Carefree Perennials

persicaria polymorpha

Looking like an Astilbe on steroids, Persicaria polymorpha blooms for a long time in early summer. Deadhead to keep the plant looking neat, but otherwise just stand back and enjoy.

Throughout the growing season a steady stream of customers enter the garden center saying, “I’m tired of planting annuals every year… I need plants that aren’t any work. Where are the perennials?”

As I show them the way toward the perennial section, I explain to these customers that all perennials are not carefree. Some perennials are easy and reliable, but if you choose the wrong plants, a perennial garden can be the most high-maintenance garden you can plant. A low-maintenance garden starts with the location, choosing the right plants, and treating them appropriately once they are placed in the garden.

Location and Cultural Conditions
Before I make any perennial plant recommendations, I always ask my clients how much sun their garden receives, and what the soil is like. Any plant that is trying to grow in sub-optimal conditions is likely to be more work. Sun loving plants that grow in the shade, for example, are apt to grow tall and spindly as they reach for the sun. A plant that requires good drainage is apt to rot or become diseased when planted in consistently damp soils, so it will need replacing or treatment with fungicides.

If a perennial receives the wrong care after planting it can lead to problems that mean work for the gardener. Over-fertilization leads to perennial plants that are larger, weaker and more prone to insect and disease attack. Many plants also become feeble from too frequent watering, or their foliage develops leaf spot from being hit with automatic sprinkler systems. So even the most low-maintenance plant will require more work if it is not given the best environment.

The garden’s location can also turn a good plant into a problem child. Some perennials are carefree in one part of the country but are prone to problems in another climate or different type of soil.

It Has to Live
Given the proper location and care, what makes a perennial carefree? To my mind, the first thing we look for in a plant is one that will, baring the unexpected, dependably live for five years or more. Let’s be honest: some perennials return reliably year after year, but there are others that if you get them back for more than one season it’s a gift from God.

russian sage

One of the longest blooming perennials for sun, Perovskia atriplicifolia is covered with lavender flowers from July until hard frost. Plant Russian sage in full sun and very well drained soil.

No Frequent Dividing
In addition to longevity, a carefree perennial should not need frequent editing or dividing. There are many fine perennial plants that are determined to take over the world, starting with your garden. Such plants are usually fine for the first two years after planting, but in the third season it becomes clear that once established, the plant more than doubles it’s size from season to season.

Perennials that spread quickly need to be divided every other year in order to keep them from dominating the garden. Such digging and dividing may also be required to keep the plant blooming well and looking it’s best. Siberian iris, for example, may stop blooming when they have been in place for several years. Perennials such as Shasta daisies grow into an unattractive donut shape as they age, so they must be dug up and divided every other year to keep the clumps full and appealing. In contrast, low-maintenance perennials usually spread slowly and don’t require dividing.

Does Not Self-Seed Prolifically
Although most gardeners enjoy finding some self-seeded perennials in the garden, those that annually sow an abundance of seeds are make-work plants in the garden. Carefree perennials may self-seed occasionally, but they are not prolific self-seeders so you won’t have to spend hours weeding their offspring out of the garden.

Disease and Insect Resistant
Carefree perennials aren’t prone to insect or disease attack. A plant that requires spraying in order to keep it disease-free, or one that needs routinely needs applications of pesticides, doesn’t belong in a low-maintenance perennial garden.

To Stake or Not to Stake
In general, most carefree perennials should not require staking, although if a plant meets the criteria in every other way except this, it could still be considered a low-maintenance addition to the garden. Some plants, such as peonies, are usually problem-free but they happen to have heavy flowers. Other plants become leggy or weak because they are given too much water or fertilizer. Even the sturdiest of plants will need support when they are fed or watered too much, so a gardener looking for less work will keep their plants on a lean diet.

Deadheading May be Optional
Although most of my customers say that they’d like a perennial that blooms all summer, the reality is that most are in flower for two to six weeks. A long bloom period isn’t really essential for a beautiful garden, however. There are many carefree perennials that are very attractive before and after bloom, and one of the delightful things about a perennial garden is the change throughout the season. But in order to keep the garden looking it’s best some plants will need deadheading.

The Right Cultivar
Finally, some cultivars of perennials are carefree while their parent plants, or other hybrids of the same genus, are not. For instance, some perennial geraniums are reliable and low-maintenance, while others are prone to leaf diseases, look awful after flowering, or die quickly. As you read the list below remember that the plant I’ve mentioned may be low-maintenance, but another species or cultivar in the same genus may not.

