First, flowers for a wedding ought to be bright, fun, cheerful, festive flowers. For example, I like “glads,” gladiolas, but I see them used at funerals all too often, so they seem out of place at a fun affair like a wedding.
The one thing you don’t want with wedding flowers is pollen! With wedding flowers very little pollen is good, and no pollen at all is by far the best.
Daises: For starters I would avoid using most of the daisy-related type flowers, daisies, gerbera, chrysanthemums, asters, dahlias, and sunflowers unless you know they're pollen-free ones. There actually are quite a few chrysanthemums, dahlias and asters that are called formal doubles and that have no pollen. All of these formal doubled flowers will be ones with a very high number of petals per flower. What has happened with these flowers is that they have been hybridized so often that the pollen parts (the stamens) have turned into parts that now look more like petals (staminoids). All true formal double flowers will be pollen free.
Goldenrod flowers (bright yellow) are often used as fillers in arrangements and goldenrod is a daisy-ragweed relative and will shed plenty of allergenic pollen. Don’t use goldenrod!
Baby’s breath is a popular wedding flower, again, often used as filler between other larger flowers. Baby’s breath is grown and sold as single or double flowered. If you use baby's breath, use only the doubled flowered types.
Roses: Florist type hybrid tea roses that are still in a closed bud stage and that are not especially fragrant are excellent choices and will shed no pollen. If using roses picked from the garden, choose only those roses with healthy green leaves, and pick roses that are still in the bud to half-open stages. Some free-flowering garden roses, such as the beautiful pale pink ‘Cecile Brunner’ roses, are always allergy-free and produce no pollen at all. The Banksia roses, which will be either yellow or white, are small, cute, come in dense sprays, and are also pollen free.
Pots of blooming hydrangeas, especially of the old-fashioned Hydrangea macrophylla type, are mostly pollen-free and are good choices to use. Pots of blooming double tuberous begonias, especially all the erect type cultivars, almost all of these are great, very large, colorful flowers and pollen-free. The fancy flowered begonias called ‘Reigers’ begonias are also pollen free and come in bright colors or white, yellow, red, salmon, and pink.
Lilies of all types can often now be purchased that are either simply pollen-free flowers, or else someone (who doesn't have allergies), can carefully remove the brown pollen-bearing anthers on the tip of each of the six stamens in each regular lily.... watch this pollen as it will also easily stain your wedding clothes, especially anything white. Lilies that have had the anthers removed will be completely pollen free. ** A caution here though: sap from any and all kinds of lilies can cause a very nasty, long-lasting itchy skin rash…certainly nothing any bride would want on her honeymoon! With this in mind, watch out for the sap of all lilies and of Alstromeria too. Also, it would not be a good idea for a bride to even carry a bouquet of lilies, certainly not if she has skin that is in the least bit sensitive. Anyone helping with the wedding would be wise not to stick their hands into the water in which the lilies have been standing, as this water will have the sap in it.
Camellias: Camellias come in bright white, red, or pink colors and few flowers are more beautiful than nice camellias, however they are not easy to buy from florists. Still, a gardener friend may have some you could use if the season is right…spring and fall. If you can find them, there are many nice fully doubled, formal double type camellias that are pollen-free. These camellias will look fabulous floating in small bowls of water on tables.
Orchids: Very few orchids cause any pollen allergies and it is now possible to buy small pots of beautiful blooming orchids at quite reasonable prices. Occasionally there is some skin rash associated with orchids, so watch any and all sap from cut flowers. Individual orchids should have their stems in small tubes of water.
Although certainly not indoor plants, pots of growing pansy, viola, and impatiens also can look terrific and they are all very low allergy potential flowering plants. In California or Florida it might be possible to get large sprays of bougainvillea flowers. These now come in many colors, including bright white. Double bougainvillea flowers will have no pollen at all, and even the more typical types of bougainvillea will shed next to no pollen. Bougainvillea flowers are good too for using around perfume sensitive people, as they have next to no smell.
Lawns: If the wedding is to be held on a lawn, or if the reception afterwards is, I'd suggest that the lawn be mowed two to three days ahead of time, and that a lawn mower with a really good grass catcher be used.