Choosing perennials for your garden
The best way to have success when growing perennials is to choose the right plant for the specific location. Consider the type of soil, how much moisture it retains, how much sun or shade the area gets, and how exposed it is to the wind. There is a perennial plant for every situation, so matching their preferences to your site will ensure they grow for many years. Choose a variety that flowers at different times of the year and combine with shrubs, ornamental grasses, and annuals for a long lasting display.
We’ve compiled a list of the 20 best perennials to grow, as well as tips on how to purchase and cultivate them.
BEST PERENNIALS FOR FULL SUN
AGASTACHE (Agastache spp.)
This plant grows best in zones 3-10. It blooms in the summer and fall. It has an upright spreading habit and grows 1 to 6 feet tall and 1 to 3 feet wide.
This mint relative is known for its pleasingly aromatic foliage. It has long-lasting spiky or tubular flowers in an array of colors and shapes that are especially attractive to hummingbirds, butterflies, and other insect pollinators. This North American native is exceptionally drought tolerant, deer- and rabbit-resistant.
BEE BALM (Monarda spp.)
An herbaceous plant that blooms from late spring until early fall, the Moneywort has an upright, spreading habit. It typically reaches 10 inches to 4 feet in height and 8 inches to 3 feet in width.
Bee balm is a plant that is related to mint. Its leaves have a strong scent that is similar to sage. The plant has clusters of tubular flowers that can be lavender, pink, purple, red, or white. It is native to North America and the flowers attract hummingbirds, butterflies, and other insects that help with pollination.
BELLFLOWER (Campanula spp.)
This plant can grow to be anywhere from 4 to 48 inches tall, and 6 to 48 inches wide. It has a blooming period from late spring to fall, and can have an upright, mounding, or creeping habit.
Bellflower is a flower that is often found in cottage-style gardens. The flowers are white, pink, purple, or blue, and are cup- or bell-shaped. The foliage is serrated, heart-shaped, or pointed, and is green or gold. There are three different forms of bellflower, which are stately upright types, mounding varieties, and creeping groundcovers.
BLACK-EYED SUSAN (Rudbeckia spp.)
This plant grows best in zones 3-9, depending on the specific variety. It blooms in the summer and fall, and has an upright spreading habit. This plant typically grows 1-9 feet tall and 1-5 feet wide.
This plant lives for two years or less, and is originally from North America. Its flowers, which look like daisies and can be gold, bronze, red, orange, brown, or yellow, provide bees and butterflies with nectar. The plant’s seedheads give songbirds food to eat during fall and winter.
BLAZING STAR (Liatris spp.)
This plant does well in zones 3-9 and blooms in summer to fall. It has an upright habit and is 1 to 5 feet tall and 6 inches to 2 feet wide.
This flower, which is native to North America, is also known as the gayfeather. This is because the feathery flower plumes look like bottle brushes. The purple or white spiky flowers that bloom throughout the summer are very attractive to bees, butterflies, and other insect pollinators. The blazing star is tolerant of drought and poor soils, but it is essential that the soil has good drainage.
CANNA (Canna spp.)
This plant does best in zones 7-11 and will bloom in mid-summer to fall. It has an upright spreading habit and can grow 1-1/2 to 8 feet tall and 1-1/2 to 6 feet wide.
Plants typically grow 3 to 6 feet (91 to 183 cm) tall with an equal spread. This tropical plant is related to bananas and flowering ginger. It is grown for its bold foliage which can be found in different colors and patterns. The flowers of the plant are red, orange, yellow, or white. It thrives in warm weather and can be grown in containers or mixed borders. The plant is typically 3 to 6 feet tall.
CATMINT (Nepeta spp.)
Zones 3 through 9 bloom from late spring to fall. This plant has a mounding spreading habit and grows 1 to 4 feet tall and 1 to 3 feet wide.
This hardy, long-lived plant has small tubular flowers in various colors blooming along its stem from late spring to early fall. This provides a consistent nectar source for hummingbirds, bees, and other insect pollinators. The mint relative is easy to care for and tolerant of different growing conditions.
CONEFLOWER (Echinacea spp.)
This plant blooms in summer and has an upright spreading habit. It typically grows 1 to 5 feet tall and 1 to 2 feet wide.
This North American prairie native is extremely important for insect pollinators, as its nectar provides them with food. Additionally, its seedheads provide food for songbirds through fall and winter. In recent years, there have been some major breeding breakthroughs that have resulted in a wider range of flower colors and plant sizes. For example, the cone-shaped blooms now come in pink, white, yellow, green, red, and sunset hues.
DAYLIY (Hemerocallis spp.)
This plant grows best in zones 3-9. It blooms in late spring to fall, and has an upright spreading habit. It grows 1 to 6 feet tall, and 1 to 4 feet wide.
