Learn how to deal with these common woes and foes to ensure hydrangea blooms for generations
As one of the most popular inflorescence shrubs for the modern landscape , it is no surprise that we are now seeing more evidence of various diseases and worm harm onHydrangeasp . It was once a plant life rarely afflicted by pests , but extensive use in the landscape painting has create more opportunities for uncouth pest problem .
Leaf Spot Diseases
Two common foliage place diseases impact hydrangea in similar ways but with various sources . In both cases , the plants profit from murder diseased leaves from the domain . Pruning also open up the plant and allow for secure air circulation , which can help in keeping these problems under control . Diseased or infested subdivision of your plants should always be bagged and set in the trash or burned if tolerate , never compost . All pruning tools should be clean thoroughly and disinfected between plants .
Fungal leaf spot (Cercosporaspecies andPhyllosticta hydrangea)
Yellowing leave with circular spots , typically chocolate-brown or purple , at the base of the plant can usually be attributed to one of two pathogens , both fungal diseases . fungous leaf spot ( Cercosporaspecies andPhyllosticta hydrangea ) can be prevented by keeping the farewell juiceless when water . However , red-hot , humid weather and big rain can not be prevented . Wet atmospheric condition patterns create the perfect condition for spreading these pathogens . If your plant become infected , treat them with a commercial fungicide contain Chlorothalonil , or use organic options . Compost tea leaf , garlic oil , melted kelp , and atomic number 1 peroxide are recommended as well as Neem Oil and sprays that containBacillus subtilis . With that said , this disease is cosmetic and will not kill the plant .
Bacterial leaf spot (Xanthomonas campestris)
A disease common to oakleaf hydrangea ( Hydrangea quercifolia ) is bacterial leaf spot ( Xanthomonas campestris ) . Entering the plant through wounds and natural openings such as the stomata in leafage , purple or reddish - dark-brown foliage spots appear in June , gradually changing to angular shapes , originate , and eventually killing the infected leave of absence . crocked , warm weather activate its appearance . set out at the bottom of the plant , splash water spreads the pathogen upward . Treating the flora with Cu hydrated oxide can provide some protection . Hydrangea arborescensandH. macrophyllacan also be affected , but the disease has the greatest impact on oakleaf hydrangea .
Common Hydrangea Pests
Aphids
Aphids ( Aphidoidea ) do not spare hydrangea . Pinhead - sized , soft - bodied 1/8”-long insect that come in assorted color , based on which of the 4,000 dissimilar species you have , Aphids can quickly stimulate tremendous price . assault in large groups , they prick the leave and stems , sucking out the liquidity , causing them to dry out up and die . A muggy residue calledhoneydewis left behind . Honeydew is attractive to ants , so their swarm on your plants may be the first sign of aphid difficulty . Control with a strong spray of water system to bump the pests , then remove infested branches , or use an insecticidal soap . When aphids are out of control , the sticky honeydew can turn into a settlement of sooty mould fungi ( Capnodium citri ) hit you with twice the problems .
Scale
One of the worst affliction for any plant isscale ( Coccoidea ) . They are surreptitious , taking up residence in space where you may not see them until there are one C . A small-scale ancient insect of over 8,000 trenchant specie that suck on sap from the leaves and stems of plants , they may look like sap , bark , cotton plant , or mottling on a foliage from a aloofness . One of the most common found on hydrangea is aptly name hydrangea scale ( Pulvinaria hydrangeae ) , which has a cottony visual aspect . female develop in two stages before becoming adult , resulting in two specific sentence that one can apply ascendance . Dormant and summer horticultural oils are used when the insect is in the crawling stage . Consult your local conditions information or expert to determine the right diligence time . A few soft insects can be spray with a 1:7 ratio of itch intoxicant and pee every 3 day until no insects remain . Removing the infested parts of the works may be necessary if there are too many insects to treat otherwise .
For more data and strategies , check out :
And for more Midwest regional reports , click here .
Marti Neely , FAPLD , owns and operates Marti Neely Design and Associates in Omaha , Nebraska .
Fine Gardening commend intersection
A.M. Leonard Deluxe Soil Knife & Leather Sheath Combo
Fine Gardening receives a commission for items buy through links on this site , include Amazon Associates and other affiliate ad programs .
Get our latest tips , how - to articles , and instructional videos sent to your inbox .
sign up you up …
Related Articles
How to Manage Common Summer Pests: Whiteflies, Mites, and Scale
What’s Wrong with My Hydrangea? Learn to Recognize and Treat Common Diseases
Solutions for Summer Squash Pests and Diseases
Pests and Diseases to Watch Out for in Dahlias
bring together Fine Gardening for a free engage live webinar featuring Dr. Janna Beckerman , a renowned plant pathologist as well as professor emerita at Purdue University and the ornamentals technical manager …
When I recognize a special Amandine Aurore Lucie Dupin dollar cactus ( Astrophytum asterias ) at the Philadelphia Flower Show a few months ago , I sleep with I was in trouble . With a delicious color formula …
When we only prioritise plants we require over flora our landscape painting needs , each season is filled with a never - ending lean of job : pruning , pinch , lachrymation , treating , amending , and fertilizing , with …
Subscribe today and save up to 47%
Video
Touring an Eco-friendly, Shady Backyard Retreat
You must be careful when you come in the backyard of garden designer Jeff Epping — not because you ’re potential to trip on something , but because you might be dive - bombed by a pair …
4 Midsummer Favorites From a Plant Breeder’s Garden
Episode 181: Plants You Can’t Kill
Episode 180: Plants with Big, Bold Foliage
4 Steps to Remove Invasive Plants in Your Yard
All Access members get more
Sign up for afree trialand get access code to ALL our regional content , plus the remainder of the member - only content subroutine library .
part Free Trial
Get complete situation access to expert advice , regional contentedness , and more , plus the print magazine publisher .
Start your detached trial
Already a member?enter
The right kind of hydrangea will attract all kinds of pollinators to your garden, but it might also attract some unwanted guests. Photo: Kristin Green
Though an unsightly ailment,Cercosporaleaf spot will not lead to the death of your hydrangea.Photo: Penn State Department of Plant Pathology & Environmental Microbiology Archives, Penn State University, Bugwood.org
Xanthomonas campestris, very similar in appearance toCercosporaabove, can kill infected leaves, so close monitoring is necessary for proper identification and treatment.Photo: Elizabeth Bush, Virginia Polytechnic Institute and State University, Bugwood.org
Aphids reproduce at a very rapid rate, so populations will continue to multiply and create large infestations if not controlled.Photo: courtesy of Paul Thompson
Ants will also tend and protect scale, like this cottony-cushion scale pictured here, for the honeydew they secrete.Photo: Ron West
