HO-80: Annual Flowers

Annual Flowers

Introduction

Annuals offer almost unlimited versatility. They’re available in a wide range of colors and sizes, and various species offer solutions for sun and shade plantings.

Each year new cultivars are being introduced by seed companies. Most of these are hybrids which have been selected for their superiority over existing cultivars or species. When making selections, consult the latest descriptions in publications and catalogs. Also visit Floricultural demonstrations such as the Purdue University Horticulture Gardens and the University of Illinois Trial Garden.

Author

Michael N. Dana

Annual Flowers

*Note:

A-Sow seed directly in bed, border or in rows where they are to flower.
B-Sow seed indoors or in hotbeds and transplant to garden.
C-Sow seed in coldframe and transplant to garden.

Annual Flowers
Botanical common name	Situation	Color	Height (inches/centimeters)	Flowering season	Sowing*	Remarks
Flossflower Ageratum houstonianum	sun semi-shade	blue, lavender, pink, white	6-18/15-46	June-Sept.	A-May B-April	The dwarf types are well suited for bedding: the taller ones are good for mass effects and cuttings.
Hollyhock Alcea rosea	sun	assorted	12-72/31-1.8M.	July-Sept.	A-May	The annual varieties are similar to the biennial" ones. Taller varieties are for background or screen planting only. Dwarf types are now available.
Tampala Amaranthus tricolor	sun	foliage — red-green variegated	6-36/15-91	June-Sept.	A-May B-April	Desirable for colorful foliage. Often susceptible to diseases which may kill plants.
Common Snapdragon Antirrhinum majus	sun	assorted	6-36/15-91	June-Oct.	A-May B-March C-March	The semi-tall and dwarf sorts are best suited, for they require no staking. Well suited for cutting and bedding. Use rust resistant strains only. New varieties are continuous bloomers.
African Daisy Arctotis stoechadifolia	sun; light, sandy soil	white, red, orange, yellow pink, apricot	9-10/3-25	July-Sept.	A-May B-March	Best in areas with cool night temperatures.
Bedding Begonia, Wax Begonia Begonia x semper-florens-cultorum	sun, shade (depends on variety)	assorted flower and foliage	6-15/15-38	June-Sept.	B-January	Many new flower and foliage types. Ideal for shady locations.
Swan-River Daisy Brachyscome iberidifolia	sun, semi-shade	assorted	12/31	July-Sept.	A-May B-April	A free-flowering, dwarf-growing annual which is well suited for edging flower beds.
Flowering Kale and Flowering Cabbage Brassica oleracea	sun	red or white variegation on blue-green foliage	10-12/25	April-Oct.	B-April	Color is best in cool weather. Control insects such as cabbage worm and cabbage looper.
Amethyst Flower Browallia speciosa	semi-shade	blue, white	8-12/20-31	July-Sept.	A-May	A free-flowering plant which is well suited for bedding in shady areas.
Calendula, Pot Marigold Calendula officinalis	semi-shade	yellow, orange	10-15/25-38	July-Oct.	A-April B-April or March	An old-fashioned flowering plant which has been greatly improved by plant breeding. It is well suited for cutting.
China Aster Callistephus chinensis	sun, semi-shade	assorted	12-36/31-91	July-Oct.	A-April B-April	Asters are very susceptible to Aster Wilt and Aster Yellows. Buy seed of wilt resistant varieties. Plant asters in a new location each year and keep leaf hoppers and aphids under control.
Ornamental Pepper Capsicum annuum	sun	white	10/25	June-Oct.	B-April	Grown for colorful fruit in black-red, purple, red, yellow. Many cultivars available.
Madagascar Periwinkle Catharanthus rosea	sun, semi-shade	assorted	12-15/31-38	June-Oct.	B-April, March	A free-flowering plant with dark laurel-like foliage. Well suited for bedding.
Crested Coxcomb Celosia cristata	sun	yellow, orange, red	6-36/15-91	June-Oct.	A-May B-April	Extremely easy to grow. Heat and drought resistant. Excellent for drying.
