Tag: tree peony

  • How and when to plant peonies

    How and when to plant peonies

    Whether you’re planting bulbs, trees or perennials, the best time to do so is when they’re dormant – before they begin their active growth. The optimal planting time depends on what you’re planting. Perennial plants are best planted in spring, but it’s better to plant peonies in the fall.

    Peony root (Photos by Dugald Cameron)
    Peony root (Photos by Dugald Cameron)

    Why it’s best to plant peonies in the fall

    Peonies are available as growing, potted plants in spring, but this has more to do with satisfying the demands of the market than what’s best for your peony. Not that they can’t be successfully spring planted, but you run a fair risk of disappointing results. Besides, the selection from peony nurseries in the fall is much larger. Considering how long they live and how few most of us will plant in our lifetime, why not do it right? Don’t be surprised to spend more that $30 for a good variety. They’re worth it and for heaven’s sake what else can you grow and enjoy for the rest of your life for so little?

    A freshly dug peony root.
    A freshly dug peony root.

    Herbaceous peonies

    Herbaceous peonies are by far the best known and beloved. They like a fertile soil, but tolerate a range of types provided they drain well. A minimum of six hours of sun is best. Nurseries lift their peony roots in the fall, dividing them into pieces. Each piece should have three to five “eyes”. These eyes will produce next year’s stems and flowers. Peonies don’t like being moved around, so choose your planting site carefully, considering the sunlight and your peony’s mature size. Give them room. Small as that root looks now, it will get much bigger.

    Easy as they are to grow, there is one critical factor that must be addressed when planting – the depth of the root. Actually, it’s the depth of the eyes that matters. If planted too deeply, your peony may not flower for many, many years. It will grow, but not flower. These eyes are the pink or white buds you’ll see at the top of the root (crown). Dig a hole larger than your root and orient the root so that the eyes are roughly on one plane. Hold the plant carefully in the hole and fill in the soil, making sure the eyes are 1 1/2 to two inches (3 to 5 cm) below soil level. Chances are you may have piled the excavated soil next to your hole which makes this measurement tricky, so I place the excavated soil elsewhere and lay the handle of my spade across the hole to show the soil level. Novice gardeners sometimes mistake the thick roots for stems, planting the crown upside down. There shouldn’t be any part of the root showing above ground when you’ve finished. Tamp the soil down gently. There’s no need to water unless you don’t expect any rainfall before winter.

    The problem with planting potted peonies in the spring is that there are no eyes visible, just the growing stems. The eyes may or may not be at the right depth in the pot. Without seeing the eyes you won’t know where they are when you put your potted peony into the garden. Besides, the selection is huge in the fall, the prices cheaper and many specialty peony nurseries only ship bare root in the fall.

    Tree peonies

    Unlike herbaceous peonies, tree peonies don’t die back to the ground every winter. They’re equally long lived, but their woody branches remain above ground in winter. They, too, like lots of sun, but light-coloured varieties like light dappled shade at midday to keep them from fading. Five hours of sun will probably do. Tree peonies also hate being moved and they grow larger than their herbaceous cousins so give careful thought to their site. Give them a fertile, well-drained soil. They were first hybridized in China (their native country) and Japan, but there are also many fabulous North American hybrids.

    Tree peonies are grafted to an herbaceous rootstock. They can’t readily be divided so grafting is the easiest and most economical way to produce them. This isn’t an easy or quick process. The graft should be a few years old and the plants have several branches. A good tree peony can cost over $100, not bad considering they sold for their weight in gold in imperial Japan centuries ago. Their spectacularly crepe-textured flowers come is a wide range of colours, often with contrasting flares, and bloom before their herbaceous cousins. They can be purchased potted in the spring and can certainly be planted then, but experience still strongly suggests bare root, fall planting is best because, unlike potted plants, their roots haven’t been cut off to fit in a pot. Bigger roots will give you a bigger, better plant.

    You’ll need a hole big enough to accommodate the roots and deep enough to situate the graft a minimum of six inches (15 cm) below soil level. The reason for this is threefold. First, it encourages the tree peony to grow its own roots, overtaking the grafted herbaceous rootstock. The second is to ensure that there’s enough of your precious tree peony to grow back should it ever be broken off at ground level. Thirdly, it discourages the rootstock from producing its own foliage and overtaking the tree peony grafted to it. Keep an eye out for non-woody stems with different foliage. If you see them, just dig down and cut them off where they join the root. 

