Just when you thought you'd put the last bulb of the season in the ground (as they better be), along come the gladiolus. Gladiolus have their own season: They are not planted in the fall, but in winter and spring, the earlier the better if you want to avoid a tiny little critter called a thrips.
Thrips are so small they are almost invisible, but their damage isn't. They thrive in warm weather, and the warmer the weather when gladiolus bloom, the worse the damage. In spring, it may simply be stippled and stripped leaves; in early summer, blotches and freckled flowers; in late summer, flowers may not even open they are so damaged by thrips.
But, plant now or in February, between the rains, and you may never see a thrips, even with a hand lens. Should you run into trouble, you can spray, repeatedly, with Orthene or Diazinon.
Nurseries are well-stocked with gladiolus this weekend, and there is also a once-a-year opportunity to buy bulbs at the Los Angeles County Arboretum in Arcadia (301 N. Baldwin Ave.), at truly bargain prices from gladiolus hobbyists. At the Southern California Gladiolus Society bulb sale on Sunday (9 a.m. to 4:30 p.m.), even the fanciest hybrids are selling for under $2 for a half-dozen bulbs.
At nurseries, or at the sale, you will find several sizes of glads, some called miniatures--but let me warn you that no gladiolus is little, much less miniature. A "miniature" glad grows three to four feet tall, while a normal glad grows to 4 or 5 feet. The first time I planted "miniature" glads, I put them up front in the flower bed because I thought they'd be short. They ended up rising over the flower bed like the Sears Tower over the Illinois prairie.
So what does "miniature" mean? It refers to the size of the flowers, which are somewhat smaller--though still large by any other flower's standards. At the sale, all glads have an identifying number, a number in the 100s or 200s being the smallest and those in the 600s having the largest flowers and generally being the tallest. The rest of the number has to do with color, but sale chairman Henry Wagner assures me that all of that is explained at the sale. There are also photos of most of the varieties being offered plus a handout that tells all about growing glads.
Plant Them Deep
If you've had trouble keeping these large-flowered plants from falling over, you are not alone, but there is a solution--plant them deep. Gladiolus growers suggest planting the large bulbs 6 inches deep and the "miniature" bulbs three inches deep. This is deeper than you'll see recommended in gardening books, but you will not need to stake the flowers. One of those handy bulb planters that look like oversize cookie cutters is helpful here.
It is not necessary to add fertilizer to the planting hole. I was surprised that even gladiolus enthusiasts--who regularly enter their flowers in shows--barely fertilize. They don't consider it that important, fertilizing very lightly only after the plants are about a foot tall, and then again as the buds form.
They do consider watering extremely important and suggest an inch of water every week. That translates into about two waterings per week, letting the sprinklers run for 20 minutes, at least in my garden.
Space the regular glads 6 inches apart and the smaller ones only 4 inches apart, and don't plant them all at once. Unlike most bulbs, gladiolus bloom about 2 1/2 months after planting, no matter when you plant them, so if you stagger the plantings--putting in some now, some two weeks later, and so on--you'll spread out the harvest of flowers.