Plume Celosia Celosia cristata	sun	yellow, orange, red	6-36/15-91	June-Oct.	A-May B-April	Extremely easy to grow. Heat and drought resistant. Excellent for drying.
Cornflower Centaurea cyanus	sun	assorted	20-30/51-76	June-Oct.	A-April, May, June B-April	If continuous flowering is desired, make sowings at monthly intervals. They are self-feeding after once well established. Suitable for cutting.
Dusty Miller Centaurea gymnocarpa	sun	gray foliage purple foliage	24-30/61-76	Apr.-Oct.	A-May B-March	Grown for foliage.
Sweet-sultan Centaurea moschata	sun	white, yellow, purple	12-20/31-51	July-Sept.	A-May B-April	Sweet-scented flowers of artistic shape. The flowers are borne on long stems and are very suitable for cutting.
Feverfew Chrysanthemum parthenium	sun	yellow	24-36/61-91	June-Aug.	A-May B-March	Aromatic.
Silver Lace Dusty Miller Chrysanthemum parthenium	sun	gray foliage	6-8/15-20	May-Oct.	A-May B-March	Grown for foliage, excellent for edging in borders and planters.
Spiderflower Cleome hasslerana	sun	pink, purple, white	36-48/91-1.2M.	June-Oct.	A-May B-April	Attractive in large beds, tall borders and backgrounds. Stands heat, plants will self-sow.
Coleus, Flame Nettle Coleus x hybridus	shade	green to red foliage	12-30/31-76	June-Sept.	B-March	Excellent plant for shady, moist areas. Many new cultivars available.
Rocket Larkspur Consolida ambigua	sun	pink, blue, white	30/76	June-Sept.	A-April B-May	Perfectly hardy, and after they once become established, will seed themselves.
Calliopsis Coreopsis tinctoria	sun, semi-shade	assorted (reds and yellows)	10-24/25-61	July-Oct.	A-May B-April	An old standby which is well suited for cutting.
Common Cosmos Cosmos bipinnatus	sun	assorted (reds and yellows)	18-60/46-1.5M.	July-Oct.	A-May B-April	Early flowering varieties which begin flowering in July and continue until late autumn, are best suited. They are well suited for background planting.
Chinese Forget-Me-Not Cynoglossum amabile	sun	blue	20/51	July-Sept.	A-May	A plant of easy culture, which produces long stems and flowers suitable for cutting. Remove flowers for continuous bloom.
Dahlia Dahlia pinnata	sun	assorted	6-36/15-91	June-Sept.	B-March	Seeding dahlias often are uneven and flower poorly.
Garden Pink, Rainbow Pink Dianthus chinensis	sun, semi-shade	lavender, pink, white	10-12/25-31	July-Oct.	A-May B-May	Flowers of brilliant colors with sweet fragrance. They are well suited for bedding, edging and cutting.
Common Foxglove Digitalis purpurea	sun, semi-shade	lavender, pink, white	24-48/61-1.2M.	June-July	A-April B-March	Treat as biennial. Gloxinia like flowers, splendid for beds and borders.
Winter Cape-Marigold Dimorphotheca sinuata	sun	orange, yellow, purple	12/31	July-Oct.	A-May B-March	Very attractive and useful for mass plantings and as a cut flower.
Poppy Eschscholzia californica	sun	assorted yellow, orange, red, white	8-12/20-31	July-Sept.	A-May B-April	Dainty flowers and gray-green foliage make this plant a “must” in your garden. Grows under exceedingly dry conditions.
Indian Blanket Gaillardia pulchella	sun	yellow, red	12-24/31-61	July-Oct.	A-May 1 B-April	One of the very best flowering annuals. They are well suited for bedding and cutting. Many of the new hybrids are of merit.
Gazania, Treasure Flower Gazania rigens	sun	white, yellow, red, orange	8-12/20-31	June-Sept.	A-May B-April	Large exotic daisy-like blooms for dwarf masses.
Satin Flower, Clarkia Godetia grandiflora	semi-shade	red, white	12/31	July-Sept.	B-March	Good for beds and borders in cool, moist soil.
Globe Amaranth Gomphrena globosa	sun	orange, red, purple, white	18-30/46-76	July-Oct.	A-May B-April	A showy plant with clover-like flower heads. The flowers may be dried and used in winter bouquets.
