|Flower failure||Plants do not flower but otherwise appear healthy.||Not a disease||Divide and replant to alleviate overcrowding.|
|Foliar nematode||Brown areas on the leaf are restricted in shape by leaf veins. These angular spots are usually seen on the lower leaves.||Aphelenchoides||Remove the leaves showing symptoms. Thin dense clumps to improve air circulation and irrigate in a manner that keeps water off the foliage.|
|Leaf scorch||Margins of leaves turn red to reddish-brown.||High temperatures, dry soil, windy conditions.||Move the plants to a shady, moist location. Note that leafhopper feeding can also cause leaf tips to redden and brown.|
|Leaf spot||Well defined dead spots form on leaves. Under ideal conditions of wet weather, spots merge and result in large dead areas on the leaf.||Cercospora||When watering plants, do so in a manner that keeps water off the foliage. See the NOTE below.|
|Powdery mildew||White fungal growth develops on the upper surface of leaves.||Erysiphe polygoni||See the NOTE below.|
|Root knot nematode||Galls form on roots and plants may be stunted.||Meloidogyne||Remove infected plants. Cultivate the area to remove all plants and leave the soil bare for a growing season before replanting.|
|Virus||Plants are yellowed but roots appear healthy.||Tobacco ringspot virus||Remove infected plants.|
|Wilt||Plants are stunted or wilted and have brown sunken dead areas on the stem near the soil line.||Rhizoctonia or Fusarium||Remove affected plants.|
NOTE: Although there are no fungicides specifically labeled for Astilbe, there are some for ‘ornamental use.’ These can be applied but the user assumes all liability for possible plant damage. If the label states that the fungicide is effective for a particular plant disease, apply the chemical to a few plants and wait 24-48 hrs to see if damage occurs. If none occurs, it may be safe to use that chemical more extensively on that variety and test it on other varieties prior to extensive use.
NOTICE: THE USER OF THIS INFORMATION ASSUMES ALL RISKS FOR PERSONAL INJURY OR PROPERTY DAMAGE. WARNING! PESTICIDES ARE POISONOUS. READ AND FOLLOW ALL DIRECTIONS AND SAFETY PRECAUTIONS ON LABELS. HANDLE CAREFULLY AND STORE IN ORIGINAL LABELED CONTAINERS OUT OF THE REACH OF CHILDREN, PETS, AND LIVESTOCK. DISPOSE OF EMPTY CONTAINERS RIGHT AWAY, IN A SAFE MANNER AND PLACE. DO NOT CONTAMINATE FORAGE, STREAMS OR PONDS.
Notice: The user of this information assumes all risks for personal injury or property damage.
Warning! Pesticides are poisonous. Read and follow all directions and safety precautions on labels. Handle carefully and store in original labeled containers out of the reach of children, pets, and livestock. Dispose of empty containers right away, in a safe manner and place. Do not contaminate forage, streams or ponds.
Issued in furtherance of Cooperative Extension work, Acts of Congress, May 8 and June 30, 1914, in cooperation with the U. S. Department of Penn State College of Agricultural Sciences research and extension programs are funded in part by Pennsylvania counties, the Commonwealth of Pennsylvania, and the U.S. Department of Agriculture.
Visit Penn State Extension on the web at extension.psu.edu.
Where trade names appear, no discrimination is intended, and no endorsement by Penn State Cooperative Extension is implied.
This publication is available in alternative media on request.
The Pennsylvania State University is committed to the policy that all persons shall have equal access to programs, facilities, admission, and employment without regard to personal characteristics not related to ability, performance, or qualifications as determined by University policy or by state or federal authorities. It is the policy of the University to maintain an academic and work environment free of discrimination, including harassment. The Pennsylvania State University prohibits discrimination and harassment against any person because of age, ancestry, color, disability or handicap, national origin, race, religious creed, sex, sexual orientation, gender identity, or veteran status. Discrimination or harassment against faculty, staff, or students will not be tolerated at The Pennsylvania State University. Direct all inquiries regarding the nondiscrimination policy to the Affirmative Action Director, The Pennsylvania State University, 328 Boucke Building, University Park, PA 16802-5901; Tel 814-865-4700/V, 814-863-1150/TTY.