Summer flowering bulbs provide an excellent way to introduce color and interest into the summer landscape. Most summer flowering bulbs are native to tropical or subtropical climates and will reliably bloom here for many years. Indeed, for some of these plants, the trick is not getting them to grow, but keeping them under control. Summer flowering bulbs are generally planted in April and May, although plants growing in pots can be planted through the summer.
These plants fill a wide variety of uses in the landscape, providing valuable additions to flower beds, perennial borders, ground covers and containers. There are summer bulbs adapted to just about every growing condition in your landscape, from sun to shade and well-drained beds to boggy areas. Think of them as long-lived herbaceous perennials that will contribute flowers and/or foliage to the area where they are planted for many years.
Summer bulbs will grow more vigorously if you prepare the planting bed properly and fertilize them occasionally. You should generally dig generous amounts of organic matter, such as compost, aged manure or peat moss, into the area before you plant your bulbs. A light sprinkling of a general-purpose fertilizer should be incorporated along with the organic matter.
For existing summer bulb plantings, fertilizing in April and again in July with a general-purpose granular fertilizer is quite sufficient. You may have found that some of your summer bulbs have grown vigorously in the past without fertilization (perhaps even more vigorously than you anticipated or desired). Under those circumstances you do not need to, and probably shouldn’t, fertilize them.
These summer bulbs thrive in Louisiana:
Full sun to part sun:
Agapanthus, Belamcanda, Bulbine Calla, Canna, Crinum, Crocosmia, Dietes, Garlic Chives (Allium tuberosum), Gladiolus, Gloriosa Lily, Habranthus, Hymenocallis, Iris, Lilies, Oxalis, Scilla peruvi- ana, Stargrass (Hypoxis angustifolia), Tigridia, Society Garlic (Tulbaghia), Zephyranthes.
Part shade to shade:
Achimenes, Alpinia, Arisaema, Bletilla, Caladium, Calla, Costus, Curcuma, Globba, Hedychium, Hymenocallis, Kaempferia, Walking Iris (south La.), Oxalis.
The LSU AgCenter and the LSU College of Agriculture