Daylilies are flowering plants that have lily-like blooms. The blooms only last for one day, but there are many of them, so the plant looks nice for several weeks. Daylilies come in many colors, including yellow, orange, and red. They grow best in a place that gets a lot of sunlight and has soil that drains well.
RUSSIAN SAGE (Perovskia atriplicifolia)
This plant does best in zones 4-9. It blooms in early summer and continues into fall. It has an upright, spreading habit and grows 2-4 feet tall and wide.
This herb is perfect for anyone who wants a low-maintenance garden that will still be beautiful and lively. Russian sage is known for its aromatic gray-green foliage and its tubular lavender-blue or purple flowers that bloom for weeks. Not only is it a reliable workhorse, but it also attracts hummingbirds, butterflies, and other insect pollinators. Plus, it’s drought tolerant, disease resistant, and deer resistant.
SHASTA DAISY (Leucanthemum x superbum)
This plant grows best in zones 5-9. It blooms in early summer and continues through fall. It has an upright spreading habit, and grows 6 to 48 inches tall and 12 to 36 inches wide.
This perennial blooms in the summer and has white petals with a yellow center. There are many cultivars that have either single or double petals in a range of flower and plant sizes. The blooms attract butterflies and other insect pollinators. These plants can tolerate drought and different soils, but they need good drainage to thrive.
SPEEDWELL (Veronica spp.)
The plant grows best in zones 3-9, blooming from late spring to fall. It has an upright or creeping habit and can reach a height of 3 to 48 inches and a width of 8 to 24 inches.
Speedwell is a long-blooming perennial that is easy to take care of once it is established. The most common varieties have an upright habit with elegant blue, purple, pink, or white flower spikes. The forms that creep produce dainty blue or white flowers that look like forget-me-nots.
SEDUM / STONECROP (Sedum spp.)
This plant does well in zones 3-9 and blooms in the summer and fall. It has an upright, mounding, or creeping habit and is 3 to 36 inches tall and 12 to 24 inches wide.
This perennial is popular because it is easy to grow and does well in a range of conditions. It has brightly colored leaves and flowers that attract butterflies and other insects.
When to plant perennials
Now is the ideal time to plant hardy perennials because the soil is still warm and the plants can develop a good root system before next spring.
Perennials should be watered during dry spells and hot temperatures in summer. The best time to plant perennials is in spring or autumn. Planting in spring gives the plants ample time to establish before winter.
It is possible to plant perennials during the summer, but it is important to make sure that the plants are watered regularly for the rest of the growing season as there is typically less moisture in the soil during this time.
In areas with mild winters, you can plant hardy perennials, as long as the ground isn’t frozen or waterlogged.
How to plant perennials
Before planting perennials, it is important to till the ground and remove any large stones or weeds that could impede growth. Adding organic matter to the soil can also improve growth.
Make a hole in the ground that is a little bigger than the roots or pot of the plant. Take the plant out of the pot and loosen any roots that have wrapped around the rootball. Place the perennial plant in the ground so that the top of the rootball is even with the soil surface. Refill the hole with soil and press down lightly to remove any air pockets. Water the plant thoroughly.
Caring for perennials
- In early spring, feed your perennials with a general slow-release fertiliser and mulch the bare soil between plants with well-rotted organic matter
- In spring or early summer, support tall-growing perennials with stakes such as canes and string, or grow-through plant supports placed over the clump
- Through spring and summer, keep the surrounding ground clear of weeds
- Remove dead and faded flowers to prolong the flowering season and to keep plants looking good
- In autumn, cut back fleshy-leaved perennials as soon as they die back, otherwise the leaves go soggy and rot
- Woody-stemmed perennial growth can be left until late winter/spring before cutting back. Frost, mist, and snow transform parchment-coloured stems into a winter wonderland, and during very cold winters, this growth also helps protect the roots from damage by severe frosts. Beneficial insects such as ladybirds hibernate in dead stems
- Tidy evergreen perennials from time to time to remove dead or tatty leaves and faded flower stems
- After three to five years, perennials tend to form large clumps and performance starts to decline. Lifting, dividing and replanting them will rejuvenate plants and provide you with more plants to grow around the garden
How to propagate perennials
Perennials are great value for the thrifty gardener. Many can be started cheaply from seed, then, once they have formed sizeable clumps, most can be multiplied by division, breaking up the clump into sizeable pieces to replant while getting rid of the old, woody centre.
Advice on buying perennials
- Perennials are widely available at nurseries and garden centres, usually in at least two different pot sizes so you have the option of buying more costly plants for instant impact, or smaller ones that take a year or two to grow
- Perennials can also be bought by mail order – the best time to buy is autumn to spring, when plant growth is dormant, and they are more easily transported. Bare rooted plants are available whilst dormant, which avoids using plastic pots and is often cheaper
- Perennials can also be bought as plug plants, which are small and need growing on in pots before planting in the garden.