Karl Rosenfield peony variety guide and growing tips

Disclosure: This article may contain affiliate links, meaning we may earn a small commission if readers purchase products through these links. As an Amazon Associate, we earn commission from qualifying purchases.

The Karl Rosenfield Peony is one of the most deeply-colored, dramatic peonies in the garden. Fortunately, they’re also incredibly easy to grow!

Karl Rosenfield peony is an herbaceous peony with large, deep-red, fluffy double blooms. These hardy perennial plants grow to be 32″-38″ tall with ornamental green foliage. The large blooms can reach 6″-7″ wide each on established plants and make wonderful cut flowers for bouquets. The Karl Rosenfield Peony is a cultivar of Paeonia lactiflora bred in Nebraska by John Rosenfield and introduced in 1908.

Keep reading to learn how to grow Karl Rosenfield peonies.

Karl rosenfield peony
Karl rosenfield peony

Karl Rosenfield peony basics

Paeonia lactiflora ‘Karl Rosenfield’ was bred by John Rosenfield and introduced in 1908. Mr. Rosenfield named his new peony cultivar after his son. Mr. Rosenfield bred peonies in his greenhouses located in West Point, and later in Omaha, Nebraska.

John Rosenfield is known in the gardening world for introducing dozens of peonies, including the popular Floral Treasure peony. The Karl Rosenfield Peony remains one of the most popular varieties of peonies in gardens around America today. This peony is sometimes called the “Karl Rosenfeld” peony, as the breeder’s last name was “Rosenfeld” (meaning “rose field” in German) before he anglicized it to “Rosenfield”.

The Karl Rosenfield peony is a herbaceous peony cultivar, otherwise known as a soft-stemmed peony. It is a very shrubby plant, so it looks like a type of shrub during the early spring and late summer months when the blossoms have not yet appeared.

Karl Rosenfield peonies are often crimson-red in color, although some people find they are dark pink. The color of the blooms can vary depending on the growing conditions of individual plants. Karl Rosenfield peonies are very attractive to butterflies and are very fragrant. If you enjoy seeing color and butterflies in your garden, it is a good idea to plant Karl Rosenfield peonies.

The Karl Rosenfield Peony is a good example of a “double” peony – one that has multiple layers of petals to form that classic puffball shape. Other popular double peonies include Sarah Bernhardt Peony, Festiva Maxima Peony, and Shirley Temple Peony.

What type of peony is Karl Rosenfield peony classified as?

Karl Rosenfield Peony plants (Paeonia lactifloraKarl Rosenfield’) are herbaceous perennial peony plants with Full Double-type peony flowers that bloom mid-season (mid-late spring).

Peonies come in six main types of flower forms: Single, Anemone, Japanese, Semi-Double, Bombe, and Full Double. Full Double peonies like Karl Rosenfield are known for their voluminous layers of petals. In this flower type, all stamens and carpels are transformed into petals. Double peonies look like a flower inside a flower (hence the term “double”).

There are three main types of peony plants: tree, herbaceous, and intersectional. Karl Rosenfield Peonies are among the herbaceous category of peony plants. These plants sprout anew from their roots each spring, and will typically grow to be about 3 feet tall by the middle of spring. Then, they will bloom and go on to display beautiful foliage throughout summer and even into early fall. They usually die back to their roots after the first hard frost comes.

Karl rosenfield peony

How tall do Karl Rosenfield peonies grow?

Karl Rosenfield peonies grow to be about 3 feet tall – generally in the range of 32″-38″ in height. They are mid-sized perennial flowers in the garden, and during most of the year, they look like shrubs. If you want to have large flowers in your garden, but also want to have pretty shrub-like foliage in the summer, then Karl Rosenfield peonies are a great flower to plant in your garden.

When do Karl Rosenfield peonies bloom?

Karl Rosenfield peonies typically bloom in mid-late spring, depending on the temperatures and weather conditions in your area. If the area that you live in is warmer, they will bloom during the middle of the spring. If you live in an area with slightly colder temperatures, they will likely bloom during the early summer.

How Long Do Karl Rosenfield Peonies Bloom?

Karl Rosenfield peonies typically bloom for 7-10 days, although they sometimes bloom for longer. These herbaceous perennial plants bloom only once per year (in the spring).

Although Karl Rosenfield peonies only bloom for a little over a week, they look good for most of the year. After the Karl Rosenfield peony finishes blooming, the blossoms fall off or are removed and the foliage of the plant is left. During the late summer and early fall months, the foliage is green and adds some needed color to your garden. During the winter, after the plant is frosted over, the leaves turn green and the plant seems to shrink. The leaves may turn brown after it dies for the winter, but often they actually turn red.

Karl rosenfield peony plant
Karl rosenfield peony plant

Do Karl Rosenfield peonies need support?

Karl Rosenfield peonies do sometimes need support, especially when the blossoms are in full bloom. You should add support to the Karl Rosenfield peonies that are in your garden early on in the spring after the soil has become soft again. If you add support to the Karl Rosenfield peonies, they will grow and thrive, and the blossoms will not droop toward the ground.

Use stakes or peony support rings. Place the peony support rings underneath the blossoms before they bloom to keep them from drooping to the ground. The peony can be gently fastened to a stake or held up with the peony support ring, so with careful placement, you will not be able to see them soon after you place them.

How do you plant a bare-root Karl Rosenfield peony?

When you plant a bare root of a Karl Rosenfield peony, do it early on in the fall season if possible. You can plant it during the early spring, but you may not see the blossoms bloom until the next spring, depending on how the plant does. Karl Rosenfield peonies do not do well when they have been moved, so choose the planting spot carefully.

When you plant a bare root of a Karl Rosenfield peony, dig a hole that is about twice as wide as the root, but not terribly deep. While you’re digging the planting hole, soak the peony root in clean water to hydrate it prior to planting. Peony roots can be soaked for 20 minutes – 4 hours, depending on how dry they are.

Place the Karl Rosenfield peony root in the hole, making sure that the creamy-pink “eyes” (the flower buds) are facing upwards towards the sky. Backfill the hole with the soil that came out and cover the root up with dirt. Make sure to pack the soil tightly around the roots, but do so gently so you do not harm them in any way. Water the newly-planted peony deeply after planting.

Karl rosenfield peony

How far apart do I plant Karl Rosenfield peonies?

You should plant Karl Rosenfield peonies about 2 feet away from each other, although you can plant them further apart if space allows. The roots of Karl Rosenfield peonies need plenty of room to spread without running into any other roots to grow and thrive. Peonies do not do well when they have to compete for nutrients with other plants and flowers.

Karl rosenfield peony
Mary Jane Duford
Mary Jane Duford

Mary Jane Duford is a gardening expert and founder of Home for the Harvest. She's also a professional engineer, certified permaculture garden designer, and master gardener in training. Mary Jane has been featured by publications such as Real Simple, Mother Earth News, Homes & Gardens, Heirloom Gardener, and Family Handyman.