Iberis sempervirens - Candytuft

Flower Color

Height

Season

Pests

Uses

Propagation

white

6-10"

early spring

few

border, edging

seed, cuttings 

Performance - Candytuft is a reliable, cool season perennial plant grown in Kentucky gardens. It is best to plant candytuft in a location that receives full sun in the spring and some shade during the summer. They require a well-drained soil. The plants may suffer winter dieback in full sun. Prune after bloom to maintain compact growth habit.

Comments - Most of the cultivars are propagated by cuttings. This is a common perennial used for spring show in much the same way as creeping phlox. Unfortunately, they may look pretty ragged through the summer, so it is best to plant them among other garden flowers.

Varieties - 'Autumn Snow', 'Alexander's White', 'Purity', 'Snowflake'.

Impatiens - Impatiens, Sultana, New Guinea Impatiens, Balsam

Flower Color

Height

Season

Pests

Uses

Propagation

all colors, including bicolor, 
except blue

10"- 30"

summer

damping off and slugs

shaded areas, planters and containers 

seed, cuttings

Impatiens are reliable and very popular annuals for Kentucky gardens. They are the number one selling plant in Kentucky and most of the U.S. because they are so easy to grow. They grow best in shaded areas with moist, well drained soil. Impatiens can grow in full sun as long as they have abundant water and highly organic, amended soil.

I. balsamina - Balsam, Touch-Me-Not

Performance - Balsam is a traditional annual flower that was quite common in Kentucky gardens. The plants sell sow quite efficiently, so they remain in shady gardens for many years. Some gardeners consider this plant to be an undesirable weed in their garden. The seed pods of balsam swell and pop when touched (to disperse the seed), thus the name Touch-Me-Not.

Varieties - 'Color Parade' mix, 'Tom Thumb' mix.

New Guinea impatiens ‘Sonic Purple’

I. New Guinea Group - New Guinea Impatiens

Performance - New Guinea impatiens have been used as a garden and container flower for approximately 30 years. The cultivars are derived from plants collected in New Guinea in the 1960s by USDA scientists. Varieties and appearance have changed significantly over the 30 years. Initially, varieties with variegated leaves were the trend, but recent breeding has focused on large flowered varieties with bright clear colors. New Guinea impatiens were initially sold in the state as plants that preferred full sun conditions, but this is not best. These plants prefer partial shade to shade conditions and are most commonly sold in hanging baskets or for use in patio containers. These annual flowers are great performers for Kentucky gardeners and are relatively easy to grow.

Varieties - from seed - 'Borneo' series, 'Java' series (8 colors), 'Spectra' series, 'Tango'.
from cuttings - 'Baby Bonita' series, 'Celebration' series (24 colors), 'Celebrette' series (16 colors), 'Electra' series, 'Harmony' series (30 colors), 'Lasting Impression' series (15 colors), 'Ovation' series (14 colors), 'Paradise' series (23 colors), 'Pretty Girl' series, 'Pure Beauty' series (15 colors), 'Pizzazz' series, 'Sunshine' series.

Impatiens wallerana - Impatiens, Sultana, Patient Lucy, Busy Lizzie

Performance - Impatiens are the most commonly sold garden flower in the state because they are so easy to grow. Additionally, they are probably the best annual flower for shady conditions in the landscape. They flower freely all summer as long as they get enough water. If plants don't seem to be growing well, just be sure to water more frequently and add some fertilizer and they will begin to grow rapidly again. Impatiens are susceptible to some root and stem diseases, that may remain in the soil. If this occurs, you will not be able to grow impatiens in that site again.

Varieties - 'Accent' series (26 colors), 'Dazzler' series (21 colors), 'Deco' series (8 colors), 'Infinity' series, 'Mosaic' series, 'ShowStopper' series (18 colors), 'Stardust' series, 'Super Elfin' series (22 colors), 'Swirl' series, 'Tempo' series (27 colors)

Double Impatiens - from seed - 'Carousel' series, 'Tutu' series, 'Victorian Rose'
from cuttings - 'Cameo' series, 'Fiesta' series (13 colors), 'Gem' series, 'Golden' series, 'Ice' series (variegated foliage), 'Rosebud' series, 'Tioga' series.

Impatiens at Bodger Seed Company

Double impatiens at Pan American Seed Co.

Japanese Blood GrassImperata cylindrica 'Red Baron' or 'Rubra' - Japanese Blood Grass

Flower Color

Height

Season

Pests

Uses

Propagation

brown, unimportant

12"- 18"

not important

few

masses in borders

spring division

Performance - Japanese blood grass is generally perennial in Kentucky, but gardeners and landscapers have had difficulty with it. It is grown primarily for the red variegated foliage that lends a striking contrast in any garden. It grows best in full sun with moist soil that is well drained. It will tolerate shade, but the intensity of the color will lessen. Poor growth is a sure bet if planted in poorly drained soil, such as heavy clay, or hot, dry areas.

Comments - This is one of the few grasses which produce red foliage.

Ipomoea - Morning Glory, Sweet Potato

Flower Color

Height

Season

Pests

Uses

Propagation

 blue, pink or white

8'-10' vine 

summer 

few

screen or trellis, containers, borders

seed, cuttings

I. batatas - Sweet Potato

Performance - Ornamental sweet potatoes are vigorous spreading plants that are grown as annuals in Kentucky gardens. They do produce tubers, that can be saved, but they are of little value as edible sweet potatoes. The plants prefer full sun locations and well drained soils. In containers, they need plenty of water and fertilizer through the summer. These plants are vigorous and will “out-compete” most neighboring plants, so prune as necessary.