    Itoh hybrids

    I wouldn’t be surprised if you’ve never heard of Itoh hybrids. They first came to North America from Japan in 1963, so are a relative newbie to the peony world. In 1948 the gifted Toichi Itoh successfully crossed an herbaceous peony with a tree peony. From the initial 36 seedlings have come the many varieties we have today, combining the colours and textures of the tree peony with the deciduous habit of their other herbaceous parent. They share the soil and sunlight and critical planting depth of their herbaceous parent. Fall planting is best for these, too.

    Lifted and washed peony, ready to divide.
    Lifted and washed peony, ready to divide.

    Moving peonies

    Peonies are very tough plants. I remember the first advice I got (and shared) about moving them: “Dig up the rootball being careful to minimize root disturbance.” Egads, I said when first trying to move a long-established one, discovering it had a VERY deep root system. Short of using a back hoe, there was no way I could get it all.

    All you really need is the crown and some of the roots. Just cut off the roots you can’t dig out. Wash the soil away to get a better view of the eyes. You can divide it into as many pieces as you want provided each piece has at least five eyes. I’ve also discovered that those roots still in the ground can grow back, so don’t be surprised if the original plant comes back.

    More on Garden Making about peonies:

     

  • How to prune Japanese tree peonies

    How to prune Japanese tree peonies

    Japanese tree peony (Garden Making photo)
    Japanese tree peony (Garden Making photo)

    There seems to be some correlation between pounding rain and peony blooming schedules. My two Japanese tree peonies were smacked down by heavy rain, but I did get to see their beautiful flowers for a fleeting day or so before the devastation. Now it’s time to assess their structure, which is a bit wonky from abusive weather. I suspect they don’t stand up well to the weight of snow accumulating in their interior structure, causing the woody stems to splay open. Fortunately, pruning is a good way to rejuvenate them.

    I should point out that it’s better to prune tree peonies in early spring, when their pink buds are prominent, but not yet open. But truth be known, I’ve never done this work on time, and always get to it after the flowers are just finished, usually in early June.

    Their branches live for about four years, and are replaced by new wood that sprouts every year. This natural renewal process saves quite a bit of anxiety when it comes to pruning. It’s only necessary to cut out obviously dead wood, either entire branches (cut back to the crown), or upper sections and side twigs of living branches (remove only the dead sections), cutting to just above a living bud. The end result should leave every branch with a living bud at the top. (Herbaceous peonies behave differently: their stems die back to the ground each winter and the plant sprouts new growth in the spring.)

    But my tree peonies have living wood splayed open, with some branches in an almost horizontal position. As buds sprout, the weight of upward-facing new growth has no proper support and falls sideways. Flowers end up on the ground and it’s a mess! What I’ve learned is that Japanese peonies have many buds along their branches, both those that are visible and other adventitious buds hidden in the thin bark. The plants are quite responsive to pruning, and will activate their buds when living sections are removed. I just do what’s necessary, and remove any branches that aren’t sufficiently perpendicular, shaping the plant into an open form with branches leaning slightly outward and pointing upward. Taking off living wood means I’m losing some of next year’s flower buds, but the plant is quick to open buds and make new shoots.

    My tree peonies got into such a mess because I was afraid to prune them. Now I see that it’s easily done, and the plants are quick to come back with new growth. So take courage and just do it.

    More on how to grow peony plants

    How and when to start peony plants

  • Tree peonies and their kin

    Tree peonies and their kin

    Mauve tree peony (Photo by Brendan Zwelling)
    Mauve tree peony (Photo by Brendan Zwelling)

    The natural elements can be cruel. The fabulous, 10-inch (25-cm) blossoms on my mauve tree peony (Paeonia suffruticosa, Zone 5) are all smashed up, the result of an unpredicted heavy rain one recent evening. That was certainly a low blow to a gardener who, with a little advance notice, would gladly have stood there holding an umbrella over the blooms during the deluge. That would be easy gratitude for the pleasure they give me.

