How to Grow Kalmia Polifolia - Plant Care & Tips

By NorwichGardener Team   /   2024

Kalmia polifolia is a flowering plant in the heath family. It is native to North America, where it is found in the eastern United States and Canada. The plant is a low-growing evergreen shrub that typically reaches heights of 1-2 m (3-6 ft). The leaves are oblong-lanceolate and measure 2-8 cm (0.8-3.1 in) long. The flowers are white or pink and appear in terminal clusters. Kalmia polifolia is a popular ornamental plant and is used in landscaping and horticulture.

How to Grow Kalmia Polifolia - Plant Care & Tips

Also known as

  • Mountain laurel
  • Wild blueberry
  • Sheep laurel
  • Bog laurel
  • Ivy-leaved laurel

Things to Know

  • Kalmia polifolia is a flowering shrub in the heath family.
  • It is native to eastern North America, from Newfoundland to Minnesota, and south to Alabama and Georgia.
  • It is commonly known as mountain laurel, calico-bush, or spoonwood.
  • Kalmia polifolia is the state flower of Connecticut and Pennsylvania.
  • The plant grows to 5–15 feet (5–6 m) tall and 8–10 feet (4–0 m) wide.
  • The leaves are evergreen, alternate, simple, oblanceolate to obovate, 3–6 inches (6–12 cm) long and 1–5 inches (5–4 cm) wide, with a wavy margin.
  • The flowers are borne in clusters of 6–12, each flower 3/4–1 inch (9–5 cm) wide with five white petals and 10 stamens.
  • The fruit is a five-lobed capsule.
  • Kalmia polifolia is often grown as an ornamental plant.
  • It is also used in the production of mountain laurel brandy and honey.

Planting Process

  1. For kalmia polifolia, first step is to find a suitable location. This plant prefers partial to full sun, and well-drained soil.
  2. Amend the soil with organic matter such as compost or peat moss to help with drainage.
  3. Dig a hole twice the diameter and depth of the plant’s root ball.
  4. Place the plant in the hole, and backfill with soil.
  5. Water thoroughly to settle the roots.
  6. Mulch around the base of the plant to help with moisture retention.
  7. Fertilize in early spring with an all-purpose fertilizer.
  8. Deadhead spent flowers to encourage new blooms.
  9. Prune as needed to shape the plant.
  10. Kalmia polifolia is generally pest and disease free, but watch for scale, aphids, and powdery mildew.

Soil Condition

About soil conditions, Kalmia polifolia prefers moist to dry soils that are acidic. It grows best in full sun to partial shade, but can also tolerate full shade. The plant is also quite tolerant of drought and salt spray.

Light requirement

Similar to other members of the genus Kalmia, Kalmia polifolia requires full sun to partial shade for optimal growth. It will tolerant a wide range of soils as long as the soil is well-drained. This plant is also quite drought tolerant once it is established.

The Temperature

The temperature condition of kalmia polifolia is tropical. It grows best in temperatures that are warm and humid. It can tolerate some light frosts but will not survive prolonged periods of cold weather. Kalmia polifolia is native to the Caribbean and Central America but can be found in other parts of the world as well.

Humidity Requirement

Ideal humidity condition for this plant is 60-70%. If the humidity is too low, the leaves will turn brown and the flowers will fall off. If the humidity is too high, the leaves will start to yellow and the flowers will not open.

The Fertilizer

For the fertilizer, this type of plant prefers acidic soil, so a fertilizer with a low pH is best. You can also use organic matter such as compost or pine needles. As for the root, this plant has a taproot system, so it is best to plant it in a deep pot.

About light

Pruning kalmia polifolia is a necessary process to ensure its health and vitality. This evergreen shrub can grow up to 6 feet tall and wide, making it a significant focal point in the landscape. When pruning, focus on removing any dead, diseased, or damaged branches. Doing so will encourage new growth and help the plant to maintain its compact form. Also, prune away any branches that are crossing or rubbing against each other, as this can damage the bark. Finally, trim back any branches that are growing beyond the desired shape of the plant.

About Propagating

Propagation of Kalmia polifolia is typically done through seed, although rooting softwood or semi-ripe cuttings taken in late summer can also be successful. Seeds should be sown as soon as they are ripe in a cold frame or cold, moist stratification can be done for 3-4 months prior to sowing. Cuttings should be taken from new growth and rooted under high humidity with bottom heat.

Growth Speed

Usually, the plant growth rate is due to the presence of mycorrhizal fungi. Mycorrhizal fungi form a symbiotic relationship with the kalmia polifolia, providing the plant with essential nutrients and water while the plant provides the fungi with carbohydrates. This relationship is essential for the plant's growth and survival.

Common Problems

Common problems for this kind of plant are powdery mildew, leaf spots, and stem cankers. These problems are mostly due to too much moisture or humid conditions. To prevent these problems, make sure the plant has good drainage and does not stay too wet.

Tips on Growing

  • Make sure to plant your kalmia polifolia in an area with plenty of sunlight.
  • Choose a planting location that has well-drained soil.
  • Water your kalmia polifolia regularly, especially during the hotter months.
  • Add a layer of mulch around your kalmia polifolia to help retain moisture.
  • Fertilize your kalmia polifolia every few months with a balanced fertilizer.
  • Prune your kalmia polifolia regularly to encourage new growth and prevent leggy plants.
  • Keep an eye out for pests and diseases and treat accordingly.
  • Deadhead spent flowers to keep your plant looking tidy and to encourage more blooms.
  • Overwinter your kalmia polifolia indoors in a cool, bright location.
  • Enjoy the beautiful blooms of your kalmia polifolia all season long

Similar Plants

  • Kalmia macrophylla
  • Kalmia latifolia
  • Kalmia glauca
  • Kalmia cuneata
  • Kalmia procumbens
  • Kalmia refrigerata
  • Kalmia scopulorum
  • Kalmia heath
  • Kalmia panamintensis
  • Kalmiopsis leachiana

Kalmia polifolia information from the Global Compendium of …
Online Virtual Flora of Wisconsin - Kalmia polifolia
Kalmia polifolia Wang., 1906 July 2 | HOLLIS for

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Reviewed & Published by Richelle
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