This list is not all-inclusive and I may have omitted some of your favorites…limited space demands that I omit some of mine! And experienced gardeners might consider some of these plants “old hat”. Although I can’t list every carefree perennial I’d be negligent if I didn’t include at least some of the tried and true for they are widely planted and loved for a reason.

Athyrium felix-femina (lady fern – zone 4 – Part Shade/Shade)
A beautiful and robust native fern, A. felix-femina is a clump-grower that reaches two to three feet high and four feet wide so give it plenty of room. This plant does well in moist soils or a well-amended garden that is watered once a week during drought.

Baptisia australis (false indigo – zone 3 – sun/part sun)
Baptisia is valued for pea-shaped flowers in early summer and for bluish green foliage the rest of the season. Plants usually grow to four feet high and wide after three seasons in the garden. Deadhead after bloom to prevent the heavy seedpods from pulling the plant to the ground. Place your Baptisia well because this plant has a deep root system and does not like to be moved. Baptisias varieties are available in an assortment of colors and they are drought-tolerant, native plants.

Calamintha nepeta ssp. Nepetoides (lesser calamint – zone 5 – sun/part sun)
There is nothing “lesser” about this plant! It grows in a tidy clump that is only 18 inches high, yet it blooms in the late summer into fall. The tiny flowers are white early in its bloom period, but intensify to pale lavender-blue in the fall. Plant calamint in groups of three or five for the best effect.

Cimicifuga simplex ‘Brunette’ (purple-leaved bugbane – zone 4 – part shade)
One of the first of several dark-foliage Cimicifuga cultivars, ‘Brunette’ has proved to be classy, reliable and fragrant. The purple foliage stays low and attractive and the white bottlebrush-like flowers grow to 4 or 5 feet tall, coming into bloom in early fall. Although this perennial is happy in constantly moist soils, it does not demand a swamp: amend the soil and water deeply once a week.

Dicentra spectabilis (old-fashioned bleeding heart – zone 3 – part sun/shade)
This easy perennial is deservedly popular for the sweet rows of dangling heart flowers. About the worst thing you can say about D. spectabilis is that it frequently goes dormant in hot weather. When this happens cut the plant to the ground as soon as it starts to yellow and plant annuals around it. Dicentra spectabilis grows two to three feet tall and three feet wide.
Eupatorium rugosum ‘Chocolate’ (purple-leaved boneset – zone 3 – sun/part sun)
This variety of the native boneset has attractive purple-green foliage early in the season. The leaves turn green in September-October when the plant becomes a cloud of white flowers. The plant does not spread appreciably and requires no maintenance from early spring until hard frost. ‘Chocolate’ grows 3 to 5 feet tall depending on soil type, fertility and moisture.
Geranium macrorrhizum (zone 3 – sun/part shade) Without a common name that distinguishes it from the zillions of other cranesbills, G. macrorrhizum is a must-plant perennial if you like weed-smothering plants. It spreads quickly enough to be a ground cover, but slowly enough so that you’ll never curse its presence in your landscape. There are several named varieties with pale pink to fuchsia colored flowers, and all plants grow to about 15 inches high. One of the few plants that tolerate dry shade, G. macrorrhizum blooms in June and looks attractive after bloom.

Helenium ‘Sahin’s Early Flowerer’ (Helen’s flower – zone 3 – full sun)
Although this variety has an unfortunately long name, the plant itself is shorter than most so it will never need staking. The flowers come into bloom earlier than other Heleniums and continue producing yellow and orange flowers for a long time.

Hemerocallis species and hybrids (daylilies – zone 3 – sun/part sun) There is a daylily for every garden as there are hundreds of cultivars in all sizes and colors. Even the spreading, orange “ditch lilies” are carefree plants when planted where they can be a groundcover. Among the clump-growing hybrids the varieties that bloom late, such as ‘Final Touch,’ are less work in that they are attractive from spring until blossoming stops in mid-September. Early bloomers such as ‘Stella de Oro’ must be cleaned right after flowering because there is nothing more ugly than an un-deadheaded ‘Stella’.

Hibiscus hybrids (rose mallow – zone 4 – sun/part sun)
The herbaceous perennial form of Hibiscus has large, showy flowers in mid or late summer. There are short varieties that grow to about 3’ tall and cultivars such as ‘Raspberry Rose’ that reach 7 to 8 feet in a single summer. Most varieties are somewhere in the middle, and have flowers ranging from white to red and every shade of pink in between. A completely no-work plant…just be aware that they get wide and are very late to break dormancy in the spring.

