I must confess - I have this thing for purple-leaved plants. As options for purple foliage plants have expanded over the years, my love for them has only grown. Adding a purple tree, shrub, perennial, annual, or even an herb or vegetable to the landscape is sure to stand out against the green leaved plants in the landscape. If you think you might like adding a few purple foliage plants to your landscape, below are several that perform well in Iowa.
Trees
'Crimson King', 'Royal Red', and 'Crimson Sentry' are popular Norway maple (Acer platanoides) cultivars with purple foliage. The purple leaved cultivars grow rather slowly, but may eventually reach a height of 40-60 feet. All Norway maples may reseed and become invasive in nearby natural areas.
Crabapples, such as 'Orange Crush', 'Prairiefire', 'Purple Prince', and Royal Raindrops™ are small, ornamental trees. Their purplish new growth makes them stand out in the landscape. In addition to their colorful foliage, crabapples have attractive flowers in spring and showy fruit in fall. Crabapples vary in habit, and they range in mature height from 12 to 25 feet. Many possess good disease resistance.
Purple Beech (Fagus sylvatica cultivars) and Purple-leaf Japanese Maples (Acer palmatum or A. japonicum cultivars) complete my list of woody plants with purple foliage for Iowa. All of these are excellent, slow-growing trees in the landscape. These small trees are more site-specific than the other trees mentioned, requiring a protected site in partial shade and moist, fertile soils that are well drained. They are also expensive and not reliably hardy for northern Iowa.
Shrubs
Prized for its white to pale pink spring flowers and reddish purple foliage, purple sandcherry (Prunus x cisterna) was widely plant in past years. Unfortunately, purple sandcherry often experiences dieback and is often short-lived. Red filbert (Corylus maxima 'Atropurpurea') and smokebush (Continus coggygria) are great alternatives to sand cherry. The red filbert grows from 8-12 feet tall and produces an edible nut. Smokebush is a 10- to 15-foot-tall, multi-stemmed shrub with feathery, smoke-like "flowers" in summer. Cultivars like 'Royal Purple' and 'Velvet Cloak' command attention in and out of bloom. In harsh winters Smokebush may die back to the ground only to recover the following summer with 5 feet of new growth.
Elderberry (Sambucus nigra) is 5- to 8-foot tall shrub with edible purple-black fruit. Several cultivars of elderberry, such as Black Beauty™ or Black Lace™, are noted for their purple foliage. Plants prefer partial shade, and moist, well-drained soils. Plants may spread by root suckers.
For adaptable, hard-to-kill shrubs with purple foliage consider ninebark (Physocarpus opulifolius), weigela (Weigela florida), or barberry (Berberis thunbergii f. atropurpurea). Ninebark cultivars such as 'Diablo', Little Devil™, and Summer Wine™ have clusters of flat-topped pinkish white flowers in spring followed by dark burgundy-purple leaves during the summer. Cultivars range in height from 3 to 10 feet tall. Ninebark is also noted for its attractive exfoliating bark in winter. Weigela cultivars like Wine and Roses™, Midnight Wine™, Fine Wine™, or 'Dark Horse' are noted for their showy pink flowers in spring and purple foliage in summer. Plants typically grow from 2 to10 feet tall in Iowa landscapes. Barberry cultivars like 'Crimson Pygmy', 'Helmond Pillar', 'Rosy Glow', 'Royal Cloak', and Royal Burgundy™ add both color and thorns to the landscape. Barberries range in height from 2 to 6 feet tall.
