Nasturtiums are easy to grow in sandy, warm soils, and they bloom well throughout the heat of summer up until the frosts of fall. They are widely available in mixed or separate colors, ranging from orange to red, maroon, burgundy, and creamy white.
As a bonus, they are also edible, with a peppery flavor that is great in salads.
This tropical plant is a fast-growing annual in most of North America. Mandevilla generates thin, twining stems sporting attractive, glossy foliage. Its tubular flowers are attractive to hummingbirds and butterflies and can be pnk, red, or white.
In hot climates, they will benefit from afternoon shade. Some gardeners grow Mandevilla as a groundcover or in a hanging pot, while others provide support in the form of a trellis or stake.
- Garden Sage — Salvia
While culinary sage is grown for its aromatic, flavorful foliage, its cousin salvia or garden sage is cultivated for its tall flower spikes that bloom from early summer to frost. Each spike has a collection of two-lipped flowers that are either spaced out along the stalk or clustered tightly together.
There are perennial varieties of salvia, but these usually only come in purple or blue-violet; annual garden sage boasts colors that range from indigo to scarlet to red-pink to purple. The plant itself is sturdy, deer and rabbit resistant, and can be anywhere from 1 to 3 feet tall. Some types are also aromatic, others less so.
Top Ten Flowering Perennials
Don’t want to have to buy and plant new flowers every year? Luckily, there are plenty of low-maintenance perennials to add color and beauty to your garden with less effort. Unlike annuals that only survive for a season, you can count on perennials to survive the cold of winter and come up strong in the spring.
Here are the top ten flowering perennials that bloom all year, from spring until fall:
This perennial has a bushy lower area, with pink four-petaled flowers that bloom far above the body of the plant on tall, wavy stalks. The flowers of a gaura are pink, white, or fuschia, and the foliage can be green or dark burgundy.
Gaura is a large perennial that can get up to three feet tall and wide. It works great in planters and borders, or as an accent to large-leafed shrubs and trees due to its airy appearance.
- Monch Aster
The Monch is the longest-blooming type of aster. Other varieties typically only begin blooming in late August to September, while the Monch gets going in early to mid-July. It has slightly hairy leaves and reaches about 3 feet tall. It bears an abundance of lavender-blue, 2-inch-wide flowers outfitted with fine, square-edged petals.
- Blanket Flower – Gaillardia
Gallardia loves heat and does well in sandy soils. It’s daisy like flowers come in eye-catching shades of red, orange, maroon, or yellow, and begin blooming in early summer and last until the first frost. This makes it one of the longest-blooming perennials even on this very list.
Galliardia is also easy to start from seeds, and tends to reseed itself as well. It’s a great bright spot in the garden and also makes a great cut flower for bouquets, either the blooms themselves or the round gray seedheads.
Varieties like ‘Burgundy’, ‘ Torchlight’, and ‘Tokajer’ grow to 2.5 feet tall and wide, while dwarf varieties like ‘Baby Cole’ and ‘Goblin’ grow to 1 foot tall and wide.
- Hummingbird Mint – Agastache
Also known as giant hyssop or anise hyssop, this member of the mint family has aromatic leaves and tall flower clusters that draw moths, butterflies, and, of course, hummingbirds.
Most types average two feet wide by two feet tall, although it can grow larger in mild climates. The flower spikes themselves are anywhere from six to twelve inches long, with a range of colors available from pink to yellow to apricot–all with a unique frosty undertone.
This perennial is deer and rabbit resistant thanks to the oils in the leaves that provide it with its distinct licorice- or anise-like fragrance.
- Beardtongue – Penstemon
This flower is native to the Western US and does best in very fast-draining soils. The bright, tubular flowers rise on long stalks above glossy green foliage and bloom from early summer to early fall.
Bright blue and red are the most commonly found colors of penstemon, but new hybrids and cultivars are bringing colors like bright pink, deep purple, coral, and lemon yellow to the garden.
As a bonus, this is another perennial that hummingbirds are drawn to thanks to its bright colors and tubular flower shape.
- Carnations – Dianthus
On oldie but a goodie, dianthus have been well-loved by gardeners for their gray-green foliage, profuse 2-inch-wide flowers, and their unique, spicy, clove-like scent.
Some dianthus are low and bushy and grow to 12 inches wide and tall, making them great for borders. Others are developed for cut flowers and can grow up to 2 feet tall–excellent for cutting gardens.
The fragrant flowers of dianthus come in shades of pink, red, or white, and often have striking patterns or fringed edges as well.
- Balloon Flower – Platycodon
This whimsical flower is named for its four-petaled, unopened buds that look like inflated balloons at the ends of long, upright stems. These buds open in 2-inch-wide, blue-violet star-shaped flowers in early summer, and continue to bloom into fall.
Balloon flowers can also be found in pink and white varieties. Unlike other more vigorous perennials on this list, Platycodon takes two to three seasons to establish a strong root system, so avoid disturbing it after you’ve planted it. It also likes afternoon shade in hot climates.
- Tickseed – Coreopsis
This member of the sunflower family pushes out wave upon wave of flowers over the season in cheerful shades of orange, maroon, reddish, and yellow. Coreopsis tends to grow tall, usually reaching at least 2 feet in a season, with the flowers held above the foliage on long stems.
This low-maintenance perennial likes full sun, tolerates poor soils, naturalizes easily to fill spaces, and is reasonably drought-resistant. It also responds very well to an occasional shearing to trigger new blooms–more on that below!
