Tree Peonies vs. Herbaceous Peonies

Few flowers can elicit as much cheer as Peony Roses, or Peonies, as they are more affectionately named. Known for their bright, luscious and colourful roses, as well as their hardiness, peonies are a staple in gardens, vases, and bouquets, and they can easily be used for a number of decorative purposes.

Two common types of peonies include tree and herbaceous varieties, and while both peonies produce the vibrant roses we all love, there are a few key differences between the two that are important to consider before planting them or buying them for display in your home.

Peony Foliage and Flowers

Tree peonies are shrubby plants that can grow to 1.5 metres in height in width, though some can reach twice that height. Herbaceous peonies are smaller growing plants, usually reaching between 0.5 and 1 metre in height and forming a bush. Mature herbaceous peonies may have 40 or more roses, while mature tree peonies can grow more than 100.

The key difference between tree and herbaceous peonies is how they produce their foliage. Tree peonies retain their above-ground woody stems year round, even after the flowers and branches have dropped, whereas herbaceous peonies are perennials. They die back into the ground each winter and resprout in the spring, usually flowering in mid to late November (tree peonies usually bloom about two weeks earlier). Herbaceous peonies produce their flowers by growing long stems topped by fat buds, which open into large flowers.

A beautiful example of a Herbaceous Peony Rose

Tree peonies are slow to mature, and it may take three years before they have an established flower. Once they are grown, however, they may live for over 100 years. They have much larger and flatter flower buds than herbaceous peonies, which are the same colour as the leaves, and their bud tips do not secrete honey. Their flowers can grow up to 25 centimetres in diameter once they blossom, whereas the roses on herbaceous peonies are usually 15 centimetres in diameter.

Both tree and herbaceous peonies come in single and double forms. Single peonies have only one or two rows of petals, and their centre stamens are always visible. This variation does not require staking. Double peonies have an abundance of petals, form a dome shape once fully open so they resemble a pompom. This luscious variation may need staking.

While pink peonies are perhaps the most recognisable, the flowers actually come in a rainbow of colours, including white, rose, and red. Tree peonies expand the palette even further, coming in shares of coral, deep purple, mahogany, and bright yellow. Some tree peonies are even bicolored, blending red with white or tints of purple.

A white Tree Peony in full bloom

Climate

Herbaceous peonies can only grow in cool climates, as they need the cold to trigger the development of their flower bud. Therefore, in Australia, they are often found in Tasmania, Victoria, and the mountain district, where the winters are cold. Tree peonies also prefer cold climates, but they will also grow in cooler temperate areas, so they are a good option if you are struggling to successfully grow herbaceous peonies.

Herbaceous peonies grow best when they receive at least four to five hours of full sun each day but are protected by the strongest sun in the afternoon by shade. Tree peonies can also be grown in full sun, and like herbaceous peonies, they enjoy shade from the harshest rays during the afternoon.

A crop of pre-bloomed herbaceous Peonies

Tree peonies should be planted away from the roots of other plants so they have room to grow. They prefer fertile but well-drained soil surrounded by open air to prevent fungal diseases, and they do well with ample organic matter, such as bone meal.

Herbaceous peonies will grow in most soils as long as they don’t stay wet, but they prefer rich, heavy soils such as clay. They can be grown next to each other or among other plants.

Peony Maintenance

Overall, peonies are relatively hardy and low-maintenance flowers that are not overly susceptible to pests, deer or disease. However, if you want to help your peonies achieve their full potential, there are a few steps you can take to help them along.

Tight bunches of cut Herbaceous peonies just in from the market

Herbaceous peonies may benefit from a three-legged metal wire frame as they grow to help support the stems. You should be able to find one of these at your local gardening store. Allow the foliage to die naturally in late fall, and then start pruning.

Tree peonies, on the other hand, should only be pruned to remove dead or broken branches when the growing season starts. Additional maintenance may include adding a layer of compost or manure to the soil in the spring to give them some extra nutrition as they prepare to blossom.

