Friday, December 29, 2006

Growing Perennials in the USA


Herbaceous perennials generally survive well for three or more growing seasons, with the tops usually dying back to the ground in the autumn. The plant's crown and roots resume new growth in the next spring season. A few perennials are evergreen, retaining a green rosette of leaves at the base of the plant during the winter.

Hardy perennials can live through the winter without protection. Many plants like cannas and dahlias are hardy perennials in South Carolina and elsewhere in the south, and will not live through the winter outdoors farther to the north. On the other hand, many of the perennials that grow well in the Northeast United States or England will not tolerate hot, humid summers. Since books about perennials are often written for cooler climates, it is important to good information in selecting plants that are adapted specifically to Southern heat and humidity. Check with your garden store to be sure about your selections.

Perennials provide color and decor for your landscape all year with endless variations in colors, sizes, and blooming times. Although some perennials flower for only a few weeks at a time, the changing displays form excitement of variation for your perennial garden. Many perennials will bloom again in the warm climate of the south. Some perennials, such as ferns and hostas, are grown specifically for their beautiful foliage. Foliage plants lengthen the season for color and texture in gardening.


While the traditional English perennial plant border was entirely herbaceous perennials, they can be attractively used with other plants in the total landscape for variety of color and texture. Perennials are good ground covers, mixed with annuals, grown in containers, and
used to accent garden areas. There are perennials groomed for full sun or heavy shade, and for almost any type of soil. You should select perennials suited to the inherent growing conditions of their planting space. Select a planting area with good air circulation and good drainage.


Good soil preparation is vital to perennials, since they may be in place for several years. Deeply spade the beds to a depth of 8 to 10 inches. Enhance clay soils by mixing in at least 2 inches of pine bark humus, compost, leaf mold, or small pea gravel in well to improve drainage and aeration. Improve water retention in sandy soils by mixing in 2 to 3 inches of pine bark humus, composted leaf mold, or peat moss. Good soil drainage is essential to the success of most perennials and raised flowerbeds will ensure adequate drainage.

Base your fertilizer and lime applications on the results of a good soil test. In the absence of a soil test, add a complete fertilizer such as 10-10-10 at the rate of 1 pound per 100 square feet of flowerbed area or a complete slow release fertilizer, following the label directions.
A pH of 6.0 to 6.5 is goods. Most southern soils are acidic and require the addition of lime to correct pH. Check your soils with a soil test in the north. Incorporate lime and fertilizer, as needed, into the top 4 to 6 inches of soil after mixing in the soil boosters. Then rake the soil surface until smooth.

Most perennials are planted in the autumn or early spring. Fall planting gives the plant more time to establish itself before the start of active spring growth. Perennials planted in the fall are well established before hot weather. Fall planting should be finished at least 6 weeks before hard-freezing weather occurs. Early spring, after soils is well thawed, is a good time to plant perennials. Many perennials grow from seed, but many gardeners prefer to established plants. Perennials are available grown in containers, field-grown, or shipped with bare roots and still dormant.

If plants are somewhat pot bound at planting time, loosen the roots around the bottom and sides of the root ball and spread them out in the bottom of the planting hole. To encourage side root growth, make the hole twice as wide as it is deep. Place the plant, fill the hole, firming the soil in around the plant to remove air pockets. Be sure the crown of the plant is flush with the soil surface.

Water plants by allowing them to settle first after planting. Pay attention to watering the first few weeks while plants develop root systems and become established. Adequate moisture is essential for perennials. Most perennials require at least 1 to 1 1/2 inches of water weekly from rain or irrigation. More is needed during hot weather. To promote deep root growth, water thoroughly and allow the soil surface to dry before watering again. Soaker hoses and drip irrigation are ideal. They save water and avoid soaking leaves and flowers. To retain moisture, mulch with a 1- to 2-inch layer of compost, pine bark or pine straw; and avoid heavy mulching.

Weed control should be done by hand. Follow label directions before using any herbicides. Fertilization should be based on the results of a soil test. In the absence of a soil test, apply a complete fertilizer such as 8-8-8 or 10-10-10 at the rate of 1 to 2 pounds per 100 square feet of bed area just before new shoots emerge in the early spring. Avoid touching emerging leaves with fertilizer to avoid damage. Several types of perennials will not bloom the first year; and a few, such as peonies, take several years to bloom fully.

Many perennials need to be staked to prevent them from bending during wind and rain. When staking is done correctly, the plants grow to cover the stakes. Remove old flowers to encourage rebloom on perennials. Many perennials must be cut back to ground level after bloom is finished to encourage new leaf growth from the base. Remove dead foliage and stems in the fall, and mulch to protect crowns and roots from mild and freezing weather variations.

Most perennials become overcrowded and require division and thinning. Many perennials are easily propagated in this way. Other methods of propagating perennials include stem cuttings, root cuttings, and seeding.

Many perennials are available in several different cultivars of various colors, heights, blooms timings, and blooming potentials form small to large flowers. For example, heat resistant and humidity tolerant cultivars like lambs ears are better suited to southern climates in the US than to the northern states. Be sure to consult with a local garden center in your community for perennial cultivars that are especially suited to your region, according to soil type, weather, seasons, and other natural considerations.