    The flowers of tree peonies are startling huge and beautiful (and some are deeply scented), and their foliage remains attractive all season. The Irish gardener and horticultural writer William Robinson (1838-1935) grew many tree peonies, and suggested spotting them throughout perennial borders, or giving them a display bed of their own with a low ruffle of long-blooming perennials such as the little Carpathian bellflower (Campanula carpatica, Zone 3) surrounding them.

    Tree peonies are small shrubs with woody stems that remain through winter. They’re usually self-supporting, although it’s been my experience that they get a bit lax and floppy when grown in low light and sometimes require staking. Tree peonies will flower in part shade, but more blossoms and stiffer stems are produced in sunny locations. They’re grafted on rootstocks of species herbaceous peonies, and occasionally the rootstock sends up a stem with leaves noticeably different from the tree peony. Cut out any rogue stems coming from below ground as low as possible, otherwise they can overwhelm the grafted plant above.

    I also have several herbaceous peonies inherited with my garden, including double pink ‘Sarah Bernhardt’ and single white ‘Jan Van Leeuwen’ with a centre of thick yellow stamens (and delicious lemon scent). When the flowers are finished, their foliage takes up more space than I want to give them. I know the leaves are working all summer to store energy for next year’s flowers, but I don’t think it hurts to eliminate up to 25 per cent of the stems, cutting from the outer edges of the plant, to reduce its bulk. So far this method of controlling their size hasn’t reduced flowering.

    A new category is intersectional peonies (sometimes referred to as Itoh peonies), the result of crossing herbaceous and tree peonies. Intersectional peonies die to the ground in winter, but their flowers and foliage are quite like tree peonies, and colour choices include yellow, unknown in herbaceous peonies. This innovative breed of peony strikes me as a good opportunity to begin a new collection (My acquisitive spirit perks up!), and I think they would make a superb double-bordered peony walk. Once the flowers are finished, the ornamental foliage would continue to enhance both sides of a pathway for the rest of the growing season. This seems the ideal combination of peony attributes, and my compliments to the clever plant breeder who thought of this.

    Time to prune lilacs

    'Agincourt Beauty' lilac (Garden Making photo)
    ‘Agincourt Beauty’ lilac (Garden Making photo)

    The lilacs have been terrific this year, their flowers lasting so well in the cool, moist spring conditions. Lilac season begins with the early Syringa x hyacinthiflora cultivars, including Canadian-bred lavender-pink ‘Asessippi’ and violet-purple ‘Pocahontas’. These are followed by the S. vulgaris French hybrids, a large category with familiar named plants like purple ‘Agincourt Beauty’ and white ‘Madame Lemoine’. The latest to flower are the Preston lilacs (S. x prestoniae), another group of plants bred in Canada, and including my bright pink ‘Miss Canada’, currently blooming in the front garden. The Preston lilacs are particularly vigorous shrubs, with large flower trusses, and a distinct scent of privet inherited from ancient genes. If you’re expecting the usual lilac perfume, the Preston plants will surprise you.

    The French hybrid lilacs in my back garden have become quite leggy, and some have reached 15 feet (4.5 m) in height, with all the flowers coming at the top. This is very nice for my neighbour’s second-floor balcony, but it’s not as satisfying for me down below in the garden. It’s time to lower the height on these plants, and the pruning must be done immediately after flowering is finished to avoid sacrificing next year’s flower buds. There’s no time to waste!

    The basic approach is simple, and focuses on rejuvenating the plants by removing up to one-third of the stems each year, for three years, and stimulating new stems that will eventually carry flowers. Lilacs bloom best on younger wood, so I’ll begin with the oldest stems that have grown more than two inches (5 cm) thick. I’ll also take out anything that’s broken, or weak and twiggy. Lilacs react quickly to pruning, sending up suckers from the base. That’s a good thing, as the strongest of these will be the ones to save and develop into a well-shaped shrub. I’ll save three or four of the best suckers, and eliminate the rest. I’m aiming for a plant about eight feet (2.5 m) tall, with flowers blooming at all levels. It may take a few years to bring these tall lilacs back to a more manageable size, and the strong new sprouts from underground will bloom in three to four years. Lilacs need shaping every year to ensure there is always vigorous new wood developing, while older stems are removed. That’s the way to disappoint the neighbours and keep lilacs blooming where I can see them.

    Thanks for visiting at Making a Garden.

     

Advertisements
Clicky