1. Soil and pH Needs
Though they will perform best in moist soils, Gaillardias are highly drought tolerant. Do not enrich the soil with compost or other rich ingredients when planting. It does best in poor, loose soils and does not tolerate heavy clay. Heavy clay soils will retard root growth and starve the plant of oxygen, which can lead to root diseases. Soil pH should be 5.5 - 6.5 for optimum growth; and should be tested prior to planting but after adding any amendments. This can be done quite easily with a portable pH tester. Mix one part soil with two parts distilled water, stir well and wait thirty minutes, then follow the instructions for using the pH meter. If pH is too low, the addition of lime is warranted. However, the rate will vary depending on how much you need to raise the pH and the type of soil you are dealing with. Clay soils or those with a lot of organic material have a high buffer capacity and require more lime than sandy soils, which have a low buffering capacity. A good soil testing lab can determine the lime requirement index (LRI) of your particular soil and can recommend types and rates of lime to use. When watering, try to soak the soil thoroughly, but do not water so freely that puddles collect on the ground. Avoid getting moisture on the leaves which can cause diseases to occur. Water early in the day so foliage that gets wet can dry out before evening. A 2 or 3 inch layer of mulch spread on the soil discourages weeds. This mulch also helps prevent evaporation of moisture from the soil and it harbors beneficial organisms to help protect plants from pest problems. The mulch will decompose over the season, adding valuable organic matter and some nutrients to the soil.
Gaillardias aren’t heavy feeders in the landscape; and can have a crop life through the summer until first frost. An application of a balanced controlled-release fertilizer (CRF) such as 10-10-10 or 14-14-14 with a 3-4 month formulation applied to the bed at planting will keep the plants well fed, depending on the amount of irrigation applied and the average daily temperature. In areas of high irrigation and high temperatures it may be better to use a formulation with a slower release rate since higher temperatures will cause the fertilizer to be released quickly. Do not over fertilizer. Too much nitrogen will promote excessive foliage growth at the expense of flower production.
Gaillardias are prone to several diseases in the landscape. Problems such as white smut, Thielaviopsis/Rhizoctonia, and powdery mildew commonly are the result of overhead irrigation, improper plant spacing, poor air circulation, and watering too late in the day. These diseases can be avoided by employing proper cultural practices. White smut will first show as light green spots, and some will have tan centers. These will form on the leaves and eventually white spores will form on these spots. The leaf spots will later become dark brown. Thielaviopsis and Rhizoctonia are root and stem rots that cause the lower stems to turn tan to dark brown. Sometimes, white webs of fungal growth can be seen growing in these areas. A plant with powdery mildew will have white fungal growth on the upper surface of the leaves and may also form on the flower petals.
Aphids and thrips commonly attack Gaillardia. Aphids feed on the plant sap. This halts growth, causing the leaves to become deformed. Aphids also excrete honeydew which causes sooty mold to develop and makes the plant unsightly. Thrips cause damage to the plant by piercing and sucking cells on the leaf surface. This causes silver-grey spots to form on the foliage. At high infection rates, the leaves may wither. A healthy, vigorous plant is less susceptible to pest damage than unhealthy plants.
5. Tips for Success
- Gaillardias prefer full sun, and drought conditions are tolerated once established.
- Gaillardias are deer resistant in the landscape.
- Pinch off spent Gaillardia flowers (dead head) to encourage continuous blooming and maintain a neat appearance.
- Remove weeds from the plantings that compete with Gaillardia for moisture, nutrients and light.
Information provided by Syngenta Flowers