Mountain laurel abounds across state
Our state flower is the mountain laurel (Kalmia latifolia), a magnificent, broadleaved, evergreen shrub whose delicate flowers and strong branches represent the beauty and strength of our Commonwealth.
In 1933, Pennsylvania Gov. Gifford Pinchot declared mountain laurel the state flower of the Commonwealth, his choices being the mountain laurel and pink azalea. The presence of mountain laurel in almost all of Pennsylvania's 67 counties was one reason for its selection.
Mountain laurel is a member of the Ericaceae or heath family, which also includes rhododendrons, azaleas, huckleberries, blueberries, cranberries and Indian pipe.
This shrub is native to the eastern United States, its habitat ranging from southern Maine to northern Florida and west to Indiana and Louisiana in USDA zones 5 to 9.
There are seven species of mountain laurel found in the United States, with two varieties of Kalmia latifolia native to Pennsylvania: sheep laurel (K. angustifolia) and bog laurel (K. polifolia).
Sheep laurel flowers in June and July in woodlands of the eastern third of the Commonwealth.Bog laurel is limited to sphagnum bogs. While a rare inhabitant of the northeastern corner of Pennsylvania, it is more common in the New England states and across Canada.In its natural habitat, mountain laurel grows slowly, averaging 4 to 8 feet over a decade. Mature plants average heights from 7 to 10 feet, resembling a small tree.The laurel's ascending and horizontal branches often are contorted, and the laurel's wood and burls have been used for various tools and utensils, explaining one of its many monikers, “spoonwood.”Mountain laurel has been cultivated by commercial growers for many years. Nurseries and growers sell both cultivars and native specimens. Mountain laurel grows best in dappled sunlight but it does tolerate full sun and part shade.If rhododendron and azaleas are growing well in the area in which mountain laurel is to be planted, the mountain laurel will grow well, too. Mountain laurel prefers moist, well-drained acidic soil.The clay soil of Butler County will not help mountain laurel to thrive unless the soil is amended appropriately with organic material.Purchase mountain laurel shrubs that are healthy in appearance, with or without blooms. Assure that the stems are strong and the leaves have turgor and are not dry or brittle.Plant mountain laurel in the same manner as other shrubs. Dig a hole as deep as the root ball and three times its width. Add compost to the fill dirt to amend the soil. Place mulch, pine needles or shredded bark to retain moisture. Mountain laurel plants do not require much fertilizer, so situate them away from lawns that are maintained with high nitrogen fertilizers.Mountain laurel shrubs have a shallow root system, thus requiring frequent watering. Apply two inches of water each week for the first season when planted.Mountain laurel forms buds for next year's flowers soon after this season's flowers fade. Prune mountain laurel after flowering to avoid cutting away the new buds. Prune faded flowers after blooming to allow the shrub to focus on growth instead of seed development.While the mountain laurel is a native shrub, it is one that comes with a certain respect. All parts of the mountain laurel plant are poisonous. The highest concentration of poison is in the young shoots and new leaves. Animals that eat too much mountain laurel can become ill. Honeybees who collect flower pollen and nectar can produce honey that has some degree of poison in it as well. However, the dilution of mountain laurel pollen and nectar with other pollen and nectar sources should not cause problems.Mountain laurel blooms in late May to mid-June and into July throughout Pennsylvania.To honor the mountain laurel, many activities occur throughout the Commonwealth. From June 12-20, the Pennsylvania State Laurel Festival is held in Wellsboro (https://festivalnet.com/217/Wellsboro-Pennsylvania/Festivals/Pennsylvania-State-Laurel-Festival). The Brookville Laurel Festival will be held June 12-20 in Brookville (https://visitpago.com/events/brookville-laurel-festival/).Penn State Extension (https://extension.psu.edu/mountain-laurel) offers detained information about how mountain laurel flowers propel their pollen to propagate their species.If you have questions about mountain laurel and other gardening practices, call the Butler County Master Gardener Garden Hotline at 724-287 4761, ext. 7 or email the Master Gardeners at butlermg@psu.edu.<i>Lisa Marie Bernardo, Ph.D., RN, is a Penn State Master Gardener of Butler County.</i>
