Prepare soil for perennial plantings with lots of organic matter and good drainage. They will be in the ground for years and should be separated from annual plantings to avoid excessive disturbance.
Alstromoeria (A. psittacina)
The greenhouse varieties of alstro don’t often survive with the high rainfall in South Louisiana. There is a garden alstromoeria, the parrot or Peruvian lily, which blooms in May. There is no market for this one for florist sales, but it is just as good as the cut-flower hybrids for bouquet work or as a bunch for the farmers' market. It’s got a lovely cluster of red and green flowers and needs to be grown in a contained area because the rhizomes are highly invasive. Harvest when the first flower opens. Like all alstros, stems are not cut but rather yanked straight up out of the plant. Shorten it to a useful length. Alstroemeria’s great popularity as a cut flower is due to the fact that every single bud will open, no matter how small when cut. Never sold because of its invasive nature, acquire the rhizomes of A. psittacina from a friend. Another garden alstro that has proven to do well on the Gulf Coast is called Sweet Laura. Also blooming in May, it provides a yellow for bouquet work.
Aster (Aster spp.)
Like many perennials, most of the asters are not terribly long-lived in our climate; three to five years is typical. Asters naturally bloom in the fall. These frequently surprise the grower with late-spring or summer blooms, but spring stems tend to be shorter than the fall stems. One of the most popular is probably Monte Casino (A. ericoides), which produces multi-branched stems with clouds of small white, gold-centered flowers. Individual branches may be large enough to cut from the main stem. The A. nova-belgii varieties like Blue Gown have a larger flower in clear blue, rose or white but don’t produce as reliably as the more delicate Monte Casino. All are terrific fillers for bouquet work. See that they have adequate water throughout the year, or the foliage will have crisped edges and flowering will be reduced. Cuttings are required for propagation.
Balloon Flower (Platycodon grandiflora)
Seed-grown plants must be grown for 2-3 years before the plants produce stems good enough to cut. First-year stems are short and curl on the ground, but as the fleshy root increases in size with time, so do the strength, length and bud count of the stems. Gallon-size plants are available from mail-order perennial producers and perform well the first year. Balloon flowers come in a clear blue and white. Pink is advertised, but it’s really white with a few pink veins. The flower gets it’s name from the fact that buds start out as big puffed up balls (like balloons) that literally pop open into a large bell shape. Balloon flower can be kept in continuous summer bloom with dead-heading or cutting. Sentimental Blue is a good variety and easy to grow from seed.
Black-eyed Susan (Rudbeckia spp.)
The garden variety R. fulgida Goldsturm makes a good cut. Cut the entire stem with buds. Expect some rebloom for a later cutting. One of the best of the black-eyed Susans is R. hirta Indian Summer. Start from seed or transplants in the fall. Plants make a large (1- to 1½-ft.-wide) fuzzy rosette of leaves that produces huge, magnificent flowers in mid-summer. Cut to the first joint of the branching stem. They will bloom for almost 6 weeks and can be extended with succession planting. While listed as a perennial in some sources, R. hirta rarely survives to the next year. Sell them at farmers' markets bunched, in bouquets and in tandem with sunflowers as a bouquet stretcher. They provide a lot of gold, and if the customer mixes their few expensive sunflowers in with them, they make a bowl full of Summer.
Gerbera Daisy (G. jamesonii)
Gerberas can be a fantastic crop, but their success is highly dependent on two factors: cultivar and exposure. They require sun in the winter and shade in the summer. With the proper exposure and frost protection, gerberas can produce year round except for the very hottest part of summer. They are well grown in an unheated greenhouse in ground beds. In freezing weather, close up the house and roll an insulating row cover over the rows. The cover will bend the stems, but they will straighten back up after the cover is removed. For really low temps add a small electric heater to keep the air above freezing. If the grower fails to keep temperatures above freezing, gerberas will freeze to the ground and go dormant until spring. To achieve the desired light exposure, shade cloth should be stretched over the top of the house in the summer. The same exposure could be achieved under high deciduous trees. With proper conditions, gerberas will produce heavily most of the year, with a light crop during high summer temps. Cultivar selection is crucial, but unfortunately there are no selection guidelines for our climate. In a trial of a dozen tissue cultured c.v.’s from California, all but four died immediately from presumed fungal disease, possibly root rot. The four survivors, Visa (red), Pacific (yellow), Joker (yellow/orange) and one other red variety thrived and produced 50 - 100 stems every week from a bed 8' X 80'. Terra Nigra is the major producer of virus-indexed plants, sometimes brokering through larger suppliers of cut-flower materials. Plant on one-foot centers in spring. Fall-planted plants tend to sit until the days lengthen again. Gerberas are harvested when completely open and the face has flattened out. Close observation shows that the row of disk flowers next to the petals (ray flowers) is open when they're ready to cut. Stems are not actually cut, because cut stubs are too likely to allow the entrance of pathogens. Instead, bend the stem backwards, forwards, sideways until it pulls loose. Don’t tug, or part of the crown may come with the stem. Cut the ends of the detached flower stems and place into a tall bucket of keeping solution with a cover fashioned from hardware cloth. The stems fit down through the holes and hang in the water, with the flowers laying flat on the mesh. To maximize water uptake, leave the bucket at room temperature for at least an hour before placing in the cooler. Slugs love gerberas, but beer traps work well. There are a few leaf spot diseases that may require fungicide treatment at some times of the year.
The commonly seen garden leatherleaf is the same one the florists use. Plants require two years to become well established. Provide full or dappled shade by either growing under trees or stretching shade cloth over frames. Clean out old damaged leaves in the spring. Cut stems all the way down to the base of the plant. Don’t ever cut all of the stems, since some are needed to provide nourishment for the root system.