Perennials
Wonderful perennials with burgundy to purple foliage include: 'Chocolate' Joe-Pye weed (Eupatorium), 'Chameleon' spurge (Euphorbia dulcis), and several cultivars of snakeroot (Actaea racemosa) and red-leaf rose mallows (Hibiscus hybrids). 'Chocolate' Joe-Pye Weed and the black snakeroots have white blooms in late summer or fall. Both prefer partial shade and moist soils. 'Chocolate' Joe-Pye Weed grows 3 feet tall. 'Brunette', 'Atropurpurea', 'Hillside Black Beauty', 'Black Negligee' or 'Chocoholic' are highly prized burgundy-black leaved cultivars of snakeroot that grow 3 to 6 feet tall. 'Chameleon' Spurge is a rounded plant that reaches 12 to 18 inches tall and performs best in full sun. It produces yellow-green flowers in spring and tends to reseed. Rose mallows with purple foliage include 'Kopper King', 'Mahogany Splendor', 'Midnight Marvel', and 'Red Shield'. Rose mallows are also noted for their attractive pink, red, or white flowers in summer. Plants prefer full sun with moist soils and range in height from 3 to 8 feet.
For something smaller in size, there are hundreds of red, burgundy, purple to almost black foliage cultivars of Coral Bells (Heuchera hybrids) available to home gardeners. 'Palace Purple', 'Dark Secret', 'Pewter Veil', 'Frosted Violet', 'Obsidian', and 'Plum Pudding' are just a few with variations of purple, silver, and undulating leaf edges readily available for Iowa landscapes. Coral bells prefer partial shade and well-drained soils and range in heights from 6 to 20 inches.
Groundcovers with burgundy to purple foliage include 'Chocolate Chip' and 'Black Scallop' bugleweed (Ajuga reptans), 'Morchen' and 'Vera Jameson' stonecrop (Sedum species and hybrids), and red to burgundy forms of hens-and-chicks (Sempervivum). Tender perennials such as 'Australia' and 'Red Futurity' Canna, 'Black Magic' and 'Black Beauty' Colocasia, and 'Bishop of Llandaff' Dahlias are also noted for their dark foliage.
Annuals
Castor Beans (Ricinus communis) and Joseph's Coat (Amaranthus tricolor) are the largest (5 to 10 feet tall in Iowa gardens) of the annuals with purple foliage cultivars worthy of mention. Look for 'New Zealand Purple' or 'Red Spire' for dark foliage colors of castor bean. However, beware of castor bean as all parts are poisonous (when eaten) to people and pets. Joseph's coat cultivars like 'Illumination' and 'Molton Fire' have showy burgundy-purple to pink-purple leaves. Plant may reach a height of 4-6 feet when planted in fertile, moist, well-drained soils.
Coleus and some ornamental grasses add interest to containers and annual plantings in the landscape. There are numberous cultivars of coleus with purple, red, burgundy, or even almost black foliage. Some cultivars that may be available at local garden centers include 'Black Prince', 'Wizard Chocolate', and ColorBlaze Marooned™. The linear leaves of ornamental grasses, such as purple fountain grass (Pennisetum sectaceum 'Rubrum') or New Zealand flax (Phormium tenax) provide texture and contrast with the more rounded leaves of other plants.
For a more groundcover or trailing type habit, consider sweet potato vine (Ipomoea batatas) or calico plant (Alternanthera dentata). Purple foliage forms of the trailing sweet potato vine include 'Blackie', 'Blackberry Heart', or 'Midnight Lace'. 'Purple Knight' is a popular burgundy-purple foliage form of the calico plant.
Persian shield (Stobilanthes dyerianus) and wandering jew (Tradescantia pallida) are commonly grown as houseplants, but they too could be used in containers for their attractive purple foliage. 'Purple Heart' or 'Purple Queen' are two readily available cultivars of the trailing jew.
Herbs and vegetables
There are also a few herbs and vegetables with purple foliage, like 'Purple
Ruffles' or 'Red Rubin' Basil, Purple leaf garden sage (Salvia officinalis 'Atropurpurea'), 'Bulls' Blood' Beet, 'Black Pearl' ornamental pepper, and 'Redbor' Kale. These attractive and edible plants make great additions to vegetable gardens, containers, and even sunny spots in the landscape.
Consider planting a few of these colorful foliage plants to add a little purple passion to your landscape.
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