Many of New England’s native plant species produce vibrant summer to fall flowers and will tolerate partial to full shade. Choose a monochromatic landscape design and focus on one colour for the garden, or incorporate multiple varieties and cultivars for a rainbow display of blossoms. Some non-native species, such as the gladiola, will add vibrant colour to the garden and winter well in New England soil.
Mountain Laurel (Kalmia Latifolia)
Mountain laurel is native to North America and is hardy to zone four. Traditionally, Mountain laurel grew at the edge of forests or bodies of water in filtered light. The plant will grow between 5 and 12 feet tall and about as wide as it is tall. Considered an evergreen, mountain laurel will add year-round colour to the garden in addition to the flowers produced from late May to early June. Blossoms vary and could include pink, white, red and banded varieties. The Bridesmaid variety produces dark pink buds that open into a bi-coloured pink and white flower. Flowers grow in clusters of approximately 4 to 6 inches. Plant in partial shade with some protection from the elements. Acidic moist soil will produce the best flowers.
Oakleaf Hydrangea (Hydrangea quercifolia)
Oakleaf hydrangea is a flowering shrub that is hardy to zone five. Oakleaf hydrangea’s dark green leaves form a rounded shape with an average height between 4 and 8 feet. Generally, oakleaf hydrangea will grow wider than it does tall. Oakleaf hydrangea blossoms add a dynamic element to the garden as the blossoms will transition in colour throughout the season. Flowers form as upright pyramidal clusters up to 10 inches long. Blooms begin as snowy white bunches that turn pinkish-white in late summer and eventually transform into a tan cluster in autumn. Peak bloom for oakleaf hydrangeas is early July. Plant in full to partial shade. Use as a colourful border in the garden.
Rosebay Rhododendron (Rhododendron maximum)
Rosebay rhododendron is a large evergreen shrub that is hardy to zone four. Typically rosebay will grow between 8 and 15 feet tall but has been known to reach 30 feet in some locations. Rosebay rhododendron peaks in late June with a vivid display of rose-pink to pink-white blossoms. Flowers are 1.5 inches across and grow in clusters of up to 25 flowers, which makes for a showy and colourful display. Plant in partial to dense shade in well-drained acidic soil. Use as a border or near the edge of wooded areas to add colour and visual interest.
Gladiolus (Gladiolus "Vandohla")
Gladioli originated in South Africa, and growers have crossbred and cultivated them for over 250 years. Today, gardeners can find nearly any colour or hue of gladiolus to add a dramatic and colourful touch to a New England garden, including yellow, red, purple, orange and dusty rose shades. Although gladioli prefer full sun, they will tolerate partial shade and produce abundant flowers. Bulbs will winter over, though it may be necessary to add some insulation to the flower bed by covering in mulch before the first frost. Gardeners can treat gladioli as annuals in the New England garden or dig them up at the close of each season and winter them indoors. Store bulbs indoors at a temperature between 1.67 and 7.22 degrees Celsius. Gladioli will typically grow between 2 and 5 feet tall.