Perennials are the backbone of a garden

Martie Young
Adams County Master Gardener

Once you have planted a perennial you know that plant will bloom in the same spot for at least several years and maybe a lot more. You also (sometimes optimistically) think you have done all the work you need to do once you have planned and planted a perennial garden. Of course there will be weeding, but if the perennial grows well, it may shade out all the weeds; you will have to water but only until the plant is well established; you will probably have to divide the plants, but if you choose your plants well maybe you won't have to divide for several years. Have I talked you into trying perennials yet? 

If you don't have perennials yet, late summer and fall is the time to plan. Pick your location, then prepare the soil. If you are starting a new bed that has turf grass growing there, an easy way to prepare the bed is to outline your bed, cover the spot with lots of black and white newsprint and cover the newsprint with soil, compost, or mulch. By late fall you can dig into the soil. You will find that the grass has been killed and the newsprint is decomposing. If you dig your bed in the fall, you will be able to plant in early spring with very little extra effort. Remember to wait until the soil has dried sufficiently that you do not end up with clumps of mud. The soil should crumble when you squeeze a handful.

During the fall and winter you can read the garden catalogs and magazines and choose the perennials you want to buy. Perennials should be planted before annuals; they will not be as affected by sudden cold nights; you do not have to wait for Mother's Day to start playing in your garden!

To get you started, come to the Trial Garden located at the Ag Building in Gettysburg. The Master Gardeners have annuals and perennials to show you. Since perennials usually bloom for a specified period, you may not have paid them much attention. Some bloom only in spring, others in early summer and others in the fall. Try to choose perennials for yourself that have a long bloom season. Do this by observing what is blooming now, this summer and fall, and decide if it's something you want. Ask questions about the maintenance involved and whether the plant grows in sun or shade.

Penn State has provided the Master Gardeners with several perennials to be evaluated over a period of years. The perennials in our garden have been planted for approximately three to five years and are now mature plants. They are good examples of plants that grow in full sun, and one that is doing well even though it is recommended to grow with some shade (Campanuala 'Chettle Charm'). These perennials have been evaluated in over 40 display gardens managed by Master Gardeners across the state.

The perennials are listed below along with two woody shrubs that we also evaluate.

Rudbeckia ‘Goldsturm’

Bright, bold, and easy to grow! Blooms nearly all summer! Rudbeckia fulgida ‘Goldsturm’ the 1999 Perennial Plant Association’s Plant of the Year -a simply magnificent hardy perennial for any full sun to partially shady area. Once established, plants are virtually maintenance free. Bright golden-yellow petals surround dark brown centers. Plants grow 18 to 24" tall and should be spaced 2-3’ apart in beds, borders or meadow areas. Prolific bloomers, plants produce ample flowers to grace both the garden as well as fresh arrangements from July through September. Hardy in zones 3-8. ‘Goldsturm’ is a long-blooming, long-lived perennial. It tolerates clay soils and mild droughts, but grows best in well-drained, consistently moist soil. Plant bare-root or container-grown plants anytime during the growing season. When establishing a new planting, mulch to retain moisture.

Coreopsis Rosea ‘Sweet Dreams’

Sparkling white petals with pinkish red centers are refreshingly different for a coreopsis. And, these compact, mounding plants form a rapidly spreading, deer-resistant groundcover that are drenched in the uncommon blossoms. Cut them back when flowering ends, and you’ll be rewarded with a second flush as autumn leaves begin to fall. A good companion for blue or yellow perennials and an appealing cut flower. 1 3/4" to 2" blooms-- late spring to midsummer and fall when sheared grows to 18 to 24" tall. It has no serious insect or disease problems. Root rot may occur in heavy, poorly-drained soil. Performs best in cool summer climates and can appear rather scraggly with poor flowering in the hot and humid summer conditions of the deep South. Weak plant stems do sprawl and mat.

