HO-47 
LOW MAINTENANCE ANNUAL FLOWERS FOR KENTUCKY GARDENS
ISSUED: 2-80
REVISED: 7-90
Bob Anderson and Sharon Bale

Selected types of annual flowers produce a summer full of color in Kentucky gardens with little care. These plants produce brightly colored flowers, foliage or fruit from early June until frost in the fall. The display of color is consistent throughout the season and the plants require little maintenance regardless of the weather.
During the long Kentucky summer, a low maintenance annual flower must:

1) Be thoroughly adapted to and not simply tolerant of hot, dry conditions.
2) Demonstrate insect and disease resistance during weather conditions that promote them.
3) Require no maintenance labor to prune or remove flower blossoms.
4) Display consistent color and plant size all summer until frost.
5) Be uniform when grown from seed and cuttings and be available from retailers of plant materials. A broad range of color choices is also desirable. By choosing a combination of these plants, you should be able to have a maintenance-free flower garden filled with color (see Table 1 ).

Selected Cultivars
Vinca, Periwinkle (Catharanthus roseus)
The glossy dark green foliage contrasts nicely with the profuse lavender, pink or white flowers. Plants are very consistent and form an outstanding ground cover. They are also quite attractive in planters and other containers.
Vinca is a warm season annual and although it continues to bloom and produce an effective display until frost, the bloom size and number may decrease in early fall.
Creeping Habit (4-6 inches tall)
Polka Dot
Carpet Series -- Dawn, Pink, Snow, Magic

Dwarf Habit (8-10 inches tall)
Little Series -- Blanche, Bright Eye, Delicata, Pinkie, Linda
Parasol, Pretty in Pink, Pretty in Rose, Pretty in White
Grape Cooler, Peppermint Cooler, Blush Cooler
Tropicana Series -- Blush, Bright-Eye, Pink, Rose

Begonia (Begonia semperflorens x cultorum)
The bedding begonia, commonly referred to as the wax or fibrous-rooted begonia is one of the most popular bedding plants throughout the country. Begonias have blooms in shades of pink, red and white. The diversity of plant habit, leaf form and color (green and bronze) produce many possible choices for the garden. Begonias that are well established in the spring withstand drought and heat conditions in August as well as any other plant.
Begonias are not suitable for home production. The plants are relatively expensive when compared to other annuals but the added cost is due to the long production time necessary in commercial greenhouses.
Most begonia cultivars do well in Kentucky. The following cultivars meet certain foliage and height criteria.

Bronze Foliage
Dwarf (6-9 inches tall)
Cocktail Series -- Whiskey, Gin, Vodka, Rum, Brandy
Partyflirt, Partyfriend

Tall (10-14 inches tall)
Danica Series -- Rose, Red
Othello
Expresso Series -- Rose, Scarlet, White

Green Foliage
Dwarf (6-9 inches tall)
Viva
Linda
Olympia Series
Varsity Series -- Deep Rose, Rose, Scarlet, White

Tall (10-14 inches tall)
Partylove
Hot Tip Series -- Bicolor, Pink, Red, Rose, Salmon, White

Coleus (Coleus x hybridus)
Coleus are grown for the effect of the foliage rather than the blooms. All colors of foliage (except purple and blue) are available from various cultivars that perform well in shade or semi-shade. The plants are available in diverse plant size, leaf size and form, and leaf color combinations. Coleus plants are more vigorous and produce more branches when flowers stems are removed.
Flowers are blue. Foliage colors are lavender, green, yellow, orange, red, bronze, pink, salmon, and white.
Most cultivars perform well. The following choices are readily available are:

Dwarf (10-12 inches tall)
Fairway Series
Wizard Series
Jazz Series

Medium (12-18 inches tall)
Fiji Series (fringed)
Saber Series
Carefree Series

Tall (15-30 inches tall)
Rainbow Series

Impatiens (Impatiens wallerana)
Impatiens, also known as sultana, Busy Lizzie or bloomin' fool, is well known to all home gardeners. Few plants can match the number of flowers produced by impatiens. Shady or semi-sun locations are ideal. Plants in a sunny location may wilt in mid afternoon but generally recover by early evening. A wide range of bloom colors is available.
Flowers are lavender, orange, red, pink, salmon, and white. Foliage is green.

Dwarf (9-12 inches tall)
Accent Series
Super Elfin Series
Futura Series
Impulse Series
Novette Series
Deco Series
Tempo Series

Semi-dwarf (10-15 inches tall)
Shady Lady Series
Gem Series
Futura Series
Blitz 2000 Series

Ornamental Peppers (Capsicum annuum)
Ornamental peppers are not as readily available as they once were. Those available are an excellent choice for Kentucky gardens. Ornamental peppers grow vigorously throughout the summer to produce an eye-catching display of bright red and orange fruit from August until frost. The fruit is edible but extremely hot! These plants are also effective in containers.
Flowers are purple, lavender, orange, red, and white. Foliage is purple, green and white.

