There is nothing like growing our own; whether vegetables, fruit or cut flowers. Most fruit and vegetables are grown to be eaten, so are not missed too much when harvested. Even colorful citrus fruit is better harvested than left out in the garden. No one wants to waste it. Flowers are not so simple. They are so colorful and fragrant in the garden, that it is tempting to leave them all out there.
Cosmos and many kinds of daisies are so abundant that there are plenty for both the home and garden. Gladiolus are not so fortunate. They bloom only once. Cutting the flowers to bring into the home deprives the garden of their color. What is worse is that cut gladiolus, although excellent cut flowers, do not last quite as long as they would in the garden. Roses at least continue to bloom.
Daylily can be a good cut flower, but individual flowers last only a day (obviously). This is not a problem in the garden because new flowers bloom daily to replace those that that have finished. Cutting stems not only takes flowers in bloom, but also takes the flower buds behind them that are waiting for their turn to bloom. However, not many, if any, of the unbloomed buds bloom once cut.
Many types of iris, except for Dutch iris, have the same problem. Attentive garden enthusiasts might leave iris to bloom in the garden, and might even groom fading blooms from fresh blooms on the same stems, and then cut stems to bring into the home when the last bud on each stem is just beginning to bloom. The last flowers are not as excellent as the first, but it is a fair compromise.
Cannas are not so functional. They are great in the garden for both flowers and foliage, but fade too soon in the home. Bougainvillea and crape myrtle stems likewise start to wilt and drop flowers immediately after getting cut, but for those who do not mind cleaning up after them, there are plenty of papery flowers to last a few days. The wilted tips of bougainvillea stems can be pruned out.
There are no rules to cut flowers. Lily-of-the-nile might seem like a silly choice, but works quite nicely for those who dare to try it. New Zealand flax flowers are not very colorful, but provide striking form. Zonal geranium and nasturtium work well with or without foliage attached. Lemon bottlebrush, photinia, New Zealand tea tree, bugle lily, various hebes, and all sorts of salvias are worth a try.