Hosta hybrids (hosta – zone 4 – part sun to shade) All the books list “plantain lily” as the common name, but have you ever heard anyone use it? Hosta it is and Hosta it should be, and whether you want a low groundcover, a drift of fresh foliage, or a large specimen plant, there is a Hosta that will fill the bill. Beware of automatic sprinkler systems, however: if the foliage is frequently splashed with water it promotes unsightly leaf-spot fungus.

Kirengeshoma palmata (yellow waxbells – zone 5 – part sun or part shade)
Yellow waxbells is a large plant, and is best planted singly as a specimen. Large maple-like leaves appear in early summer followed in late summer by pale yellow bell-shaped flowers that continue to bloom over a six-week period. Like Baptesia, this plant does not transplant well so place it appropriately. Plant Kirengeshoma at least four feet from any other large plant or passageway….I learned the hard way and now I have to move a stone path in order to accommodate a plant that has matured to five feet tall and five feet wide.

Ligularia “The Rocket” (zone 5 – Part sun or part shade)
Another large, structural plant for shady gardens. The foliage gets to around three feet tall and the yellow spires rise a foot or more above the leaves in July. This plant is best when placed in morning sun and afternoon shade because even if the soil is damp this plant will wilt in hot afternoon sunlight. Ligularias grow well in moist soils making it the perfect plant for next to the downspout or that poorly drained area.

Nepeta faassenii ‘Six Hills Giant’ (catmint – zone 3 – sun or part sun)
‘Six Hills Giant’ is a lovely lavender-blooming plant that looks good no matter how you treat it. You can leave it as is all summer, cut the stems in half in early July to stimulate more growth and flowers, or cut it to the ground to make room for late-summer annuals. This Nepeta gets two to three feet tall and wide and is the perfect plant to combine with ornamental grasses.

Paeonia lactiflora hybrids (peony – zone 3 – sun)
New peonies take a few years to become established enough to bloom, but once they mature they require little care. If the foliage gets mildew or other leaf diseases in late summer simply cut the entire plant to the ground. If you’d rather not stake heavy blossoms just cut the flowers and enjoy their beauty and fragrance in a vase indoors.

Perovskia atriplicifolia (Russian sage – sun – warm zone 4)
One of the longest flowering perennials, Russian sage is drought tolerant and around four feet tall. This plant looks shrubby with silvery gray foliage and purple-blue flowers. Leave this woody perennial in the garden over the winter and prune down to one third in the spring.

Persicaria amplexicaule ‘Firetail’ and ‘Golden Arrow’ (zone 4 or 5 – sun/part sun)
‘Firetail’ and ‘Golden Arrow’ bloom from July until hard frost in sun or quite a bit of shade. These Persecaria grow to about four feet high and do best in well-amended soil. Both have bright reddish-pink flowers, and ‘Golden Arrow’ has yellow/lime foliage. Good flowers for cutting.

Persicaria polymorpha (zone 4 or 5 – sun/part shade)
White fleecy flowers on five-foot tall stems, this Persicaria looks like an Astilbe on steroids. It blooms from early through mid-summer, and never needs staking. Very reliable.

Platycodon grandiflorus hybrids (balloon flower – zone 3 – sun/part sun)
Balloon flower has deep roots and doesn’t transplant well, but they are delightful mid-summer bloomers. The tall varieties can be sheared to stimulate shorter, bushy growth, but shorter cultivars such as ‘Early Sentimental Blue’ and ‘Misato Purple’ don’t need any attention at all.

Sedum ‘Autumn Joy’ (zone 3 – sun)
‘Autumn Joy’ is a joy: the only way you can go wrong with this plant is to give it too much water or fertilizer. Plant it in well-drained soil and keep it on a lean diet, and this Sedum will form a mound that looks stylish from the minute it pokes out of the ground in the spring until the dried heads hold frost in December. Flowers buds are white in July, turn pink in August and rusty-red in October.

Stokesia laevis (Stokes aster – zone 5 – sun)
Stokes asters bloom in mid-summer and grow to between two to three feet tall depending on the variety. Available in purple, blue, white and yellow, this perennial is the perfect plant to combine with daylilies. Deadheading improves the plant’s appearance after flowering.

Originally published in “The Connecticut Gardener” http://www.conngardener.com.

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