Tapered Fruit
Candlelight
Fips
Fiesta

Round Fruit
Holiday Cheer

Blue Salvia, Mealy Cup Sage (Salvia farinacea)
Blue salvia is a maintenance-free, blue or white flowered annual for full sun locations in Kentucky gardens. 'Victoria' is a particularly good choice producing a bushy, vigorous plant 18-20 inches tall with dark blue flowers and green foliage.
The flowers can be used fresh or dried. The plants attract a large number of bees, which may be advantageous or a concern to some home gardeners. The plants may readily self sow, which could be a future maintenance problem.

( 18-20 inches tall)
Victoria -- deep blue flowers
Rhea -- deep blue flowers
Silver White -- white flowers

(30-36 inches tall)
Blue Bedder -- blue flowers

Creeping Zinnia (Sanvitalia procumbens)
Sanvitalia, known as creeping zinnia, may be just the answer for an area where a low, creeping, colorful plant is desired. This plant has an average height of 6 inches and is generally covered with bright orange daisy-like flowers with a dark center throughout the gardening season. The plant is generally not available as a spring bedding plant transplant, yet can be started at home indoors. 'Mandarin Orange' is a 1986 All America Selection Winner, the foliage is green. 'Double Sprite Yellow' has bright yellow flowers.
Gomphrena, Globe Amaranth (Gomphrena globosa)
Globe Amaranth is a vigorous, carefree plant for full sun locations. This plant is adapted to hot, dry garden sites. The cultivar 'Buddy' produces deep lavender to purple clover-like blossoms from mid June until frost on very uniform plants.
Globe Amaranth blooms can be used fresh or dried. Harvest blossoms before they reach peak bloom to retain the best color. The foliage is green.

(8-12 inches tall)
Buddy -- violet to purple flowers
Cissy -- white flowers

(18-24 inches tall)
Strawberry Fields -- strawberry red flowers
QIS Series -- Lilac, Pink, Purple, Rose, White, Red, Orange

Ornamental Basil (Ocimum basilicum)
The ornamental basils are similar to culinary basil except that the foliage is deep purple. Plants may be used in semi-shade, but the best leaf color and plant habit is developed in full sun locations. White flower spikes are produced at times during the summer but these are not showy and can be removed to keep the plant bushy and full.
These plants have the distinct flavor of green basil and can be used as an herb.

( 18-20 inches tall)
Dark Opal
Purple Ruffles -- All America Selections Winner
Green Goddess, Purple Goddess

Polka Dot Plant (Hypoestes phyllostachya)
Polka Dot Plant matches its name very well because it has small dark green leaves spotted with bright pink to white spots. This plant has been used indoors but for uniform, vigorous growth it performs best outdoors where it is virtually maintenance-free.
The plants grow 24 to 36 inches tall and make an excellent annual hedge or a carefree backdrop for other flowering annuals. It has white flowers.

(24-36 inches tall)
Pink Splash, White Splash
Confetti Series -- Burgandy, Red, Rose, White

Cleome, Spider Flower (Cleome hasslerana)
Cleome or spider flower is one of the tallest annual flowers that truly thrives under Kentucky' s summer climate. Spider flower is generally used as a background plant or cutflower. The large flower spikes with pink and white flowers and pendulous seed pods are a distinct addition to the flower garden. The flower spikes continue to get taller throughout the summer and may reach 5 to 7 ft in a full sun location. Plants may be considered perennial by some gardeners because the plants reseed readily.
Queen Series -- Cherry, Pink, Rose, Violet, White

Dusty Miller (Chrysanthemum ptarmiciflorum, Cineraria maritima, Senecio cineraria)
Several different genera and species are referred to as "Dusty Miller." The plants are grown for the effect of the silvery foliage and may overwinter. Various leaf forms and textures are available and all can be quite effective as an edging plant or in mass display.

(8 inches tall)
Silver Queen -- lacinated silver white foliage
Snow Storm

(12 inches tall)
Silverdust -- finely divided foliage

Melampodium (Melampodium paludosum)
The bushy, well branched plants produce yellow, daisy-like flowers on green foliage all summer long. They are heat tolerant with no apparent disease or pest problems. The plants may self sow.

( 18-24 inches tall)
Medallion
Showstar

Abelmoschus (Abelmoschus moscheutos)
The plants are 15 to 20 inches tall and produce red or pink blooms on green foliage. The plants are closely related to the Hibiscus and have similar blooms. Each bloom only lasts one day but the plants produce numerous flower buds. They do best in full sun and may self sow.