Baby’s Breath Gypsophila elegans	sun	white	12-18/31-46	July-Sept.	A-May B-April	he Gypsophilas are quick-blooming, short season plants. Several direct sowings can be made. Excellent filler in arrangements.
Common Sunflower Helianthus annuus	sun	yellow	24-72/61-1.8M.	July-Aug.	A-May	Should be used only as background or screen plantings. Also a wide try a range of dwarf varieties.
Strawflower Bracteantha bracteata	sun	yellow, pink, white, red	20-30/51-76	Aug.-Oct.	A-May B-April, March	Helichrysums are ornamental garden plants and the flowers are highly prized for winter bouquets. Flowers for drying should be gathered when partially unfolded and suspended, heads downward in a cool place until dry.
Common Heliotrope Heliotropium arborescens	sun	purple, white	24-28/61-71	July-Sept.	A-May B-April	Adds fragrance and beauty to any garden, succeeds in any good soil.
Rose Mallow Hibiscus moscheutos	sun	yellow, white, red, pink, mixed	36-60/91-1.5M.	July-Sept.	A-May B-April	Usually freezes to soil level, but produces new growth each season.
Goldencup Hunnemannia fumariifolia	semi-shade	golden yellow	15/38	July-Sept.	B-April	A beautiful golden-yellow, poppy-like flower which is very well suited for cutting. Difficult to transplant unless pot grown.
Globe Candytuft Iberis umbellata	semi-shade	pink, red, purple	12/31	July-Sept.	A-May, June	Well suited for mass planting and edging. A successive planting will provide flowers throughout the summer.
Garden Balsam Impatiens balsamina	sun	white, purple, red	6-24/15-61	June-Oct.	A-May B-April	Old favorite for beds and borders. Does best in rich, well-drained, slightly moist soil.
Impatiens Sultana, Patience Plant Impatiens walleriana	semi-shade	purple, red, pink, white	6-24/15-61	June-Sept.	A-May B-April	Excellent bedding plants. May be cut back and potted to bloom in the house during winter.
Morning Glory Ipomoea spp.	sun	white, pink, red, blue, purple	72+/1.8M.	July-Oct.	A-May	Soak seed in water the night before sowing. Vining plant that can form a temporary dense screen.
Crape Myrtle Lagerstroemia indica	sun	white, pink, red, lavender, blue	21/53	June-Sept.	B-March	This plant may survive the winter in southern Indiana.
Sweet Pea Lathyrus odoratus	semi-shade	white, purple, lavender	60/1.5M. (vine)	June-July	A-Feb., March	Sow sweet peas early in deep rich soil. They require considerable water.
Russian Statice Limonium sinuatum	semi-shade	white, lavender	20/51	July-Sept.	B-April, March	Flowers may be dried and used in winter bouquets.
Flowering Flax Linum grandiflorum	sun	red	12-18/31-46	July-Sept.	A-May B-April	A striking annual plant worthy of more extensive use.
Edging Lobelia Lobelia erinus	semi-shade	blue, red	4-10/10-25	June-Aug.	B-April	Highly desirable for small beds, edging and ribbon bedding.
Edging Lobelia Lobelia erinus	semi-shade	blue, red	4-10/10-25	June-Aug.	B-April	Highly desirable for small beds, edging and ribbon bedding.
Sweet Alyssum Lobularia maritima	semi-shade	white, lavender	4-10/10-25	June-Sept.	A-May B-April	A very desirable edging plant. Is very showy when associated with blue Lobelia, dwarf Ageratum or dwarf forget-me-nots. Long season of bloom. May tend to go out in
Honesty Lunaria annua	sun	red-purple, white	24-36/61-91	July	A-May	The flowers are inconsequential, but the round flat seed pods (a silvery disc) are useful in winter arrangements.
Annual flowering Lupine Lupinus polyphyllus	semi-shade	assorted	24/61	July-Sept.	A-May	Free flowering annual plants, with long, graceful spikes, pea-shaped flowers. Very good for
Unicorn Plant Martynia proboscidea	sun	creamy white	18/46	July-Sept.	B-April	Unusual seed pod for dried arrangements.
