In containers, allow the top of the soil to dry before watering again. and stink with rot. This site is maintained by Center for Agriculture, Food and the Environment in the College of Natural Sciences. Be careful not to over-fertilize; follow the directions on the label of the plant food closely. Discard infected plants and remove plant debris and infested soil. When stem rot is present, fungicide must contact the stems for effective control. The compact leaves are oval-shaped and a bit sticky. Some varieties of Million Bell hanging baskets tend to get flat on top – a phenomenon we call that ‘balding’ – and they need to be pinched back regularly. Fungicide applications will not cure affected plants, but will prevent infection of healthy plants. Source: Premier Tech Horticulture" Calibrachoa are susceptible to these pathogens at any stage, but are particularly vulnerable when they are young. Thereafter, place plants in a slightly cooler location. You can also try a soilless potting mix. This will prevent buildup of mineral salts. The Spruce uses cookies to provide you with a great user experience. Set the pot under bright light, and keep the cuttings moist and warm (about 70 degrees Fahrenheit). Practice good sanitation, starting with clean growing media, pots, flats, and plant material. This photo shows a progression of plants that have been infected with Thielviopsis basicola, root rot, often called Black rot. Place containers where temperatures are consistently 70 degrees Fahrenheit (21 C.) for the first two weeks. Root rot or mold infection can set in if these plants are overwatered. Calibrachoa are usually easiest to grow in containers. Prevention in the form of good air circulation, proper water management, and good soil porosity is the best defense. It also works well in unusual containers, such as colanders or even plastic laundry baskets. Practice good sanitation, starting with clean growing media, pots, flats, and plant material. To check if your plant needs water, stick your finger into the soil up to the second knuckle. These plants bloom best with at least six hours of full sun, but they can tolerate partial shade—especially in warmer areas, where plants that get some shade are likelier to survive into the summer months. Some varieties of Million Bell hanging baskets tend to get flat on top – a phenomenon we call that ‘balding’ – and they need to be pinched back regularly. The plant on the left is healthy, the middle plant showing blackened roots and plant on the right with roots completely dead. The leaves may also become distorted (smaller than usual, twisted, etc.). Thielaviopsis is favored by alkaline pH and can be managed by keeping the pH of the media at 5.5. Calibrachoa is a prolific bloomer and produces 1-inch blossoms that resemble tiny petunias. Add water only after the top inch or so of the soil dries out. In most growing zones, million bells is best planted or repotted in spring and can bloom continuously through the growing season, and its flowers attract butterflies and hummingbirds. Calibrachoa - Root rot (thielaviopsis) vs Healthy root. Root rot can be identified by the presence of soft, brown roots. But when soil is soggy, fungal spores multiply and the fungus starts to spread 3, developing in the extremities of the roots first. The plant on the left is healthy, the middle plant showing blackened roots and plant on the right with roots completely dead. Kerry Michaels is a writer and photographer with several years specializing in gardening and landscape design. Resources from UMass Extension and the Center for Agriculture, Food and the Environment: ag.umass.edu/coronavirus. Million bells plants have simple demands: They require sunlight, enough water, and food. Don’t water again until the soil dries out again. Drench the soil with Cleary's 3336,Fungo Flo, Contrast, Medallion, or Terraguard. Then calibrachoa can be grown cooler as they have an established …