Gladiolas are heralded by gardeners for their contribution of tall funnel-shaped blooms adding splashes of color to yards. You can purchase bulbs that will bloom creamy white, peach, red, violet and pink flowers to set against your green expanse. Their corms or bulbs should be planted according to their size in full sunlight and well-draining soil. Start planting at the end of May for an array of fall flowers.
Conduct a soil pH test on your planting site to be sure that it is in the proper range for growing gladiolas. Gladiolas grow in an acidic soil with a range between pH 6.5 to 7.0. Purchase a pH testing kit from you local county extension office or gardening supply store. Dig a 6-inch hole and collect soil samples. Mail the samples to the laboratory's address provided on the testing kit and wait for the results. Add lime to soil that is too acidic or sulfur to alkaline soil. Arrange your gladiola bulbs according to their size, which will determine what depths to plant your bulbs.
Planting Gladiola Bulbs
Measure each on of your bulbs and place them in small, medium and large piles. Small bulbs are a half an inch in diameter or less. Medium bulbs are up to an inch in diameter and large bulbs are an inch and a fourth in diameter or larger.
Dig an 8-inch hole in your planting site to accommodate the depth that your larger bulbs need to be planted. Place your larger bulbs with their growing tips facing upward. Make sure that they are in groups of five. Space them 6 to 8 inches apart. Rows of gladiolas should be 20 to 36 inches apart. Spread a layer of soil on the top of the bulbs. Plant your next group of medium bulbs in a depth of four inches. Cover with soil. Your last set of five small bulbs should be at a depth of 3 inches deep. Pack the soil over the bulbs and insulate them with a 2-inch layer of mulch to lock in the moisture. Water the area thoroughly.
Gladiolas should be given at least an inch of water weekly, which is .62 gallons every square foot. Monitor your plants for common gladiola pests like thrips. Thrips are slender-winged insects that suck the cells of flowers and leaves. Spray them with an insecticide soap if you see any signs of them or their damage. Look for discolored plants and specks of insect feces. Dig up your gladiola bulbs after the first frost and store them in a cool place over the winter. Inspect each one for fungus diseases or pest damage.