Marshmallow plants are large, summer-flowering perennials with a fascinating culinary and medicinal history.
Its white to pale pink blooms appear along the stems from mid-summer until early fall.
Where to Plant Marshmallow
Grow marshmallow in any sunny garden where consistent soil moisture can be maintained.
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Less than six hours of direct sun results in fewer flowers.
Choose an area with adequate moisture, especially while the plant establishes itself.
It tolerates cold and can be grown inUSDA Zones3 to 9.
Credit: Peter Krumhardt
Marshmallows soft white or pale pink blooms combine easily with a wide variety of perennials.
It is also a good choice for arain gardenwhere soils intermittently experience a lot of moisture.
However, marshmallow doesnt grow well in constantly standing water.
Credit: Dean Schoeppner
How and When to Plant Marshmallow
Sow marshmallow seeds outdoors in the fall or spring.
Spring-sown seed requires a period ofcold stratification(refrigeration for several weeks) to break its dormancy.
Fall-sown seed doesnt need refrigeration since it experiences cold temperatures outdoors.
Credit: Lynn Karlin
Plant four to five seeds together, spacing each group 24 to 30 inches apart.
After the seedlings are several inches tall, remove all but the strongest from each group.
Water seedlings consistently for the first growing season.
Light
Marshmallow thrives inat least six hours of full sun per day.
Less sun results in fewer flowers.
Well-established plants tolerate short periods of dry soil.
Excessive heat, particularly when combined with low humidity, can cause the plants to wilt.
Fertilizer
If youadd organic matter to the soilbefore planting, no additional fertilizer is usually necessary.
A dilute solution of aliquid fertilizerworks well.
Pruning
Pruning is not usually necessary with marshmallows.
Removing spent flowers keeps the plants looking their best.
If you have a severe infestation, useneem oil.
The first signs of the disease are light-colored spots on the underside of lower leaves.
The spots turn reddish-orange as spores form.
Eventually, the spots turn black.
Rust weakens plants and detracts from their appearance.
Copper fungicides are also effective for treating infected plants.
How to Propagate Marshmallow Plants
Marshmallow plants can be propagated by seed or division.
Seed
Marshmallow self-seeds unless theflowers are dead-headed.
Seed propagation is the most common method of obtaining new marshmallow plants.
The seeds are rarely carried in garden centers but are available online.
Marshmallow seed requires a cold stratification period to break its dormancy and germinate.
Seed that is sown in the fall receives the cold naturally.
you’re able to also sow the seeds in pots filled with seed-starting mix.
Division
Marshmallow plants can be divided.
Dig the plants in late fall or early spring before new growth appears.
Lift the entire root system of the plant.
Using a sharp spade, cut it into sections.
Replant each section, water well, and apply a 2- to 4-inch layer of mulch around the plants.
Ranunculus
Several species and varieties ofranunculus(Ranunculusspp.)
boast lovely flowers, usually with crepe-paper-like petals.
Some are ground-hugging, while others are upright.
The upright types bloom in spring and early summer.
They’re hardy in Zones 8-11; dig up the corms in colder areas and replant in spring.
Its flower seasoning and color work well with marshmallow.
Turtlehead is native to the southeastern United States, and hardy in Zones 3-9.
Swamp Milkweed
Swamp milkweed(Asclepias incarnata)is another North American native.
Its flowers attract butterflies and hummingbirds, and its leaves serve as food for the larvae of monarch butterflies.
It’s hardy in Zones 3-9.
Fertilizing with too much nitrogen is also a possible reason for the lack of flowers.
Although a few volunteer seedlings might appear near your marshmallow plant, they are not considered invasive.
Fall is the best time to harvest the roots.
Dig up the whole plant and remove some of the fleshy roots before replanting the remaining clump.
The fresh roots can be washed and peeled for use as a vegetable in soups and stews.
