Which plants make peonies look their best in the garden

The difference often comes down to the plants growing right beside them.

Peonies are among the favourite plants of many amateur gardeners: enormous flowers, an intense fragrance and dependable performance over many years. Yet plenty of people wonder why their own peony grows well but does not look nearly as striking in the garden as it does in a picture book. The secret is rarely the variety; it is usually the planting companions - what is placed alongside these perennials and how much room they are actually given.

What peonies need before adding companion plants

To combine peonies successfully, you first need to understand their basic preferences. This is the only way to create a healthy, long-lasting border.

• Light: Full sun to light partial shade, with at least four to five hours of direct light each day.
• Soil: Deep, nutrient-rich and well-drained; avoid waterlogging, especially during winter.
• Root competition: They dislike competing with exceptionally vigorous or shallow-spreading root systems.
• Air circulation: Leave air and a little space around every perennial, so foliage dries quickly after rain.

When leaves remain wet for too long, the risk of fungal diseases such as grey mould increases, potentially spoiling an entire flowering season. A tightly planted perennial border may look lush in its first year, but can easily turn into a damp problem area later on.

The airier the surroundings of the peonies, the more robust the plants and the more impressive the flowering will be over many years.

Basic rules for the ideal perennial border companions

Before choosing companion plants, three straightforward principles can help prevent poor combinations:

• Check site compatibility: Neighbouring plants should tolerate sun and soil conditions as well as peonies do.
• Consider height: Avoid placing plants directly in front of or beside the perennials if they will block their light.
• Keep space between plants: Always leave at least a hand’s width of clear space between clumps - preferably more.

This can appear almost too sparse at first, but it pays off by the third growing year at the latest, once peonies have reached their full size and can develop properly.

Lady’s mantle, bellflowers and more: making peonies the star

Once the essentials are right, the creative stage begins: selecting companion perennials that highlight the colour and form of peonies without crowding them.

Lady’s mantle as a living carpet

A particularly popular choice is lady’s mantle (Alchemilla). This perennial creates a low carpet of soft, rounded foliage. Above it float loose clouds of yellow-green flowers, which work beautifully with the delicate pink and white shades of peonies.

• stays low and does not deprive peonies of light
• enhances pastel shades without becoming overpowering
• makes an excellent cut-flower accompaniment in vases

In a border, lady’s mantle acts like a soft pedestal on which the large flower globes of peonies seem to sit enthroned.

Bellflowers for a delicate contrast

Bellflowers (Campanula species) add fine, bell-shaped blooms, often in violet, blue or white. Many varieties remain compact, so they do not obstruct peonies.

They share the peony’s preference for free-draining soil and full sun to partial shade. One point does need attention, however: some bellflowers are more susceptible to pests, including aphids.

Anyone adding more sensitive perennials to a peony border should combine them with fragrant “bodyguards” that keep pest insects at bay.

Hydrangeas as a calm backdrop

For structure at the rear of the border, use hydrangeas. Their rounded flower heads visually complement the weighty blooms of peonies, while providing a tranquil background in white, pink or blue.

For this pairing to work:

• plant hydrangeas slightly offset behind the peonies
• allow enough room so they do not shade the perennials
• choose a position that reasonably meets the needs of both plants

In this way, the shrubs provide gentle shade during hot months without reducing peony flowering.

Flowering sequence: colour from spring to late summer

With a careful plant selection, a border can be planned to offer colour almost continuously - before peonies bloom as well as afterwards.

Phase	Plant	Role in the border
Early spring	Allium (ornamental onion)	Spherical flowers, vertical accents and the start of the season
Spring to early summer	Iris barbata (bearded iris)	Flowers shortly before peonies, with elegant forms
Main season	Peonies	The central highlight, with large blooms and fragrance
Summer	Hemerocallis (daylily)	Takes over after the peonies, extending the period of colour

This succession prevents borders from feeling like a brief display, instead creating a considered programme across several months.

Lavender as a protective barrier: fragrance that deters pests

Lavender is an excellent visual match for peonies and offers another advantage: its powerful fragrance repels many unwanted visitors.

These include:

• mosquitoes
• flies
• fleas and mites
• some leaf-eating animals, such as deer in rural gardens

Like peonies, lavender thrives in free-draining soil and a position in full sun. It is best planted along the front edge of the border. There it forms a kind of scented fence, slowing down unwelcome insects while also clearly defining the border edge.

Lavender and peonies complement one another perfectly: the same site requirements, strong colours and added protection from pests.

Ornamental onions (Allium) work in a similar way: many insects dislike their sulphurous scent. At the same time, their spherical flower heads create distinctive visual accents among the peonies.

Plants that are poor partners for peonies

Not every attractive perennial automatically makes a suitable neighbour. Certain plant types are more likely to put peonies under pressure.

Overbearing grasses and space-hungry plants

Large, vigorous ornamental grasses can look contemporary, but are troublesome when planted close to peonies. They:

• block substantial light through their height and density
• compete for water and nutrients with strong roots
• retain moisture in the border, encouraging fungal diseases

If you do not want to go without grasses, position them well away from the peonies, such as at the rear edge of the border, and ensure there is sufficient space.

Plants for permanently wet soils

Species that prefer constantly moist or heavy soils are not ideal companions either. They encourage conditions peonies strongly dislike: waterlogged areas that remain wet for a long time and give fungi every opportunity to develop.

More vulnerable bellflowers and other perennials that are quickly attacked by pests can still be planted nearby, provided they are well framed by protective aromatic plants such as lavender and Allium.

Practical tips: how amateur gardeners can plan a harmonious peony border

Anyone redesigning an existing border or creating a new one can follow a simple rule of thumb: place the peony in the front row of leading performers, with every other plant in supporting roles around it.

• Assess the site first: Is there enough sun? Does the soil dry out? If not, improve the conditions or choose a different location.
• Maintain planting distances: Do not be misled by the first year - peonies become considerably wider.
• Set a colour scheme: Pastel shades are supported by lady’s mantle, white and soft blues; bold pink or red shades can take stronger contrasts from lavender and darker perennials.
• Use fragrance deliberately: Position lavender, Allium and other aromatic plants where pests are more common.

When planting new peonies, patience is essential: they often need two to three years to show their full potential. A well-planned setting with suitable neighbours will then ensure that the plants produce not only plenty of flowers, but truly spectacular borders.

For beginners, it is worthwhile starting with a small trial border: one or two peonies, a strip of lavender in front, lady’s mantle at the sides and a few Allium bulbs between them. This makes it easy to observe, with little effort, how strongly light, air and neighbouring plants can change the effect of these impressive perennials.