Why Did My Gladiolus Flowers Grow Backwards?

Flowers

• When planting gladiolus corms, there is no way to predict what direction the single or double row of flowers will face once the plants bloom. If this is a worry, plant gladioli where you can view the flowers from many directions, create a mass planting of gladioli or plant them in containers and turn the containers to better show off the flowers. Plant varieties that produce a double row of flowers, as the flowers on these spikes are visible from several directions, or plant corms sized Jumbo 1, 2 or 3, as they are more likely to produce multiple spikes. Remove any flower spikes facing the wrong way for use as cut flowers.

Planting

• Plant the corms with the pointed end facing up, toward the top of your planting hole. Make sure that the corms do not flip over as you fill the holes. Do not plant corms on their sides or upside down. Select a site that offers full sun for the best display, and your reward will include large spikes and more vividly colored flowers. Plant your corms during the months of May or June.

Disease

• The disease aster yellows, caused by phytoplasma organisms spread by leafhoppers, causes distorted flower spikes in gladioli. Insecticides are not recommended to address leafhoppers, and affected plants must be destroyed, according to the Colorado State University Cooperative Extension.

Pests

• Thrips damage flower buds before they open, causing malformed flowers. The University of Minnesota Extension suggests thrips are best controlled by treating your corms at the time you store them by dusting them with carbaryl and then storing them at temperatures between 35 to 40 degrees Fahrenheit. The Extension suggests treating growing plants with carbaryl when you initially find damage from thrips.

Damage

• Select and plant only undamaged, high quality corms. Damaged corms are vulnerable to disease and are likely to produce stressed or inferior plants. Corms should have firm flesh and no discoloration. Look for wide corms with a thick midsection and a shape similar to a bulb of garlic. The North Dakota State University Extension warns that corms smaller than an inch may not flower their first season.