Monkey Flower Mimulus x hybridus	shade	red, orange, yellow, blue, violet, purple	12-24/31-61	June-Aug.	B-April C-March	Grow in cool, shaded location, high organic matter.
Four-O’clock Mirabilis jalapa	sun	pink, red, yellow, white	24/61	July-Oct.	A-May	An old-fashioned flower or bushy habit. It is always an interesting subject in any garden.
Bells-of-Ireland Molucella laevis	sun	white	24-36/61-91	July-Sept.	A-Sept. B-March	The enlarged green calyx of this plant may be harvested and used for dried arrangements.
Forget-Me-Not Myosotis sylvantica	sun, semi-shade	yellow, blue, pink, white	6-12/15-31	May-Aug.	No data	A biennial which will produce a late summer bloom as an annual. If overwintering, it will fill in around spring flowering bulbs.
Flowering Tobacco Nicotiana alata	sun	white, pink, red, green	24-36/61-91	July-Oct.	A-May B-April	Flowers open early in the evening. White flowers emit sweet perfume. Suitable for large bedding. Useless as a cut flower.
Blue Cup Flower Nierembergia hippomanica	semi-shade	lavender, blue, white	6-18/15-46	June-Sept.	B-March	Wonderful for edgings or in rock gardens. Effective in pots or as cut flowers.
Love-in-a-mist Nigella damascena	sun	blue, purple, white	18/46	July-Oct.	A-May	A compact, free-flowering plant with long stems. Very desirable for cutting.
Ornamental Basil Ocimum basilicum	sun	pink, white	15/38	May-Oct.	A-May B-March, April	Variety ‘Dark Opal’ has attractive purple leaves. Very pleasant fragrance. Flowers are relatively inconspicuous.
Corn Poppy Papaver rhoeas	sun	assorted	12-20/31-51	June-July	A-April B-May	Sow seed early where they are to flower. They dislike transplanting. Successive sowings may be made to provide continuous flowering.
Bedding Geranium Pelargonium x hortorum	sun	white, pink, red, rose	12-24/31-61	May-Sept.	B-March	Seed propagated types are more rugged for outdoor use. They are also free of disease.
Penstemon Penstemon gloxinoides	sun	white, purple-red, red	24-48/61-1.2M.	July-Sept.	A-April	Gloxinia-like blooms on tall spikes.
Fountain Grass Pennisetum setaceum	sun	white, pink, purple	40/1M.	July-Sept.	A-May B-March	Excellent grass, several color cultivars in trade.
Common Garden Petunia Petunia x hybrida	sun, semi-shade	assorted	12-18/31-46	June-Oct.	A-May B-April	One of the most outstanding bedding and edging plants. Single, flowering varieties are generally considered best for bedding purposes.
Annual Phlox Phlox drummondii	sun, semi-shade	assorted (no blue)	6-15/15-38	July-Sept.	A-May B-April	One of the easiest annuals to grow. Very well suited for bedding and edging. Mixed colors are very pleasing. Long season of bloom.
Chinese Lantern Physalis alkekengi	sun	red	24-61	Aug.-Sept.	A-May B-April	Red papery capsule is valued for use in dried arrangements. Growth habit of this plant is a spreading vine.
Moss Rose Portulaca grandiflora	sun, semi-shade	red, yellow, white, rose	6/15	June-Sept.	A-May B-April	Will thrive well in the poorest of soil and under dry conditions. Well suited for covering steep banks. Self-sow profusely.
Castor Bean Ricinus communis	sun	green, blue foliage	24-84/61-2.1M.	May-Oct.	A-May	Excellent for large screen plantings. Beans are poisonous. Dwarf varieties are available.
Cone Flower Rudbeckia hirta	sun	yellow	24/61	June-Sept.	A-May B-April	One of the most satisfactory and best keeping annual flowers with a long season of bloom.
Painted Tongue Salpiglossis sinuata	semi-shade	assorted	24/61	No data	B-April	An aristocrat of the annual flower garden if well grown. Requires a rich soil which is well prepared.
Mealy-Cup Sage Salvia farinacea	sun	blue, purple, white	24-36/61-91	July-Oct.	A-May B-March, April	Free-flowering plants which are attractive in borders and small beds.