Styling your Tree and Herbaceous Peonies

Whether you are planting peonies in your garden, incorporating them into your landscape design, or cutting them for display in your home, the bright and fragrant roses will enliven any indoor or outdoor space.

Herbaceous peonies are the type most often used as cut flowers, and they are the best to use in floral arrangements, as they are long-stemmed (other varieties are relatively short-stemmed, but they can still make good displays when snipped in full bloom and floated in a shallow bowl of water).

Our Zoey bouquet is always a favourite with Peony lovers

You can pick both herbaceous peony blossoms and buds for display in your home. When you are picking peony blossoms, it is best to do so in the early morning, before they are warmed by the sun. Cut them as early as possible, making sure to leave a 35- to 40-centimetre stem. You should also remove the extra foliage from the flower, leaving one or two leaves at the top. Herbaceous peony blossoms are susceptible to fungal disease, which will shorten their vase life, so arrange them into vases as soon as possible to avoid this.

You can also pick herbaceous peony buds before they blossom into flowers, and these should last in the refrigerator for several weeks. Once you notice the buds beginning to open and show a little colour (they should be about 3 to 4 centimetres in diameter at this point and feel almost like a marshmallow when you squeeze them), they are ready to be cut with a 40-centimetre stem. Remove the excess foliage, leaving one or two leaves at the top.

A very tight Herbaceous Peony that has just been picked

For best results, store your buds in groups of 10 or fewer, and wrap them in dry newspaper, leaving the cut stems open to assist with circulation. Then, lay your wrapped herbaceous peonies horizontally in a very cold refrigerator (but not so cold that they freeze), and replace the paper periodically if it becomes damp. Like with fresh-picked blossoms, to avoid fungal disease for your herbaceous peony buds, it is imperative to keep them cool and dry. Resist putting them in the refrigerator drawer, as this limits the air circulation they need to remain fresh.

Your herbaceous peony buds will not bloom until they are removed from the fridge and put into a warmer environment. When you are ready to display your herbaceous peony roses at home, remove the newspaper wrapping, trim the stem ends once again, and place them in a vase with cool, fresh water, submerging approximately half of their stem length. Once they are in room temperature, their petals should immediately start to unfurl, and within eight hours you will have fully open herbaceous peony roses that resemble fresh-picked flowers.

Tree peonies are not quite as suitable as cut flowers, but they can still be used for decorative purposes in outdoor landscaping, whether you want to line your driveway or simply add a pop of colour to your garden. The great thing about tree peonies is since they are deciduous, they will still display a beautiful woody branch pattern in the winter once they shed their leaves, so they work as a year-round decoration.

Notice the more transparent, refined type of petal on the Tree Peony

When you are styling your garden, driveway, or other outdoor areas, make sure you give your tree peonies plenty of space to grow. They should be kept at least 3 metres from trees and 1.5 metres from other tree peonies. Plant them in a slightly shaded area if possible, which will help prevent the flowers from fading as quickly. You can expect your tree peonies to stay in bloom for seven to 10 days, and while this is a relatively short period, the vibrancy the roses deliver more than makes up for it. The overall peony bloom season lasts for six to eight weeks, so you can extend the timeframe by planting a mixture of early- and late-season bloomers. Herbaceous peonies usually bloom one to two weeks after tree peonies (their blossoms also last for seven to 10 days), so including both varieties in your garden or outdoor landscaping will deliver even more colour each season!

Is there a winner?

Both tree and herbaceous peonies will do a wonderful job of brightening your home and garden each spring with their big, colourful roses that will continue to blossom for decades to come. Whether you plan to display cut flowers in your home or grow your own peonies, understanding the differences between these two common and beautiful varieties will set you up for success and allow you to reap the maximum benefits these wonderful flowers have to offer. Could we choose one over the other? Well unfortunately that would be like choosing a favourite child!

Kate x