Selecting, Planting and Caring for Peonies

We offer both herbaceous and woody (or tree) forms of peonies. The most familiar garden peonies are the herbaceous types, with showy and colorful flowers in May to June, depending upon the variety. Each blooms for a week or more. They are cut down to the ground each fall and rise again in the spring.

Tree peonies maintain woody stems which bear large leaves that drop in the fall, and their flowers are enormous: often up to ten inches across! These blossoms open and fade all too quickly, especially when grown in afternoon sun (although they need at least ½ day of sun to bloom well.) Thanks to the late breeder Mr. Itoh, there are also many “Itoh” or “intersectional” hybrids now available, which have both an herbaceous and a woody parent. These are some of the finest peonies available, with herbaceous foliage resembling that of their woody parent. Enhanced vigor and a longer bloom period, including varieties with yellow flowers, distinguish them from other peonies.

Peonies in The Mixed Border's garden

Flowers are typically classified as Single, which have showy petals surrounding functional carpels and golden-yellow stamens (reproductive parts); Japanese, with large outer petals and clusters of enlarged anthers sometimes edged in yellow; Semi-double, in which inner petals have formed within the ring of outer petals, and still contain functional reproductive parts; and Doubles, whose stamens and carpels have been transformed into a dense display of petaloids surrounded by the outer petals. With the large number of varieties in cultivation, there is often some overlap of these various forms, but I have tried to keep it simple. The Singles and the Japanese forms will tend to remain upright in flower, while the heavier Doubles may flop under their own weight. Support of these types may be recommended to keep the flowers off the ground; a subtle corset of bamboo canes and garden twine is usually enough. Peonies usually require a couple years to get established after planting to display their full floral qualities. Flower color can be affected by strong sun (fading of deeper colors) or cool weather (white varieties can develop pink tones.)

Most (but not all) peonies are fragrant, with the pink or white doubles usually your best bet for a scent that is typically rose-like. Red peonies, though pretty in the garden, don’t always make the best cut flowers, as their aroma isn’t always desirable. Some tree peonies are mildly lemon-scented.

Peony 'Krinkled White'

How to plant peonies:

As long as the planting site is well-chosen and well-prepared, Peonies will live for many decades with little care. Hybrid peonies perform best with at least a half day of full sun, and excepting tree peonies, more is better. If given the choice, some afternoon shade can help to reduce blooms fading in color or “going by” too quickly.

Well-drained soil is important, as areas which remain wet for periods of time may cause their thick and fleshy roots to rot. Because they are so long-lived, they deserve and need a planting hole that is deep and wide, and contains a good amount of organic matter such as compost. Dig a hole at least the size of a 5-gallon bucket and remove the soil, discarding any sand or gravel and reserving the topsoil or loam. To that, add an equal amount of compost (avoid all but extremely well-aged manure) and a handful of lime and organic fertilizer. Fill the hole with this mixture, such that the plant’s soil surface will be at (or slightly above) the soil level outside the hole. Take care not to place soil on top of the roots, either now or at some future time, as their flower buds will not form if planted too deeply. Mulch very lightly with good compost or a thin layer of shredded bark, and water well.

Do not allow the plant to dry out until well-established (usually within one year.) Peonies are drought-tolerant, but may go dormant early and flower poorly (if at all) the next year if not kept reasonably moist throughout the growing season. Fertilize each spring or fall with organic fertilizer.

Peony 'Sorbet'

Peony problems:

My peony doesn’t flower. Why? Peonies planted too deeply may not flower, nor will those grown in poor soil or shade. Keep the foliage vigorous and healthy.

Some of the leaves and flower stems have wilted and turned brown. Botrytis is a blight disease of peonies that happens most often when the foliage remains moist, sometimes due to rainy weather, or because of overhead irrigation (typically from lawn sprinklers.) Clip off the diseased parts, cleaning your clippers with rubbing alcohol between cuts. Throw the diseased stems in the trash. If needed, an appropriate fungicide may be applied as a preventative (but they rarely are curative.)

Azalea or Rhododendron?

Forsythias, those cheerful harbingers of spring (but certainly not the first woody plants to bloom) are completing their annual gaudy display, and as they fade into their seasonal greenness, our eyes fall upon the bright mauve-purple blossoms seemingly as common as Forsythia – the PJMs. These rugged evergreens with smallish oval-shaped leaves are thought of by many as azaleas, but they are not. They are Rhododendrons.

It is easy to understand the confusion, because they are related. All azaleas are Rhododendrons, but not all Rhododendrons are azaleas (they are botanically differentiated by the number of stamens each flower carries: azaleas have five, while Rhododendrons bear ten or more.) And azaleas are grouped within the genus Rhododendron, and part of the larger heath family which also includes heathers, blueberries and cranberries, mountain laurels, and more – all prefer cool, moist acidic soil, so mulches are always helpful (see my previous article.) Rhododendrons (not azaleas) can be divided into 2 categories: large-leaved and small-leaved types, and the PJM belongs to the latter group. Generally speaking, those with large leaves prefer some shade, although they flower better if given at least 1/2 day of sun, and the small-leaved Rhododendrons perform best in full sun, but tolerate some shade.

Those familiar with azaleas know them to bear bright red, pink, purple or white flowers on spreading bushes that remain semi-evergreen in the winter. These types perform better in more southerly locations, but can be found locally each spring when in bloom. They generally need careful siting to prevent the crisping of their foliage in our cold and dry winter air. Deciduous azaleas are far more reliable, and have a much greater range of flower color – from white to yellow, orange to red, but no blue or purple. And rather than having the narrow bloom times of the semi-evergreen varieties, by choosing different deciduous types, one can have flowers from April to August.

