Peonies need to chill, literally

Cold-loving plant species

It’s common knowledge that flowering plants require warm weather and plenty of sunlight to push out beautiful blooms.

But the peonies rather prove otherwise.

Late in the fall, right before the first frost of winter, peonies tend to ‘die back.’

When the stems and leaves on these plants begin to wither and shrivel, it indicates that they’re getting ready for their annual beauty sleep.

There are a few different types of peonies, but they’re all cold hardy:

• Herbaceous perennials, a classic addition to any garden. The herbaceous peonies are typically more resilient to extreme cold and frost than other species.
• Deciduous shrubs, often known as tree peonies, are the earliest bloomers among the peony species. The diameter of its massive blossoms can reach up to 10 inches.
• Intersectional hybrids (or Itoh peonies), a hybrid cross of herbaceous and deciduous types, thus combining the finest qualities of both parent species. Gorgeous huge blooms of tree peonies on plants with soft-stemmed foliage and shorter height of herbaceous perennials. Their massive blossoms outlast the other two varieties combined, lasting for up to three weeks.

They need their winter beauty sleep

Peonies love extended periods of chilly winter for their seasonal resting state, called dormancy.

These plants absolutely need their “chill hours” to put their energy towards developing the buds that will burst into lush, beautiful blooms in the spring and early summer.

Peonies won’t flower if they aren’t chilled properly.

It takes at least six weeks of winter dormancy at temperatures consistently below 40-45°F for herbaceous peonies to bloom again in the spring.

Thus, they are not the finest peonies for warm and temperate climates.

They grow best in cold climates (hardiness zones 3-7).

The winter dormancy phase is necessary for tree peonies, too, but the temperatures do not need to drop below freezing.

Hence, most tree peony cultivars grow well in the hardiness zones 4-8.

In fact, frost is an essential aspect of the peony plant’s life cycle. It’s beneficial to their health and their capacity to produce strong buds.

Lack of “chill time” will cause these plants to produce less foliage and smaller blooms. As long as these plants are kept within suitable hardiness zones, they should return to their stunning and healthy form when spring arrives.

But how much frost is enough?

Peonies can withstand temperatures of roughly -40°F when it comes to cold tolerance. Anything less will almost certainly cause damage to the buds, leaves, and stems.

These extraordinary plants often endure freezes of a day or two with minimal care. You may also need to prune them before winter so that the plant can produce the most buds along with potential blooms.

You may be wondering, “What if I want to grow peonies in my warm climate gardens?”

Although peonies are not always successful in mild winter areas, some brave gardeners nevertheless give them a go and end up with a lovely result.

One of their best pieces of advice is to use ice bags to induce dormancy in your peonies.

Periods of extremely cold months aren’t that necessary. The main point here is to keep the roots and buds cold.

Many warm region gardeners have succeeded with fabulous peonies by trying this tip.

But rather than pouring bags of ice, it is better to freeze two or three litres of water in plastic bottles and arrange them around the plants during the coolest three or four weeks at your location.

When these frozen water bottles thaw out, replace them with new ones. That way, you won’t establish the groundwork for any fungal disease by adding water to the area, as you would if you used the ice bag method.

In addition, your peony’s root system and subsequent flowering will be greatly influenced by the depth at which you plant it.

So, a light dusting of dirt around the roots’ “eyes” (buds) may also suffice for peonies grown in warmer climates.

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