The most common reason for red leaves on a geranium is cool temperatures. Disinfect tools after use. Geraniums that are planted too close together also tend to develop red leaves. I have tried just about everything, including all sorts of fungus and disease sprays. The symptoms are mainly red to brown lesions or rings on the underside of foliage and powdery red to brown pores covering the underside of foliage as the disease progresses. Leaves turning reddish purple in color is most often seen in corn crops. In autumn, geraniums with red leaves can be left for added fall color. Diagnosing the problem requires examining your geranium's care, and adjusting your regimen accordingly. â¦ Red geranium leaves signal the plant is stressed in some way. Geranium Leaves Turning Red. If your geranium's foliage turns red, a few simple fixes can get the problem under control. As a result, the leaves of the geranium turn red. Feeding causes brownish, round sunken spots on leaves Nymphs are red or red and black; adults are greenish yellow with 4 black stripes, ¼ to 1/3 inch long More information on Four-Lined Plant Bugs When placed in sites where light is too strong, geranium leaves turn red as a defense. Also, darker green leaf cultivars will display less leaf yellowing than lighter green leaf cultivars. This is a physiological condition that is call oedema (uh-DEEM-a) and is caused by cells in the leaves that burst because the plant takes up too much moisture without transpiring. If this pressure inside the geranium plant is great enough, it can cause the cells to rupture, creating scab-like wounds. Jul 19, 2015 - Geraniums are among the most popular bedding plants. I had posted the same question in a facebook group based in Bangalore India (where I'm, from) and was surprised when â¦ Hi, came across your comment while scouring the net for answers as to why my pelargonium leaves (of all 5 plants) were turning pale and white. Pelargoniums that are planted too close together also tend to develop red leaves. A fungal disease known as geranium leaf rust can cause red or brown lesions to form on the undersides of geranium leaves. Find more gardening information on Gardening Know How: Keep up to date with all that's happening in and around the garden. Geraniums are sun-loving flowers, but also plants that love â¦ The leaves turn yellow, then curl up to a crisp brown. This may be because the plant is receiving too much water or too much sunshine, or has been planted outdoors too early or in mineral-deficient soil. Phosphorus-deficient plants mature slowly, showing stunted growth and fewer flowers and fruit. Itâs best to water geraniums when they needit and the simple way to know that is with a finger test. The most common reason for red leaves on a geranium is cool temperatures. Youâll tend to notice this if youâregrowing your geraniums outdoors in full sun and get several inches of rainfallduring the spring or occasionally in the summer months too. Ralstonia solanacearum: Purchase culture-indexed plants. When placed in sites where light is too strong, geranium leaves turn red as a defense. Geraniums thrive when they're contained in pots. However, geranium leaves turning red can also signify more serious issues. Remove and discard infected plants, or cut away affected plant parts with a clean, sharp knife or razor blade. Sign up to get all the latest gardening tips! When summer approaches, garden centers brim with colorful geraniums (Pelargonium spp.) While the bright red coloration of stressed geraniums can actually be quite attractive, it is a sign for concern. Learn which plants thrive in your Hardiness Zone with our new interactive map! Lack of magnesium or phosphorus can also cause red leaves on a geranium. One of the most common reasons the leaves of a Geranium plant curl is because of an aphid infestation. Geranium plants have low water needs and red geranium leaves oftentimes are caused by overwatering. A fungal disease, blackleg (Pythium spp.) According to Gardening Know How, geranium leaves turn red when the plants are stressed. Some of my geraniums accumulate a very small, black granular/tubular type of substance on the leaves. Geraniums or Pelagoriums. Overwatering. I saved 4 annual geraniums over the winter. This disease is caused by the fungus Puccinia pelargonium-zonalis. This problem occurs early in the season, often due to cold and wet soil. This may be because the plant is receiving too much water or too much sunshine, or has been planted outdoors too early or in mineral-deficient soil. Photo: CriticallyChallenged, reddit.com. Red leaves are often caused by geraniums receiving too much water. Not mine. The oldest leaves are affected first. Yellow and Curled Brown Leaves on Perennial Geranium. Potted geraniums often suffer from sitting in full saucers and getting waterlogged. Understanding the Warnings. Plants that have been grown indoors from seed or as cuttings should be exposed to colder outdoor conditions gradually. Red leaves are often caused by geraniums receiving too much water. Only â¦ When soil lacks sufficient phosphorus, sugars build up and red pigments develop in some plants. The leaves on geraniums turn yellow whenthey get too much to drink. It is nothing to do with watering unless the plants are very dry at the roots - not likely as you are tending to them. Continue reading to learn more about afflictions that can lead to red leaves on geraniums. Another deficiency that can cause red leaves on a geranium is low pH. Do not bring ground-planted geraniums into the production area or propagate from them. Plan the perfect garden with our interactive tool →, The Gardener's Network: How to Grow Geraniums, When summer approaches, garden centers brim with colorful geraniums (Pelargonium spp.). Ivy geraniums, for example, typically display brown, corky lesions on the undersides of the leaves. It lives in the soil and enters the plant by its roots, resulting in yellow, red, and brown leaves on your geranium as the plant dies. Why Do Geranium Leaves Curl? My plant has been doing fine, and blooming, but suddenly the lower leaves are slowly turning brown on the edges, and then the entire leaf turns brown. If you have ruled out temperature, watering or fertilizing issues as a cause for red leaves, it may be a good idea to test your soil pH. I notice it about every 2-3 days. Fast-growing geraniums have small root systems that are vulnerable to deficiencies of phosphorus and trace minerals. The ideal pH for geraniums is 6.5. Corn with a phosphorus deficiency will have narrow, bluish green leaves that eventually turn reddish purple. Leaves Turning Reddish Purple in Color. Why Are My Geranium Leaves Turning Red? Geraniums grow quickly, flower profusely and delight seasoned and beginning gardeners.