- Speedwell – Veronica
Another old-fashioned favorite, speedwell features spike-shaped plumes of flowers on sturdy stalks above glossy green foliage. Each 4-6 inch flower spike consists of a mass of tiny flowers ¼-½ inch wide, so that what looks like one big flower from far away crystallizes into a cluster of close-up detail.
Low-growing, groundcover veronica types include V. alpina ‘Alba’, V. repens, and V. ‘Waterperry,” which form dense foliage mat enlivened by their flowering spikes. The tallest and more common variety is V. spicata, which grows up to 2 feet tall.
- Rose Mallow – Hardy Hibiscus
There are many types of hibiscus, but the hardiest one is Hibiscus moscheutos, or rose mallow. It’s hardy down to Zone 5 and will survive winter temps down to -20 degrees Fahrenheit. That means that this perennial can bring a touch of the tropics as far north as Colorado!
It also has the biggest flowers of all the hibiscus species, up to 1 foot across, that can be red, pink, or white. White flowers can also have a red “eye”. The plant itself can grow to be 6-8 feet tall, with large toothed leaves that give it dense bushiness.
How to Encourage Flowering
Though each of these beautiful perennials and cheerful annuals will flower well on their own, there are a few things that you can do to help them be even better!
Fertilize with bloom boosters. Use a fertilizer that has extra phosphorus, like this OMRI-certified one from Down to Earth (link to Amazon). This is the middle number of the three that you’ll find on the front of fertilizer packages, and it encourages the production of buds and the blooming of healthy flowers.
Plan to fertilize every four to six weeks, according to the directions on your fertilizer. For perennials it’s also helpful to fertilize one last time in mid-fall, which provides the plants a little extra nutrition going into winter, and also makes it easily available to them first thing in spring when they start to wake up from winter dormancy.
Protect from the wind. This isn’t always possible, but flowers do tend to stick around longer when they’re not being beaten up by the breeze. This is especially true of the larger flowers like hibiscus and balloon flowers. Behind a fence, beside a wall, or in a planter close to your house are all more sheltered spots in the typical yard.
Deadhead or cut back. This is the practice of removing spent blooms in order to get more new flowers out of the plant. The biological drive behind producing flowers is to set seed, so removing a flower, even a dead one, automatically prompts the plant to generate more buds to blossom.
You can deadhead individual flowers off every perennial on this list, but for coreopsis, gaura, and dianthus, they produce so many small flowers at once that it’s usually easier to cut them all back together. Simply wait until the flowers on the plant have mostly all faded, then use shears to cut back the stems in one fell swoop. This will trigger another wave of flowers from the base of the plant.
How To Propagate Perennials By Division
Are you really loving your penstemon and want more of them in your garden? All you need is a healthy mother plant and a shovel to propagate more of them!
Perennials tend to form dense clumps of roots over time, and dividing them every so often will actually help keep the plants strong and healthy.
For perennials on this list, which bloom from summer into fall, early spring is actually the best time to divide. At this time the roots are still full of stored energy and are just beginning to send out leaves, which are less easily damaged than full-grown leaves. Plus, dividing and replanting in the spring instead of the summer or fall will give them the whole season to recover, instead of just a few weeks before frost.
Additionally, spring tends to be cooler and wetter than other seasons. The cool temperature will prevent the roots from drying out or experiencing stress from the heat during the division process, and the extra moisture will help the divided sections re-establish their individual root systems.
How To Divide Perennials
- Water the area well the day before you plan to divide, and carry out the project on a day that is cool and, ideally, overcast, as opposed to one that is sunny and warm.
- Use a shovel or garden fork to lift the root ball of the mother plant up out of the ground.
- Separate the root ball by gently pulling it apart with your hands, but cutting it with a knife, or slicing it with the edge of the shovel.
- Re-plant each divided piece in prepared ground. Make sure to water daily for the first week until the worst of the transplant shock has passed, then resume regular watering.
How to Save Seed From Annual Flowers
If you’d like to save seeds from your favorite annuals to replant or even to share them, you can! Cosmos, petunias, cleomes, and nasturtiums are among the easiest flowers to save seed from, but you can try it with any of them.
Keep in mind that the flowers grown from seed that you save may not be exact replicas of the original flowers. Hybrids like the Supertunia, which comes from two-parent petunias cross-pollinated by a plant breeder, will just revert back into one of the parent plants. Meanwhile, cross-pollination of flowers can happen in your garden of its own accord, creating unintentional hybrid seed.
How to Save Flower Seed
- Choose your flowers for saving seed–the largest, prettiest, and brightest plants you have.
- When the flowers on the plant begin to go brown and lose their petals, allow the flower to dry down completely. This may take up to a month from when the flower first begins to fade; however, don’t wait too long, in case the flower releases its seed before you can get it.
- Collect the dried flowers. If they aren’t totally dry or you aren’t ready to work with them, place them in a labeled paper bag (not plastic!).
- To harvest seed from the flowers, gently crumble the flowers between your hands into a bowl or even a casserole dish. Sift through the chaff and remove the seeds.
- Place the harvested seeds in an envelope that is clearly labeled with the name of the flower and the date you harvested. You might even want to make notes about their color or growing habits, to see if future generations live up to their promise!
- Store these seeds in a cool, dry, dark location. If you live in a humid area, put them inside an airtight container to prevent mold or rotting.
These durable flowering perennials and long-lasting annual flowers will provide color and beauty to your garden year after year. With regular fertilizer and just a bit of deadheading, they will produce their brightest blooms all season long, from the first stirrings of spring until the cold frosts of fall.