Scarlet Sage Salvia splendens	sun	scarlet, red, white, pink	18-30/46-76	Aug.-Oct.	A-May B-April March	Bloom freely during late summer and fall. Salvia plants are commonly used for bedding, but for best results they should only be used in limited amounts. The flowers are of no value for cutting. Generally, the shorter the variety, the earlier they will bloom.
Creeping Zinnia Sanvitalia procumbens	sun, semi-shade	yellow	8/20	June-Oct.	A-May	The plants are prostrate in habit and produce flowers much like tiny Zinnias. Very useful for bedding, as they make ideal ground covers. Long season of bloom.
Sweet Scabious Scabiosa atropurpurea	sun, semi-shade	assorted	24/61	July-Oct.	A-May B-April	A very desirable flower for cutting. If faded flowers are removed, the plants will continue to flower throughout the summer.
Dusty Miller ’Diamond’ Senecio cineraria	sun	gray foliage	24/61	May-Oct.	A-May B-March	Excellent for edging in borders and planters. Cultivar ‘Diamond’ is most" often planted selection.
Dusty Miller Sececio viva-viva	sun	gray foliage white flowers	24/61	Apr.-Oct.	A-May B-March	Grown for long, coarse dissected foliage.
African Marigold, American Marigold Tagetes erecta	sun	yellow, orange	12-40/31-1M.	July-Oct.	A-May B-April	Marigolds afford a wealth of color in yellow, orange and bronze. The taller forms are well suited for mass effects and cuttings.
French Marigold Tagetes patula	sun	orange, yellow, bronze	6-12/15-31	June-Oct.	A-May B-April	One of the most useful and colorful of bedding plants. Easy to grow and free of diseases and pests.
Signet Marigold Tagetes tenuifolia	sun	yellow	24/61	July-Oct.	A-May B-April	Good for accent plants. Dissected foliage. ‘Pumila’ group includes various cultivars of low dwarf, compact habit, 1 foot or less.
Jewels of Opar Talinum paniculatum	sun	pink	18/46	July-Sept.	B-March	Tiny flowers on stalks set small red ‘jewel-like’ seed.
Orange Lantern Vine Thunbergia gregorii	sun	orange	Vine	July-Sept.	A-May B-April	A twining vine, readily grown from seed.
Mexico Sunflower Tithonia rotundifolia	sun	orange-red, red	48/1.2M.	July-Sept.	A-May	Stately plant with single, dahlia-like flowers. Excellent for backgrounds or hedges.
Wishbone Flower Bluewings Torenia fournieri	semi-shade	blue, purple	12/31	July-Sept.	A-May C-March	Fine for beds, borders, pots, window boxes and rock gardens.
Blue Lace Flower Trachymene coerulea	semi-shade	blue	24/61	July-Sept.	A-May	Resembles Queen Ann’s Lace which is common along roadsides. Good for cutting.
Garden Nasturtium, Tall Nasturtium Tropaeolum majus	semi-shade	yellow, orange, red	12/31	July-Oct.	A-May	The dwarf flowering sorts are best suited for edging and cut flowers. Climbing varieties may be trellised.
Garden Verbena Verbena x hybrida	sun, semi-shade	blue, red, white	12/31	July-Oct.	A-May B-April, March	Verbenas are free-flowering plants which are well suited for bedding and edging work. Some varieties are well suited as cut flowers.
Viola Viola cornuta	semi-shade	blue, gold, red, apricot	6/15	June-Oct.	B-February	Performs best in cool temperatures and moist soil. Hybrids are more vigorous.
Garden Pansy Viola x wittrockiana	semi-shade	assorted	10/25	May-Aug.	B-March C-Aug.	Sow seed in hotbed in early spring and transplant to garden in May. The best plants are obtained by planting seed in a well prepared cold frame in Aug. and transplanting in special prepared beds in early spring. New hybrids are heat tolerant.
Common Zinnia Zinnia elegans	sun	assorted	6-40/15-1M.	June-Oct.	A-May B-April, March	One of the outstanding bedding and cut-flowers. The small flowering types are especially well suited. Many new hybrids offer a wide selection in flower type and color, and plant height.
Mexican Zinnia, Spreading Zinnia Zinnia haageana	sun	yellow, gold, mahogany	12-18/31-46	June-Oct.	A-May B-March, April	Attractive multicolored flowers. Plants are mildew resistant.