Phlox (Phlox spp.)
Fancy garden phlox don’t grow on the Gulf Coast because our high humidity is too conducive to the fungal diseases that may attack them. Phlox pilosa is a 15"-tall species phlox with a lovely pink cluster of individual flowers in March and April. As a U.S. native, it has absolutely no problems. It’s such a good spreader that you can cut the flower stems all the way to the base without depleting the plant stand’s health. There is a form of Phlox paniculata (the fancy garden phlox) that is an old Southern garden plant with summer-blooming magenta flowers. It is also problem-free and as fine as the fancy garden phlox if you can stand the color. Both of these phlox will be difficult to find, but ask gardening friends for starts. The white Carolina phlox, slightly shorter than garden phlox, also performs well and reblooms in the summer. All are good for bouquets.
Physostegia or Obedience (Physostegia viginiana)
A rapidly reproducing perennial, physostegia makes a good spike flower for late summer. Flowers come in rose or white. The white is shorter, less rampant and less floriferous. The rose variety tends to flop over and should be cut back in early summer to produce shorter, sturdier stems. Thin the planting, yanking out all of the thin stems early in the season. Divide every other year for best performance. Toss the plants or sell them; there will be plenty more. Its greatest value is that it is one of the very few spike flowers that will produce in the dog days of summer.
Purple Cone Flower (Echinacea purpurea)
Coneflower is a prairie plant, so it needs to be planted in a well-drained row. Once well established, a long-stemmed variety like The King produces enough good strong stems to make it worthwhile. The newer Sunset series produces in various orange hues,and flowers are sturdy and long-stemmed. Cut as soon as the flower is fully developed.
Red Hot Poker (Tritoma or Kniphofia)
Red hot poker makes a large plant that produces 3'-all, outrageous-looking pastel spikes the second year after seeding. Full-sized transplants may not all bloom the first year but are reliable after that. Blooms in April and May. The enormous flowers should be cut as soon as the bottom florets begin to open. Florists use stems in men’s arrangements,but it’s a hard sell at a farmers' market. It fascinates shoppers, however, and may get people to stop who wouldn’t stop normally. As it ages in the vase, it begins to twist a little and drops pollen and nectar on the table. Available also in a good, clear, solid-yellow form.
Statice (Limonium sinensis, L. sinuatum)
Lace veil statice is a good, hardy perennial that can be started by seed and takes two years to begin producing flowers. The third and fourth years, plants are very productive, making 5-10 stems per plant. Stems are long and branched with tiny yellow and white flowers in the spring. Use as a filler instead of baby’s breath, which struggles on the Gulf Coast. Airy, filler-type flowers like these are usually sold by volume rather than stem count. Bunch enough to make a bunch 1-1½“ wide at the bottom. L. sinuatum, the standard florists statice, is a good winter annual crop. Start with plugs in the fall. They produce well through the spring until they get shut down by summer heat.
Salvia (S. farinacea)
Of the hundreds of salvias, the tall, spike-forming Salvia farinacea is the best. It is easy to grow from seed or cuttings and Blue Bedder is the tallest and best-suited to cut flower production. Cut using the rules for branching plants, always leaving a few more sets of leaves for new shoots to come from. The constant cutting keeps them in bloom all summer. Any unsold flowers can have the heads snapped off for drying. Dried flowers look very much like lavender; scentless but holding their color extremely well. Short-lived perennials, individual plants survive 2-3 years. Several other large-flowered salvias have cut-flower uses, particularly Indigo Spires. Other salvias, unlike S. farinacea, are seasonal bloomers, producing mostly in late summer and fall.
Sweet William (Dianthus barbatus or D. hollandia)
Sweet William is a biennial, meaning that you must plant the plants in the previous fall, get winter vernalization and cut flowers in the spring from a plant that will subsequently die after bloom. Look for varieties recommended for cut-flower production to get the stem length. A good length would be 12"-15". Hollandia is a hybrid of D. barbatus that does not require vernalization and has longer, straighter stems (18"-20"). Flower colors range throughout the reds and have the characteristic dianthus scent. Try some of the lovely annual species of dianthus that grow well in the cool season, with fringed flowers and pretty good stem length. Many will perennialize. The most famous florist's dianthus, carnations, will not grow here due to disease problems and lack of heat tolerance.
Tansy (Tanacetum vulgaris)
Native to the western United States, tansy is short-lived on the Gulf Coast but well worth replanting. The big head full of gold buttons stands on a three-foot stem and is tough as nails. It’s a great dried flower, too. Tansy may also be sold as an herb.
Veronica (V. longifolia)
While they take a few years to build a sturdy plant from seed, veronicas can be cut continuously and kept in production from late spring through the summer. Only longifolia cultivars of veronica produce stems of sufficient length. Flowers are a true blue spike and add a lot to a mixed bouquet. Cut when the florets first open at the bottom of the flower.
Yarrow (Achillea millefolium, A. filipendulina)
The common white A. millefolium (fernleaf yarrow) is the most-reliable perennial. The hybrid mixes may not return reliably in following years. As with gerberas, the grower must trial a hundred to find the few that have the disease resistance needed to perennialize. Most of the plants will not bloom the first year from seed, though those that survive longer will give 6-10 stems per plant. Yarrow is also unreliable in another way. Sometimes stems wilt regardless of the proper post-harvest care. Leave them in the bucket at room temperature so the wilters can be culled before sale. Yarrow may also have a rather short vaselife, only 4 days or so. A. filipendulina, with large, flat, gold heads, is sometimes seen in Southern gardens. Beg a piece from a gardener and start building up your stocks. Parker’s and Gold Plate, the two commercially available varieties, do not survive our hot, moist summers.