Below are listed several of the perennial plants that are useful for special purposes. Your experience with the plants may vary somewhat across the USA. Of course, this list is not all inclusive, but does include plants that should work well. Use it as a guide and then experiment a little. The Latin name and a common name are given for most of these following perennial listings. Check with your garden center on your final selections in order to gather more information and planting guidelines.

Perennials Successful in Sunny, Dry Areas
Achilles Achillea or Yarrow
Anthemis tinctoria Golden Marguerite
Arabis caucasica Rock Cress
Armeria maritime Common or Sea Thrift
Artemisia Artemesia
Asclepias tuberosa Butterfly Weed
Catananche caerulea Cupid's Dart
Coreopsis Coreopsis
Echinops ritro Small Globe Thistle
Euphorbia Spurge
Gaillardia Blanket Flower
Helianthus x multiflorus Perennial Sunflower
Hemerocallis hybrids Daylily
Lavandula angustifolia English Lavender
Liatris Gayfeather
Malva alcea Hollyhock Mallow
Oenothera Sundrops
Opuntia humifusa Prickly Pear Cactus
Perovskia atriplicifolia Russian Sage
Polygonum cuspidatum var. compactum Fleeceflower
Rudbeckia Blackeyed Susan
Sedum Autumn Joy, Showy Stonecrop, Live Forever
Sempervivum tectorum Hens and Chickens
Stachys byzantina Lamb's Ear
Yucca filimentosa Yucca

Perennials Successful in Poor or Sandy Soils
Achillea species Yarrow
Anthemis tinctoria Golden Marguerite
Asclepias tuberosa Butterfly Weed
Baptisia species Wild Indigo
Belamcanda chinensis Blackberry Lily
Euphorbia species Spurge
Gaillardia species Blanket Flower
Gaura lindheimerii Gaura
Hemerocallis species Daylily
Hesperaloe parviflora False Red Yucca
Lantana species Lantana
Plumbago auriculata Plumbago
Salvia greggi Texas Sage
Setcrasea pallida Purple Heart
Yucca species Yucca

Perennials Successful in Moist to Wet Areas
Aruncus dioicus Goat's Beard
Astilbe x arendsii Astilbe
Campanula glomerata Clustered Bellflower
Cimicifuga racemosa Black Snakeroot
Dicentra Bleeding Heart
Houttuynia cordata Variegata, Houttuynia
Iris ensata Japanese Iris
Ligularia Ligularia
Lobelia cardinalis Cardinal Flower
Lysimachia clethroides Gooseneck Loosestrife
Lysimachia punctata Yellow Loosestrife
Matteuccia pensylvanica Ostrich fern
Physostegia virginiana Obedient Plant
Rodgersia pinnata Featherleaf, Rodgersflower
Tradescantia x andersoniana Virginia Spiderwort
Trollis europaeus Globeflower

Perennials Successful in Full Shade
Ajuga reptans Bugleweed
Arum italicum Pictum, Painted Arum
Asarum Wild Gingers
Convallaria majalis Lily of the Valley
Dodecatheon media Common Shooting Star
Galium odoratum Sweet Woodruff
Helleborus orientalis Lenten Rose
Hosta Hosta
Lamium maculatum Spotted Deadnettle
Liriope spicata Creeping Lilyturf
Mertensia virginica Virginia Bluebells
Osmunda regalis Royal Fern
Polygonatum biflorum Small Solomon's Seal
Polygonatum commutatum Great Solomon's Seal
Pulmonaria angustifolia Blue Lungwort
Pulmonaria saccharata Bethlehem Sage
Tiarella cordifolia Foam Flower
Tradescantia x andersoniana Virginia Spiderwort
Viola odorata Sweet Violet

Perennials Successful in Partial ShadeAlchemilla mollis Lady's Mantle
Anemone x hybrida Japanese Anemone
Aquilegia Columbine
Astilbe Astilbe
Bergenia cordifolia Heartleaf Bergenia
Brunnera macrophylla Siberian Bugloss
Ceratostigma plumbaginoides Plumbago
Dicentra Bleeding Heart
Doronicum cordatum Leopardsbane
Geranium Cranesbill, Hardy Geranium
Heuchera sanguinea Coralbells
Myosotis sylvatica Garden Forgetmenot
Tricyrtis hirta Toadlily

Perennials Good for a Long Blooming Season
Achillea Moonshine Yarrow
Asclepias tuberose Butterfly Weed
Coreopsis lanceolata Coreopsis
Coreopsis verticillata Moonbeam
Dicentra eximia Fringed Bleeding Heart
Echinacea purpurea Purple Coneflower
Gaillardia x grandiflora Blanket Flower
Rudbeckia fulgida Goldsturm Blackeyed Susan
Salvia x superba Perennial Salvia
Scabiosa Pincushion Flower
Sedum Autumn Joy, Showy Stonecrop, Live-Forever
Veronica spicata Sunny Border Blue, Spike Speedwell