Coreopsis Verticillata ‘Moonbeam’

The pale yellow flowers are borne in profusion all summer above needlelike foliage and blend well with practically every color. ‘Moonbeam’ makes a superb front-of-the-border plant but can also light up a foundation planting. Blooms June-October and grows to 18 to 24" tall. It will grow in full sun or light shade in well-drained soil. Bare root plants are best planted in spring; potted plants can be planted anytime from late spring until a month before a hard killing frost. Zones 4-8.

Perovskia or Russian Sage

An award-winning ornamental. Aromatic velvety gray leaves fill the air with a clean camphor scent and brilliant purple-blue flowers offset the foliage. This treat for your nose and eyes is wonderful in dried flower decorations. Bees like it. Very hardy and grows to 4’ tall. It does best in full sun and well-drained garden soil. It is tolerant of dry soils. Use as an accent plant or massed as a tall ground cover or hedge. Russian sage is characterized as a sub-shrub with a woody base. Potted plants should be planted at the same depth as they were in the pot. Plant from spring till one month before a hard killing frost. Zone 3-8.

Echinacea Purpurea ‘Magnus’

This is a popular variety, whose petals are an especially vibrant carmine-rose shade and are held almost horizontally. The bloom has a more open face, rather than the shuttlecock shape of the species. Blooms June to September and grows to 40" tall. It prefers full sun with well-drained garden soil. It is very drought tolerant. Can be used as a specimen or massed (it will reseed). It is a good choice for meadow or prairie gardens. ‘Magnus’ is excellent for cut flowers. Zones 3-8.

Campanula Persicifolia ‘Chettle Charm’

The common name for this campanula is Peach-leaf bellflower. It is easily grown in average, medium wet, well-drained soil in full sun to part shade. It prefers part shade in warmer climates and dislikes the extreme summer heat of the deep South. It needs regular moisture. Under optimum conditions plants will spread both by self-seeding and by underground runners (rhizomes). It should be divided in fall every 3 to 4 years. Its shape is a rosette-forming, upright perennial which blooms on stiff stems 1 to 3 feet tall. The flowers are creamy white, edged with lavender blue. ‘Chettle Charm’ is synonymous with and sometimes sold as ‘George Chisel.’ Zones 4-8.

Salvia ‘May Night’

This salvia is a wonderful late-spring blooming perennial, 2 to 2 1/2 feet tall. Rigid spikes of dark blue-black flowers appear over aromatic blue-gray leaves in May and June. Full sun is preferred for good bloom. It likes average to dry garden soil and will withstand drought once established. It dislikes winter wet conditions. It can be used as a specimen, in borders, or massed. Potted plants may be planted any time in the growing season. Plant at the same depth as they were in the pot. Water well till plants are established. Zones 4-8; in colder areas a winter mulch is beneficial

Woody Shrubs

We have two woody shrubs that have been provided by Penn State. They have both been in the Trial Garden since the very beginning. Both have been transplanted twice.

Vitex

Vitex has two common names: summer lilac and Chaste tree. This is actually a southern shrub which will grow as far north as Zone 6. Every winter since we have had this shrub we have cut the stems back to 6 to 12 inches. It should be cut back around March or April the same as a butterfly bush (Buddlia). It begins to leaf out in late spring. The shrub renews itself with many branches that will produce the current year’s bloom. The flowers are lavender-blue panicles that are similar to erect lilac blooms or butterfly bush blooms. The flowers are sweet-smelling and useful in late-season bouquets to soften the usual hot fall colors. The lance- shaped leaves are unusual, attractive, and fragrant. So far we have had no problems with insects or disease. The shrub always looks good and the bees and butterflies love it, Zone 6 is the northern limit.

Weigela ‘Wine and Roses’

Weigela is thought of as an old-fashioned shrub from your grandmother’s garden. But this one is new and improved. Starting with the dark purple leaves that attract attention and stay purple all season, then the flowers that are a vibrant burst of hot pink or red trumpet-like flowers in spring. A bonus is that the shrub often reblooms late in the summer. Hummingbirds love the flowers; they can be used as cut flowers and the branches can be included in arrangements. It should be planted in full sun in average soil. There are no serious pest problems. Zones 4-8.

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