Many trees, shrubs and wild roadside plants can make good cut flowers.
Forsythia (F. x intermedia)
Forsythia plants are easy to acquire. Buy some from a florist or get a few branches from a friend. Cut into pencil-sized lengths and root in a pot of well-drained soil. They’ll even root in a vase of water. It takes 2-3 years to produce a blooming shrub. Cold weather produces more flower buds, so some years they aren’t much to look at in the Deep South. Prune shrubs hard in spring after blooming to induce additional shoots.
Hydrangeas (H. macrophylla)
Mophead hydrangeas come in many varieties -- some tall, some short. The florist's hydrangeas, which appear potted on shelves around spring holidays, tend to be the more dwarf cultivars and less suitable for cut flowers due to shorter stems. Choose a taller, hardy landscape variety for cut flowers. Hydrangeas root easily from both softwood and hardwood cuttings. Plant 3-5 feet apart in an area that has light or part shade through the day. Bushes can be more floriferous in full sun but will require considerably more water to avoid wilting. Be careful to do any pruning (rarely needed on plants that are being harvested for flowers) after the plants finish blooming, never before. Harvest flowers as the floret color changes to blue or pink from greenish-white. Flowers left uncut at their early peak and harvested later, although still handsome, usually wilt and have poor vase life. For drying, leave them on the bush until petals develop a papery texture. In rainy summers field drying will fail due to the development of reddish brown fungal spots on the petals.
Incredibly, peonies can grow and bloom well in northern Louisiana if properly planted. Roots must be ordered from a reputable peony producer in the fall and planted in October through December after soil temperatures have cooled somewhat. It's very important to plant the 'eyes' (dormant shoot buds) at the soil's surface, uncovered, in amended soil. Plant in sun. They will go dormant and look terribly ratty by summer's end, but just leave them alone, watering occasionally. Give them a few years to get established and they'll produce show-stopping blooms in April. 'Moonstone', 'Festiva Maxima', 'Coral Charm' and 'Fairy Petticoat' are four good starter cultivars.
Willow (Salix spp.)
Corkscrew willow is a large, multi-stemmed shrub or small tree. Cut curly, twisted branches. Water uptake may improve if stems are sliced upward through the center of the stem. Salix caprifolia is the pussy willow. Cut branches as the fuzzy catkins begin to emerge in early spring. Prune annually to increase branch production. All willows are very easy to propagate from cuttings.
Flowering peaches and cherries bloom very early -- usually February and March. Select branches with visible flower buds (round and fat) and cut as the first few buds are opening. Handle with care to avoid knocking off buds. Fruit branches are a good early-season seller at a farmers' market. Citrus branches may also be cut in spring. Intensely fragrant, white flowers add to the attractive glossy foliage.
Beauty berry (Callicarpa spp.)
Berries begin to color in September and will stay on the stem best if cut shortly after taking on color. The U.S. native, Callicarpa americana, produces large magenta berries and also comes in a white form, C. americana var. lactea . C. dichotoma produces many smaller, lavender-colored berries. Prune both in spring to increase branching.
Chinese tallow (Sapium sabiferum)
Chinese tallow is the number one invasive woody plant in Louisiana and should never be planted. Seeds may be collected from the wild in late autumn after the black husks covering the seeds have fallen off. There is a good market for the popcorn-looking seeds on the East Coast, and seeds may also be used for wreath construction for Christmas decorating. Any seed removed from the tree is a seed that will not fall to the ground and turn into a tree, so feel no guilt about harvesting the seed heads.
Curly Dock (Rumex crispus)
This large field weed is used by florists for large arrangements. An early-spring grower, cut it green when seed heads are well developed or wait a little longer until it takes on some burgundy coloration. Worth $6.50 per bunch of 10; not bad for a weed.
In a year with adequate rainfall, solidago is a good fall roadside find. In drought years the foliage is too ugly to sell. It may be grown in the cut-flower plot if regularly divided to control its aggressive nature. Solidago plants ordered from plant suppliers have often been bred for compactness in the ornamental garden and are less useful as a cut flower. There is an intergeneric cross of solidago and aster, called solidaster, that produces magnificent plumes of tiny gold aster flowers and is a wonderful filler.
Eupatorium (E. coelestinum, E. serotinum)
Eupatorium coelestinum (foam flower) is a terrific native that blooms in the fall. It looks much like annual ageratum. It pops up in fields and at the edge of shady areas and is worth cultivating. Combine with goldenrod for LSU purple and gold bouquets. There is another native eupatorium, E. serotinum, that makes large plants with clouds of tiny white flowers that make a good filler. Too large to place in the cut plot, it can be collected from fields and fence rows.
Other roadside flowers
Cat tails, coreopsis, cosmos, grasses, lotus pods. Always do a test for vase life on wildflowers. Cut them and treat them exactly as you treat commercial flowers. Put them in a vase of keeping solution and leave it on your kitchen counter, with the date taped to the vase. Note when the flowers fade or become unattractive. If flowers hold up for a minimum of five days, they can be used as cuts.