How to Grow and Care for Japanese Andromeda

Japanese andromeda is mainly grown for the dangling racemes of bell-shaped flowers that it bears in early spring. A member of the Ericaceae family, this evergreen has a number of relatives that are also popular landscape shrubs, including rhododendrons and azaleas, mountain laurel, and winter heath. Japanese andromeda can be planted in the spring or fall. This is a slow-growing shrub that adds about 1 foot per year in moist soil under sunny conditions. Some gardeners consider the odor of Japanese andromeda flowers to be a plus, while others dislike the smell. The plant suffers from an additional drawback: it is toxic to humans and as well as pets.

Japanese Andromeda Care

Japanese Andromeda has some important needs that should be met if you want your plant to thrive. Here they are:

1. Plant in an area that receives at least partial sun, although this plant is shade-tolerant.
2. Use well-draining soil that won't become too saturated.
3. Water when the top layers of soil feel dry to the touch.
4. Feed with a fertilizer formulated for acid-loving plants.
   

Light

While this shrub will survive in a location with nearly full shade, flowering will be better in full sun to partial shade.

Soil

The ground should be kept evenly moist, but the soil should drain well. Japanese andromeda does not thrive in soggy soil.

Water

Japanese Andromeda has average water needs and does not tolerate drought well. Water if the first 3 inches of the soil feels dry.

Temperature and Humidity

This plant thrives in a moderate climate, where the temperatures don't get scorching hot. It tolerates a wide variety of humidity levels.

Fertilizer

Feed Japanese andromeda with a fertilizer meant for acid-loving shrubs. So if you are already fertilizing your azaleas, for example, you can use the same fertilizer for your Japanese andromeda. For the amount to use, and frequency of application, follow product label instructions.

Types of Japanese Andromeda

Beyond the species plant, cultivars have been developed that have become quite popular. The new spring leaves of even the species plant have a reddish-bronze color, but, on a number of the cultivars, these same leaves offer a more striking red color. Notable cultivars include:

• 'Compacta': This is a good choice if you need a shorter plant, as its mature height is just 4 feet.
• 'Forest Flame': New spring leaves start out an intense red, then fade to a pink that is still quite attractive.
• 'Mountain Fire': Orange mixes with the red on the young leaves of this cultivar.
• 'Red Mill': This is one of the best cultivars if you seek bright red color on the new foliage.
• 'Valley Rose': Grow 'Valley Rose' if you want a Japanese andromeda that bears light pink flowers.
• 'Variegata': One of the cultivars with two-toned leaves, the foliage of 'Variegata' is green in the middle, but the edge of the leaf is white.

Pruning

This plant has a naturally attractive shape and will often grow neatly with no pruning. However, cut off dead, dying, or diseased branches, and tidy up the foliage occasionally.

Propagating Japanese Andromeda

Though Japanese andromeda can be grown from seed, it takes a long time for the seeds to germinate and grow. Therefore, most choose to propagate the plant from cuttings:

1. Wait until the end of summer to cut a 6-inch stem of new growth from the original plant.
2. Remove the leaves, keeping only one or two pairs at the top of the stem.
3. Dip the end of the cutting in rooting hormone and place it immediately in a prepared container. Keep the cutting in indirect sunlight and ensure the soil stays moist, but not wet.
4. Let the roots grow until the following spring when the plants should be ready to transplant outside.

Potting and Repotting Japanese Andromeda

When planting Japanese andromeda in a pot, select one about the same size as the nursery pot it came in and make sure it has large drain holes, as Japanese andromeda does not like wet soil.

Fill the pot with well-draining potting mix and tamp the soil down around it with your hand to remove any trapped air. Water the plant immediately afterwards.

When the root system has filled the pot (an indicator is when water rushes right through the pot, or you see roots growing out of the drain holes), it is time to transplant it to a larger pot, one size up. Do this in the spring or fall and work some compost into the fresh potting mix.

Overwintering

Japanese andromeda is winter hardy to USDA zone 5 and needs no winter protection when grown in garden soil but the roots of container plants should be protected from cold, drying winter winds by wrapping burlap and a layer of bubble wrap around the container, or by placing it in an insulating silo.

Common Pests and Plant Diseases

Fungal diseases are a common plague for Japanese andromeda. To avoid this, ensure good air circulation around the plant and use a fungicide when appropriate.

The andromeda lacebug often attacks this particular plant, hence the name. To prevent it, keep your plant in full sun, apply horticultural oil to the undersides of the leaves, and use pesticides if necessary.

How to Get Japanese Andromeda to Bloom

Japanese Andromeda is highly regarded for its blooms. It is commonly used in foundation plantings, as a spring specimen, and in shrub borders. This shrub is highly valued by gardeners anxious to have color in the yard as soon as spring arrives.

Bloom Months

Japanse Andromeda's blooms may come in late winter or early spring, sometimes while there is still snow on the ground. They most commonly bloom during the month of April.

How Long Does Japanese Andromeda Bloom?

These flowers can last up to three weeks if the plant is cared for properly.

What Do Japanse Andromeda Flowers Look and Smell Like?

These showy flowers have coppery red leaves and inverted urn-shaped flowers that are white and fragrant. Blooms are each 1/4 inch long.

How to Encourage More Blooms

While the plant tolerates partial shade, too much shade is detrimental to its blooming ability. Make sure you have plenty of sunlight.

Caring for Japanese Andromeda After it Blooms

Once your plant is finished flowering, you can prune them back so they can set their buds for the following year during the summer.

Deadheading Japanese Andromeda Flowers

Deadheading the spent blooms is a good idea to encourage more flowering.

Common Problems with Japanese Andromeda

Japanese Andromeda is classified as a high-maintenance plant due to its susceptibility to numerous problems.

Leaves Wilting

The wilting of Andromeda’s leaves is commonly caused by Phytophthora root rot. The roots of the plant will eventually become brittle and brown. To prevent this, do not overwater the plant. Soggy soil that never dries out is the primary cause of root rot.

Leaves Yellowing and Browning

If the leaves are changing to yellow and then brown, your shrub is suffering chlorosis. Root rot is more than likely the culprit so check the moisture content of your soil. Roots that are compacted will take longer to dry out and cause the leaves to discolor. Nutrient deficiency could also result in foliage discoloration so make sure you are feeding your plant appropriately.

Branches Dying Back

This could indicate the growth of a fungal disease such as canker. Avoid periods of drought or low temperatures to prevent the onset of canker disease. Prune any infected branches as quickly as possible and use a fungicide if necessary.

From: thespruce