Perennials that Produce Fragrant FlowersArabis caucasica Rock Cress
Convallaria majalis Lily of the Valley
Dianthus plumarius Cottage Pinks
Dictamnus albus Gas Plant
Hosta plantaginea Fragrant Plantain Lily
Iris hybrids Iris
Lavandula angustifolia English Lavender
Paeonia lactiflora Peony
Viola odorata Sweet Violet

Perennials that Produce Flowers Good for CuttingAchillea Achillea or Yarrow
Aconitum napellus Garden Monkshood
Alchemilla mollis Lady's Mantle
Anemone x hybrida Japanese Anemone
Aquilegia Columbine
Armeria maritima Common or Sea Thrift
Astrantia major Great Masterwort
Campanula persicifolia Peachleaf Bellflower
Chrysanthemum x superbum Shasta Daisy
Convallaria majalus Lily of the Valley
Coreopsis Coreopsis
Delphinium elatum Delphinium or Larkspur
Dicentra Bleeding Heart
Echinacea purpurea Purple Coneflower
Echinops ritro Small Globe Thistle
Gaillardia Blanket Flower
Gypsophilia paniculata Baby's Breath
Heliopsis helianthoides Sunflower Heliopsis
Heuchera sanguinea Coralbells
Lavandula angustifolia English Lavender
Liatris Gayfeather
Lilium Hardy Lilies
Lupinus Russel Hybrid Lupine
Paeonia hybrids Peony
Penstemon Beardtongue
Platycodon grandiflorus Balloon Flower
Rudbeckia Blackeyed Susan
Scabiosa Pincushion Flower
Stokesia laevis Stokes Aster
Veronica spicata Spike Speedwell

Perennials Ideal for Dried Flower or Fruit ArrangementsAchillea Achillea or Yarrow
Alchemilla mollis Lady's Mantle
Asclepias tuberose Butterfly Weed
Baptisia australis False Indigo
Catananche caerulea Cupid's Dart
Echinops ritro Small Globe Thistle
Gypsophilia paniculata Baby's Breath
Iris siberica Siberian Iris and its seed pod
Lavandula angustifolia English Lavender
Liatris Gayfeather
Limonium latifolium Statice
Papaver orientale Oriental Poppy and its seed pod
Physalis alkekengi Chinese Lantern and its seed pod
Scabiosa Pincushion Flower

Perennials that Attract ButterfliesAchillea Achillea or Yarrow
Armeria maritime Common or Sea Thrift
Aruncus dioicus Goat's Beard
Asclepias tuberose Butterfly Weed
Aubrieta deltoidea False Rock Cress
Chrysanthemum Mums
Coreopsis Coreopsis
Dictamnus albus Gas Plant
Echinacea purpurea Purple Coneflower
Gaillardia Blanket Flower
Lavandula angustifolia English Lavender
Liatris Gayfeather
Monarda didyma Bee Balm
Phlox paniculata Summer Phlox
Rudbeckia Blackeyed Susan
Sedum Autumn Joy, Showy Stonecrop, Live-Forever

Perennials that Attract to Hummingbirds
Alcea rosea Hollyhock
Aquilega Columbine
Asclepias tuberose Butterfly Weed
Dianthus Cottage Pinks
Dicentra Bleeding Heart
Digitalis Foxglove
Hemerocallis Daylily
Heuchera sanguinea Coralbells
Lobelia cardinalis Cardinal Flower
Monarda didyma Bee Balm
Penstemon Beardtongue

Perennials that Attract Other BirdsActea, or Baneberry: Actea rubra with red berries and Actea spicata with white berries
Ligularia clivorum
Perennial grasses, genus Panicum: Panicum virgatum

Perennials That Can Be InvasiveAegopodium podagraria Goutweed
Ajuga Bugleweed
Artemisia ludoviciana Western Mugwort
Arundinaria Bamboo
Arundo donax Giant Reed
Bambusa species Clumping Bamboo
Campanula rapunculoides Creeping Bellflower
Chrysanthemum leucanthemum Oxeye Daisy
Coronilla varia Crown Vetch
Cortaderia jubata Purple Pampas Grass
Equisetum hyemale Horsetail
Euphorbia cyparissias Cypress Spurge
Elymus arenarius Blue Lyme Grass
Eupatorium coelestinum Hardy Ageratum
Hemerocallis fulva Common Daylily, Ditch Lily
Houttuynia cordata Chameleon Plant
Imperata cylindrica Japanese Blood Grass
Iris pseudocorus Yellow Iris
Lantana camara Lantana
Lychnis coronaria Rose Campion
Lysimachia Loosestrife
Lythrum salicaria Purple Loosestrife
Miscanthus sinensis Silver Grass, Zebra Grass
Macleaya Plume Poppy
Mentha Mint
Oenothera Evening Primrose
Persicaria virginiana Tovara
Phalaris arundinaceae Ribbon Grass
Phyllostachys Japanese Bamboo
Physostegia virginiana Obedient Plant
Polygonum Knotweed
Tanacetum vulgare Tansy
Vernonia Ironweed


Peter watson said...

Other things to consider with regard to the followers blades include their size and message

Angel17 said...

So useful! Thanks for sharing those tips.