How To Grow Peonies That Make Your Neighbours Gasp!

Peonies are the unapologetic drama queens of the flower world: enormous, extravagant blooms that look as though they should have a personal assistant and their own Insta page. No-one ever looked at a peony and thought; meh.

Yet, despite their luxurious appearance, peonies are surprisingly low-maintenance. They adore frosty winters, positively sulk without enough cold, and cope with summer dryness far better than you’d expect. Treat them reasonably well and they’ll stay in the same spot for decades, becoming the sort of plant future owners point at and say, “Someone serious about gardening lived here once.”

Planting:

Autumn and early winter is the ideal time to plant bare-root peonies because it gives them all winter to establish feeder roots before spring growth begins. Potted peonies are more forgiving and can be planted at almost any time.

Peonies like sunshine and good drainage. They do not like wet feet in winter and will complain by either refusing to flower, or dying in a passive-aggressive manner. Rich soil is lovely, but they’re surprisingly tolerant of poorer soils provided they don’t sit in a swamp.

Provide plenty of space, about one square metre once mature for standard sized varieties. Peonies deeply resent competition from trees and shrubs, especially overhanging branches hogging the light and stealing moisture. They are not team players. 

Planting depth matters enormously with herbaceous peonies. Too deep and they may survive perfectly happily while refusing to flower for years out of sheer spite. For bare roots, locate the uppermost bud and plant it so the base of the bud sits about 5 cm below the soil surface. Bare roots come in a myriad of shapes and sizes  but the general rule is to plant at a slight angle rather than rammed vertically into the earth like a tent peg.

And for goodness sake,  please mark where you planted them. Every gardener thinks they’ll remember. No gardener remembers. That's why I send out every division labelled. It's up to you to poke it into the ground.

Blooms

Herbaceous peonies die down completely each autumn, only to re-emerge in spring like determined little asparagus spears with theatrical ambitions. Different varieties wake up at different times, so if one appears weeks after another, do not assume it has died dramatically in the night. It’s simply a later variety taking its time.

Most peonies flower for about two glorious weeks sometime between late October and early December. The first year may be underwhelming. You may get one stem. Possibly two. The flowers may look odd, tiny, or mildly confused. This is normal. Your peony is settling in and judging you quietly from underground.

In that first year, resist the urge to cut flowers for the house. Peony stems do not regenerate during the season, so every leaf matters. 

Once established, most varieties make magnificent cut flowers, best picked when the buds feel soft but haven’t opened yet. This is called the 'marshmallow stage'. By the third year you can cut up to a third, or at most half of the stems without causing offence. Removing the side buds gives you fewer but larger flowers. Leaving them gives a longer flowering display. It’s the floral equivalent of choosing between quality and quantity.

After flowering, it's not a bad idea to remove the spent blooms by cutting at the very top of the stem.

And now we come to a matter of grave importance:

DO NOT cut the foliage down immediately after flowering.

I repeat: do not get carried away with the secateurs.

The leaves need to stay on the plant until autumn so the plant can recharge itself for next year. Many peonies have very attractive autumn foliage which adds interest to the garden. Once the foliage yellows, you can cut it to ground level and dispose of it, which also helps reduce fungal diseases. Burning it is optional but does add a pleasingly medieval atmosphere to the garden.

TLC:

Light cultivation is usually the best weed control. Bark mulch is okay, but pea straw or compost piled around the crown can encourage botrytis, which is a fungal disease with all the charm of its name. Occasionally nice in grapes, always horrible for peonies.

Peonies appreciate fertiliser but are not greedy pigs. A balanced fertiliser, with trace elements, in late winter is sufficient. Don’t dump fertiliser directly into the planting hole unless your long-term goal is  disappointment. A handful of lime sprinkled around the crown every few years in autumn can also be beneficial.

Watering is rarely needed once established, especially if your divisions are planted at the right time. A deep soak now and then is far better than frequent shallow watering. Peonies prefer a proper drink rather than nervous little sips.

Some varieties may need staking if it rains heavily during the flowering season. One moment they’re standing proudly; the next they’re face-down in the border like someone who underestimated prosecco. Fortunately, many options now exist for peony support, and plenty of varieties hold up well to rain. Or you could just move to Canterbury.

Some varieties adapt to short term cultivation in containers, and the smaller Itohs are a good example of that. Long term though, peonies need to be in the ground, where they can send their roots deep into the cool earth.