Rhododendron ‘PJM’ was hybridized in the 1930’s by the late Ed Mezitt of Weston Nurseries in Massachusetts, and he named it after the initial letters of his father, who founded the nursery. This fortuitous marriage of an Asian species and an American native has become the benchmark of hardy rhododendrons, and it is very hardy. It is also quite easy to grow, thriving in full sun to part shade. Its only downfall is soggy soil, as it leads to root rot. Indeed, its ease of growth has made it as common as lilac and forsythia in the northeast, and combines well with some Magnolias which bloom at the same time.

Because its purply color can be a bit jarring in the landscape, Ed Mezitt continued to breed rhododendrons in search of calmer pinks and whites, but also a true red (which he never achieved in his small-leaved hybrids, but came close with ‘Landmark’, one of my favorites.) The varieties ‘Olga Mezitt’ and ‘Aglo’ (Olga spelled backwards) are nearly as popular as the PJM, and bloom about a week or so later, nearly in concert with crabtrees. Their showy flowers are a clearer pink, but their habit is a bit more “open” than the denser ‘PJM’. These varieties, as well as many others including ‘PJM’ have deep green foliage that is aromatic when brushed against, and which turns dark bronze to mahogany when the colder weather arrives in the fall.

Mezitt’s breeding work also included azaleas, and he used the rich palette of deciduous species native to New England and the Northeast in his work, as well as a hardy semi-evergreen species from Korea. The deciduous hybrids are outstanding, because most bloom in early to mid-summer. (A future article will cover these superb “Summer Blooming Azaleas.”) Further reasons to grow these types: they are often sweetly fragrant, and many have vivid fall foliage, extending their season of beauty. Although his semi-evergreen introductions are less well-known (and hence not easy to find,) they generally perform better in central New England than those more commonly available, because that is where they were bred and tested.

Large-leaved Rhododendrons will soon be blooming in May. Although there are hundreds of varieties hardy for our area, most nurseries and garden centers stock relatively few. Because they are frequently used as “foundation plants”, it’s best to look for varieties which remain naturally compact, rather than dealing with green monsters which can quickly swallow up a window. Look for a discussion in an upcoming issue of some of the lesser-known varieties which I consider to be better in many respects from the traditional offerings.

Hazels and Hellebores – the Flowers of Early Spring

Winter can seem interminable to the New England gardener, with the possibility of snow from October to April. By March, we are desperate to see the inky brushstrokes of branches against the white sheet of snow become transformed into the verdant watercolor that is spring. We long for green. We long for flowers.


Hamamelis intermedia 'Pallida'

For those who think that Forsythias and crocuses are the floral harbingers of spring, they are late to the party. Witch Hazels (Hamamelis) have been blooming in our gardens since the end of February, and will continue for weeks to come. They are the earliest woody plants to bloom where they are hardy (USDA Zone 5). Although of exotic origin, they are related to our native Witch Hazel (Hamamelis virginiana), which unfurls its pale yellow ribbon-like petals in October and November.

The spring-bloomers are ornamentally superior to the native Witch Hazel. Their flowers are far showier, and hybridization has resulted in colors ranging from soft yellow to brassier tones, and even orangey-reds. Most are fragrant, adding to their charm, and an armload of branches brought into the house will scent the air with sweetness. The variety ‘Arnold’s Promise’ has long been my favorite, with its bright lemony-yellow blossoms.


Hamamelis intermedia 'Pallida' flowering with snow still on the ground

Whether in bloom or in size, these are not timid shrubs. They’ll flower dependably, beginning in late February or early March, even in the snow. Each year they’ll grow larger, eventually reaching twenty feet or more in height, with a wide spread. I think they are excellent choices for a sunny corner of the house, or at the edge of a woodland garden, as Witch Hazels can tolerate a little shade. Plant some Snowdrop bulbs (Galanthus) beneath one in the fall, and you will be rewarded with your own flower show each year.


Corylopsis spicata 'Golden Spring' in bloom

Forsythias can be troublesome shrubs, as they often grow ungainly without proper pruning. A better choice might be Winter Hazel (Corylopsis spicata), which as I write this in late March, is just coming into bloom. The flowers are a lovely shade of soft yellow, and are carried on stems that are much more elegant than the common Forsythia. Although reported to be hardy only to Zone 6, we have been growing Winter Hazel in our Zone 5 gardens for the past 20 years with little or no winter damage. The pleated, bluish-green leaves remain attractive all season. We have a chartreuse-foliaged one planted in our garden (C. spicata ‘Golden Spring’,) and hope to offer this variety for sale soon. All benefit from a little shade, especially in the afternoon.


Hellebore hybrid

Lenten Rose, or Hellebore (Helleborus), have long been appreciated in Europe for their early blooms that defy cold weather. Over recent years, they have gained a following in the US, and there has been much breeding work done to produce a virtual rainbow of colors and “doubled” flowers. Our Hellebores started to emerge from the ground once the snow melted, and a week of unusually mild weather has brought their flowering stalks to attention, while catching ours. If snow were to fall on them, it’s no matter, as they will patiently wait for it to melt and reveal their long-lasting blooms. Placing Hellebores under a deciduous tree or shrub will give them sun early in the season, and shade later. The foliage is leathery yet quite handsome, and effective all season. I like to clip off last year’s foliage in the early spring, to give room for the new shoots.


Helleborus 'Blue Lady'

It’s little wonder why these superb plants are rarely seen in gardens. Often, they have finished blooming before gardeners seeking springtime cheer are visiting nurseries – all the more reason to do some homework before making a plant purchase, rather than buying what’s in flower. To have four-season interest in your garden requires planning, and patience. To quote W. E. Johns, “One of the most delightful things about a garden is the anticipation it provides.”


Helleborus 'White Spotted Lady'