Pacific Series -- Scarlet, Pink

Table 1. Planting and Color Information for Low Maintenance Annual Flowers
Spacing
(in.)
Ht
(in.)
Sun
Exposure
Semi-Shade
Shade
Wax Begonia, Bedding Begonia 12 6-14
X
X
X
Vinca, Madagasgar Periwinkle 12 4-12
X
     
Impatiens, Sultana, Busy Lizzy 12-18 8-18   
X
X
Coleus 12-24 10-30
X
X
X
Ornamental Pepper 10-12 10-14
X
    
Blue Salvia 12-18 18-24
X
     
Creeping Zinnia 10-12 6-8
X
     
'Buddy' Globe Amaranth 12 24
X
     
'Dark Opal' Ornamental Basil 12-18 20-24
X
X
  
Polka Dot Plant 18 24-36
X
X
  
Cleome, Spider Flower 24-36 36-60
X
     
Dusty Miller 10-12 8-14
X
     
Melampodium 12-14 18-24
X
     
Abelmoschus 10-12 15-20
X
     

Propagation
All recommended cultivars of these preferred annual flowers are propagated from seed. Unfortunately, begonia, vinca and impatiens seed are difficult to germinate. Seed of all others could be germinated by a home gardener with little difficulty (see Cooperative Extension publication H0-56, Starting Plants from Seed at Home).

Soil
Typical garden soils are adequate for growing these selected plants. Garden soils that are amended annually with organic matter provide good water drainage and aeration and retain adequate moisture and nutrients. Adding organic matter from any source ( e.g. straw, rotted leaves or manure, grass clippings, peat moss, etc.) is the best way to assure a beautiful display from your plants.
Be sure to choose a well-drained garden site. If you must use a low area for your garden, build a raised bed to be sure drainage is adequate. Add extra organic matter to gardens in shady locations since these areas tend to dry more slowly than do sunny locations. Begonias, impatiens and coleus prefer organic soils when grown in the shade.
Patio containers, window boxes and pots should always allow water to drain. Use growing media in your containers; garden soil is NOT recommended. The best growing media for these plants are the professionally prepared, packaged media (e.g. Pro-Mix®, Peters® Potting Soil, Metro-Mix®, Ball Growing Mix®, etc.) used by greenhouses for plant production. A satisfactory home-made growing medium is 1 part sterile garden soil, 1 or 2 parts of sphagnum moss peat, black (Michigan) peat or compost, and 1 part perlite or coarse sand.

Water and Fertilizer
The selected plants were chosen partly because no special water or fertilizer applications are generally necessary. They will show maximum growth if you follow these steps:

1. Plants need about 1 inch of water per week. If rain does not supply enough water, apply the necessary water in one application, preferably before 7 p.m.
2. Plants growing in containers need water every 2 to 4 days throughout the summer.
3. Water new transplants with a complete water-soluble fertilizer (e.g. 20-20-20) shortly after transplanting.
4. Granular, dry fertilizer can be added to the garden when it is tilled in the spring. Use about 1 lb of 15-15-15 (nitrogen -- potassium -- phosphorus) fertilizer/100 sq ft of garden or 11/2 lb of 10-10-10 or 3 lb of 5-10-5 fertilizer/100 sq ft. Begonias and vinca are light feeders, so for them, use half these rates or less.
5. Dry fertilizer or water soluble fertilizer applied in early August stimulates late summer growth. Apply dry fertilizer between the plants, scratch it into the soil and water the garden thoroughly. Use dry fertilizer at half the rates described above. Water-soluble fertilizers are easiest to use for container plants. Apply them according to the label recommendation.

Pests
Most of Kentucky's common insects and diseases do not harm these plants. However, plants purchased with insects problems will probably continue to have these problems. Spider mites and mealybugs, brought into your garden on plants, can damage impatiens, coleus and vinca. Also, blue salvia could be purchased with a whitefly problem.
Disease problems on the leaves of these plants are nearly nonexistent. However, root and stem rotting organisms kill plants when soil drainage is inadequate.
Weeds present little problem since these plants grow vigorously enough to out-compete most weeds. If hand weeding is not feasible, these plants grow well with organic or plastic mulches or when recommended herbicides are used correctly.

About the Authors
Bob Anderson has worked with commercial flower growers in Kentucky for 17 years. His special interests include house plants, annual and perennial flowers, and he directs research on mechanized production of cutflowers. He edits the monthly, Kentucky Hints and Facts, for commercial greenhouse operators and is actively involved with the University of Kentucky Arboretum.
Sharon Bale has been an Extension Floriculture Specialist since 1975. She works with home horticulture, especially annuals and perennial flowers, herbs and floral design. For at least 12 years she has been an All-America Selection judge, helping to select which new flower cultivars win national acclaim as All America Selections.
Trade names are used solely for identification. No product endorsement is implied, nor is discrimination intended, to the exclusion of comparable products.