Ranunculus repens 'Flore Pleno' - Doubleflowered Creeping Buttercup

Flower Color

Height

Season

Pests

Uses

Propagation

 yellow

18" 

late summer 

few

border, naturalized areas

division

Performance - Creeping buttercup grows best in full sun with moist soil.  It will spread quickly in moist soils and is best planted in naturalized areas where it can spread.  It is known to produce an abundance of bright yellow flowers.

Comments - This can be an aggressive plant in the landscape. 'Susan's Song' is also excellent.

Ratidiba pinnata

Ratibida - Prairie Coneflower

Flower Color

Height

Season

Pests

Uses

Propagation

 yellow

24"- 40"

summer

few

border, wildflower meadow

seed, division

Performance - Prairie coneflower is native to the central and north central regions of the U.S. It is a reliable perennial for Kentucky landscapes and grows best in dry areas that are in full sun.

Comments - It is excellent to grow in meadows. Consider trimming spent flowers to promote reblooming.

Ratibida columnifera – Prairie Coneflower, Mexican Hat, Long-head Coneflower

Ratibida pinnata – Prairie Coneflower – This plant is native to Kentucky and is well suited to natural landscapes and wildflower gardens.

Castor bean ‘Carmencita Red’

Ricinus communis - Castor Bean, Castor Oil Plant, Wonder Plant

Flower Color

Height

Season

Pests

Uses

Propagation

red, white, pink

3' - 8' 

summer 

few

border, background

seed

Performance - Castor bean is a traditional annual that is now less common in Kentucky landscapes. The fast-growing plants are strikingly large and have large palmately divided bronze green leaves. The large prickly seed pods are visible in late summer and fall.

Comments - This plant was common because it is so easy to save the seed from one year to the next. Unfortunately the seed and many plant parts are quite poisonous. This is not a plant for gardens where children and pets are common.

Varieties - 'Carmencita Red, Pink', 'Impala', 'Red Spire', 'Zanzibarensis'

Rosa - Rose

Flower Color

Height

Season

Pests

Uses

Propagation

white, pink, salmon, rose, red, lavender, yellow, orange

2' - 8' 

summer 

aphids, spider mites, Japanese beetles, rose midge, powdery mildew, black spot

border, cut flower, specimen, collection

grafting (budding), cuttings

Performance - Roses are a favorite garden flower in Kentucky gardens. Many are reliable perennial, but many can be damaged by late spring freezes and cold winters. Roses should be planted in full sun gardens with good garden soil. Be sure to space plants sufficiently for good air movement (to reduce diseases) and for easy access for pruning and pesticide applications. It would also be wise to use drip or trickle irrigation to reduce diseases. Most roses are high maintenance garden plants, so you should be prepared.

Comments - Roses are a very large, diverse group of garden plants. It would be wise to join a local rose society, if you wish to become adept at rose care. In general, the old garden roses are the most disease resistant, but they may also have only single flowers and may flower only once per year. The modern roses generally require regular pruning, fertilization and pesticide applications.

Varieties - There is no list of recommended varieties or cultivars. There are so many roses, it would be difficult to trial them all. Again, contact with local rose growers (rosarians) in a local rose society will be a great help. Visits to the rose garden at the UK Arboretum in Lexington and at the Kentucky Fairgrounds and Exposition Center in Louisville will assist your selections.

Rosmarinus officinalis - Rosemary

Flower Color

Height

Season

Pests

Uses

Propagation

pale blue

12"- 40"

summer 

aphids, mealybugs, spider mites, powdery mildew

herb, border, container

cuttings, seed

Performance - Rosemary is not a reliable perennial for Kentucky gardens. It is best to grow it in a container outside, which can be brought indoors during the winter. This container could be buried in the soil or maintained on a patio. It prefers partial to full sun outdoors and full sun indoors. Letting the soil dry out completely will kill Rosemary instantly.

Comments - This is an aromatic herb used in many culinary dishes. The fragrant pine scent is excellent for soaps, lotions and oils. It generally has few problems with disease until it is brought into the house for the winter. Cuttings are the best method for propagation because seeds are not usually true to type and are not vigorous. Rosemary is a symbol of remembrance, friendship and love.

Varieties - 'Albus', 'Athens Blue Spires', 'Beneton', 'Prostratus'

Rudbeckia – Black-eyed Susan, Coneflower

Flower Color

Height

Season

Pests

Uses

Propagation

yellow

2-6 ft.

summer

powdery mildew

border, cut, meadow

seed, division


Performance - Coneflowers can be annual or perennial in Kentucky gardens, depending on the species and the cultivars. Rudbeckias should be planted in good garden soils in full sun gardens. They are relatively drought tolerant because many are native to the state.

R. fulgida var. sullivanti 'Goldsturm'- Orange Coneflower, Black-eyed Susan - This is an excellent cultivar, but it should be propagated only from cuttings. Plants can produce large clumps because they will self-sow. The plants can be considered as a short-lived perennial, but they will remain in the garden for many years. ‘Goldsturm’ is not as affected by powdery mildew as other Rudbeckias. This was the 1999 Perennial Plant of the Year from the Perennial Plant Association and an excellent plant for Kentucky gardens.

R. hirta - Black-eyed Susan, Gloriosa Daisy - A native Kentucky wildflower, commonly seen in mid summer along roadsides and in the medians of the interstate highways. This annual will self-sow quite easily in gardens and is a common plant used for wildflower garden mixes. Excellent cultivars have been developed from this species and others. They are generally considered annuals, but may perform as perennials for a few years. 'Becky' Mix, 'Goldilocks', 'Indian Summer', 'Irish Eyes', 'Marmalade', ‘Prairie Sun’, 'Rustic Colors,' 'Sonora', 'Toto'.

R. subtomentosa - Sweet Coneflower - A Kentucky native.

Orange Coneflower ‘Goldsturm’

Black-eyed Susan ‘Prairie Sun’

More information and photos are available in HortFact 50.12 06 – Coneflowers, Black-eyed Susans.

Ruta graveolens - Common Rue, Herb-of-Grace

Flower Color

Height

Season

Pests

Uses

Propagation

yellow

24"- 36"

midsummer 

few

herb, edging, borders

seed or cutting

Performance - Rue is a reliable perennial in Kentucky gardens and grows best in full sun with well drained soil. It will become woody and unattractive if not cut back to the old wood every spring. It is primarily grown for its unique blue-gray foliage.

Comments - Old folk lore suggest growing next to roses as a natural insecticide for many pests of roses. Rue will cause dermatitis in some individuals especially when the climate is hot and humid.