I have had creeping phlox planted for 6-7 years and for the last couple years there has been so much dead stuff in it that I am tempted to dig it all up. With large flowers that are red, pink, blue or white, the perennial is hardy in U.S. Department of Agriculture plant hardiness zones 2 through 9. Spray stubborn infestations with a pyrethrin/pyrethrum insecticide according to label instructions. Garden phlox (Phlox spp.) Just like the name implies, powdery mildew symptoms include a white, powdery substance appearing on the tops of leaves. Now the leaves are turning brown. The tips are deformed. Garden phlox is a simple-to-care-for plant, and proper cultural practices can prevent problems that cause brown spots on its foliage and a lack of vigor. Chemical control is rarely needed when brown spots mar phlox's ornamental quality. BushDoctor Certified GKH Gardening Expert. https://www.gardeningknowhow.com/plant-problems/environmental/learn-how-to-avoid-and-repair-transplant-shock-in-plants.htm, https://www.gardeningknowhow.com/ornamental/flowers/phlox/growing-garden-phlox.htm. It creates small to large, brown blister formations on leaves. Leaf spot begins in the lower leaves, causing them to dry and drop prematurely. I have heard that creeping phlox has a certain life span and, if so, is it time to dig mine? We planted this about 6 weeks ago and it bloomed already and looked nice. Pruning the stems down to five or six stems per plant increases air circulation throughout each plant, and dividing each plant every two to three years decreases the instance of disease. They pierce and suck the life and nutrients from the leaves of garden plants such as phlox, resulting in yellowing, browning and eventually wilting and dropped foliage. Proper cultural care improves the health and vigor of garden phlox, making it less susceptible to problems such as rust. It creates small to large, brown blister formations on leaves. Rust is another common problem that causes brown spots on phlox foliage. A. There is no powdery mildew present. Spider mites come in all colors, including brown, black and red. How to Treat Rust Disease in Dianella or Flax Lily Plants, Pink Flamingo Lily Leaves Are Turning Yellow & Brown, Chicago Botanic Garden: Plant Evaluation Notes -- An Evaluation Report of Selected Phlox Species and Hybrids, National Gardening Association: Plant Care Guides -- Phlox, University of Minnesota Extension: Tall Garden Phlox for Minnesota Gardens, Texas A&M AgriLife Extension, Texas Plant Disease Handbook: Phlox. Spray the insects with an insecticidal soap product as directed on the label. adds a burst of color and texture to a garden in spring and summer. Remove and dispose of wilted and/or diseased foliage and stems. Question by elbriggs June 23, 1998 . phlox leaves turning brown. Phlox foliage with brown spots, each about 1/4 inch in diameter with a white or gray center, indicates leaf spot is a problem. Answer from NGA June 23, 1998. If the weather is particularly warm or dry, you may notice tiny brown spots moving on the underside of phlox leaves. Like other phlox diseases, rust is an indication that the affected plant does not receive the proper cultural care. Sign up to get all the latest gardening tips. Madison, WI. If you don't have an account sign up for an account now. This will be transplant shock … From here, proper care will ensure a good recovery, but it may not look too healthy until next year. Spider mites are rarely a problem in cool, wet weather, and they can be removed easily by spraying the foliage during early morning with insecticidal soap or, for a severe infestation, a miticide formulated for flowering perennials or ornamentals. It is caused by a number of fungal pathogens, one of the most common of which is Septoria divaricata. Sign up for our newsletter. Well-draining soil, proper spacing and proper pruning also are essential for phlox's good health. The blisters are moist in appearance and have an outer skin, or coating, that easily breaks, emitting tiny spores that are also brown. Phlox's soil should be kept moist but not overly saturated.