Varieties - 'Blackie', 'Marguerite', 'Tricolor'.

Sweet Potato ‘Blackie’

Sweet Potato ‘Marguerite’

Sweet Potato ‘Tricolor’

Ipomea ‘Cameo Elegance’ at Takii Seed Company

 

I. tricolor - Morning Glory, I. purpurea - Common Morning Glory

Performance - Morning glory grows best in full sun with well drained soil.  If planted in fertile soil it will produce an abundance of foliage, but few flowers. Since it is a vine, it is best to plant many together, otherwise it will have a spindly appearance. It is called morning glory because the flowers only open in the morning and then close as the heat increases. This plant grows wild throughout many states and is considered a weed to many people. Plus, this plant has a number of weedy relatives. If propagated by seed, scarification is needed. This is done by scratching the seed coat so that it can take up water.

Varieties - 'Minibar Rose', 'Blue Silk', 'Mt. Fuji' mix, 'Tie Dye', ‘Cameo Elegance’.

Iris - Flag

Iris cristata - Crested Iris

Flower Color

Height

Season

Pests

Uses

Propagation

violet

6"

early to midspring

slugs

front of border, rock garden, woodland garden

early fall division, seeds

Performance - Crested iris is a reliable perennial in Kentucky gardens and is native to the state. It grows best in partial shade with well drained soil that has been amended with sand or leaf mold. Highly fertile soils tend to promote more vegetative growth than flowers. This plant will grow better along a slope that drains water well.  The petals are violet, but the striking feature is the bright yellow or white center which branches along the petals.

Iris ensata - Japanese Iris, Sword Leaf Iris (also called I. kaempferi)

Flower Color

Height

Season

Pests

Uses

Propagation

blue, purple, lavender

18" - 24"

early to midsummer

thrips

along water or moist garden sites

division

Performance - Japanese iris is a reliable and excellent perennial plant for Kentucky gardens. They grow best in moist, organic soils and are often used along water ways, ponds, fountains and streams. If the right location can be found elsewhere with abundant moisture, they are impressive in mass plantings. They grow best in full sun to partial shade with highly amended organic matter, with soil that is slightly acidic. Alkaline soils will kill this plant. Japanese iris can be left undisturbed for many years if put in the right environment. They bloom a month later than tall bearded iris.

Iris hybrids - Bearded Iris

Flower Color

Height

Season

Pests

Uses

Propagation

numerous

2' - 4'

early summer

iris borer, leaf spots

perennial border

division

Performance -

Bearded irises are reliable, easy-to-grow perennial plants and the most common iris grown in Kentucky gardens. They grow best in full sun locations with well drained soils. Good drainage is essential to prevent bacterial soft rot. Bearded iris is particularly susceptible to bacterial soft rot when iris borers have invaded. The iris borer larvae tunnel through the rhizomes and expose them to bacteria. Insecticidal spray is essential in the spring when the plants are approximately 3" tall and repeated at weekly intervals for 2 weeks. Foliage should be cleaned up in the fall to prevent the laying of eggs for next year. Bearded irises prefer to be grown in beds without mulch, so be sure to use a pre-emergent herbicide regularly to control weeds. Bearded irises are classified as miniature dwarf, standard dwarf, intermediate and tall, with tall being the largest group with thousands of varieties. Check with members of local iris societies or local growers for more information on variety selection.

Iris pallida - Sweet Iris, Orris Root

Flower Color

Height

Season

Pests

Uses

Propagation

bluish purple

3' 

late spring

iris borer

accent, border

summer clump division

Performance - Sweet Iris is not as popular as the other relatives, but it certainly is an easy plant to grow with little maintenance living many years without division or fertilization. A well drained soil and full sun are the only requirements to grow this plant. The dried rhizomes are sometimes used for the extraction of perfumes.

Iris pseudacorus - Yellow Flag, Yellow Iris

Flower Color

Height

Season

Pests

Uses

Propagation

yellow

5'

early summer

few

streams, ponds

division, seed

Performance - Yellow flag is a reliable perennial flower for Kentucky gardens. It is an excellent plant to grow along streams or ponds. It will not take long to become established and colonize. It grows best in soils with high moisture in full sun. If placed in the shade the soil should be slightly drier. Yellow flag naturalizes well throughout the United States. Prevent them from spreading by removing the seed heads.

Siberian iris ‘White Swirl’

 Iris sibirica - Siberian Iris

Flower Color

Height

Season

Pests

Uses

Propagation

white, blue, purple

2' - 4'

late spring

few

perennial border

spring division

Performance - Siberian iris is a reliable and under-used perennial flower for Kentucky gardens. It grows best in full sun to partial shade in fertile, moist soils that are slightly acidic, but they will tolerate poor, dry soils. The habit of Siberian iris is different from the bearded or Japanese iris in that the foliage is more refined and the clumps are vase shaped rather than a fan. Division is best but is almost never needed.  Siberian iris is the best iris to choose for more southern, hot gardens, especially because it is not affected by the iris borer.