I often exchange gardening columns with Cameron Co. Master Gardener Lori Murray, who writes for the Valley Morning Star. This week, I wanted to share a piece she wrote on Ixora. I’m not a huge fan of Ixora myself because they prefer acid soil, making them high maintenance for our area. However, with their bright, long-lasting blooms I can understand why they are popular. Lori has some great tips to make sure yours look their best.
Ixora, a plant that has become increasingly popular in Valley landscapes, is an ever-blooming shrub actually native to southern Asia. Pronounced “icks-SORE –ah,” the shrub is found in the Rubiadeae family and is closely related to the gardenia and azalea.
The botanical name of the most used Ixora is Ixora coccininea, an evergreen shrub that can be anywhere from 4 to 6 feet tall. Its spread generally exceeds its height and. in warm climates like ours, it’s used for hedges or foundation plantings and can be massed in flower beds. It is popular locally because of its showy yellow or scarlet flower clusters which are produced at the end of the branch and may contain up to 60 small tubular fourpetaled flowers. A single flower cluster can last 6 to 8 weeks!
One source states, “The most important thing to remember when planting Ixora is that it must be planted in acidic soil.” So how can we make sure it does well here in our alkaline soil? By adding great amounts of organic materials and mulch to create the slightly acidic environment required.
Another helpful tip is to fertilize with an acidic fertilizer made for gardenias and azaleas or with fertilizer designed for hibiscus. The ratio should be roughly 4-8-8. It’s also suggested to keep the plant several feet away from concrete or stucco because the runoff tends to make the soil more alkaline; however soil amendments and full sun may balance the runoff. Compost is highly recommended, and so is mulching.
Because it’s a tropical plant, full sun makes Ixora compact and able to produce the maximum number of flower clusters, but the shrub can tolerate partial shade (although it will not produce as many flower clusters.) The USDA hardiness rating for this plant is 9B, which means that we should beware of very cold temperatures. Sources say that temperatures below freezing will cause leaf damage, and a hard freeze will knock this plant to the ground.
Ixora shrubs react well to pruning (even a hard pruning) and should be pruned in winter after flowering. The pruning will bring on new growth in the spring and the plant will bloom on that new growth all summer. It can be pruned back by several inches without harm. Prune each shoot down to just one bud or prune as needed to create the size and shape you desire.
Plant in a sunny raised area, using plenty of planting mix to raise the level of the bed. Dig a hole 1.5 to 2 times wider than the root size but no deeper than the original pot. Rest the root system on the undisturbed soil in the bottom of the hole and fill in around the roots with your prepared bed mixture. Water the new plant with a root stimulator. Once the plant is established, fertilize regularly. Few pests bother Ixora but it is susceptible to aphids and scales. If you start seeing black, sooty mold on the leaves, it’s time to bathe the plant with insecticidal soap. Generous organic mulches will strengthen the plant.
In buying Ixora, look for plants that are very full with multiple branches that will support many blooms. These shrubs should be at least half as wide as they are tall.
Ashley Gregory is the Horticulturalist for Hidalgo County with Texas A& M AgriLife Extension Service.