smear may be cunning on a puppy . But on a Nipponese maple ? Not so much .
Not only do spots on the leaf make your Japanese maple look tatty , but it ’s your tree ’s way of telling you there ’s trouble afoot .
We link to vendors to help you find relevant products . If you buy from one of our link , we may earn a commission .
Photo via Alamy.
While Japanese maples are n’t particularly weak orsusceptible to disease , they are often small in height .
That matters because a fungous infection that get some defoliation on a monumental tree will likely have less of an impact overall than it will for a small specimen that does n’t have as many leaves to fall behind .
So , let ’s speak about the disease that cause these spots and when they might become something to worry about . Here ’s a quick preview of everything we ’ll go over :
Photo via Alamy.
7 Leaf Spot Diseases in Japanese Maples
check that you ’re familiar with theins and out of evoke Japanese maplesbefore we start our journey here . A lot of disease can be avoided with right caution .
Make looking over your Japanese maples a regular part of your routine – it ’s much easy to resolve an issue when you catch it early on on rather than waiting for it to get out of hand .
No matter the suit , your trees will be far less probable to experience disease problems if yourake up strike leaves in the autumnand water at the filth storey rather than on the leave of absence .
countenance ’s look at the ailments that may cause pick out on Nipponese maple leaves .
1. Alternaria Leaf Spot
Fungi in theAlternariagenus do dark brownish to black spots on the foliage . These spots may or may not have yellow halos .
If the leaves are heavily infect , they will cast from the tree diagram . In bad infections , a young or small Japanese maple can be completely defoliated .
Since the pathogens that cause this disease thrive in coolheaded , crocked atmospheric condition , it ’s no surprisal they ’re most active during the spring and taper off a bit during the summer .
When temperatures are mightily between 70 and 82 ° F , the fungus kingdom are most fighting , but they can grow outside of these temperatures as well .
Silver ( Acer saccharinum ) andsugar maples(A. saccharum)are more susceptible , but if you notice the symptoms on a nearby maple of another type , be aware that it could also be coming for your Nipponese maple – peculiarly those that are stressed .
treat Alternaria folio spot is monovular to the process you would utilise to handle anthracnose , which we ’ll sing about next .
2. Anthracnose
Anthracnose occurs in hundreds of species , including miscellanea ofAcer . symptom can vagabond from a few angular spots to complete defoliation .
The temporary spot are tan to black , and typically appear along the nervure and perimeter of the leaf .
The stain might disseminate and merge , finally resulting in folio drop . When the problem is tough enough , it can wholly defoliate a Japanese maple Sir Herbert Beerbohm Tree .
If this happens in the spring , the Sir Herbert Beerbohm Tree will typically develop young leaf and will regain . Trees that are infected during the fall wo n’t develop new leaf until the following outflow .
There are many pathogens that cause anthracnose in Japanese maple , but the most coarse areAureobasidium apocryptum(syn . Kabatiella apocrypta),Colletotrichum gloeosporioides , andDiscula campestris .
These are all spread by water , so they ’re typically most fighting in the fountain and declivity , and activity might quit altogether in the summertime .
Do what you could to avoid splashing water on the leaf of your Sir Herbert Beerbohm Tree .
We ca n’t control the weather , but we can control irrigation , and sprinkler render a quick way to spread this disease throughout the garden .
If your Japanese maples have anthracnose , discourse begins in the outpouring .
At leaf bud fracture , spray Tree with a product that incorporate both mancozeb and bull , or one like Bonide ’s Revitalize , which contain thebeneficial bacteriaBacillus amyloliquefaciensstrain D747 .
Bonide Revitalize Biofungicide
This intersection is available in both 16 - snow leopard concentrate and 32 - ounce quick - to - use containersat Arbico Organics .
Reapply throughout the spring following the producer ’s applications programme timing guidelines . you could also reapply again in the fall .
3.Bacterial Leaf Spot
If you growfruit Sir Herbert Beerbohm Tree , lilacs , forsythia , ordogwoods , you might already be familiar with this disease .
It ’s a bacterial infection that enters through wounds on the plant , whether because of insects , pruning , or wind damage , and it do little black smear to appear on the leave of absence .
leafage veins also turn grim , and in particularly tough cases , it can get new shoots and branch tips to sprain black and shrivel up .
This disease is make by the bacteriaPseudomonas syringaepv.syringaeand Japanese maples are unfortunately extremely susceptible .
Even more unfortunate , it ’s hard to control . While you’re able to spray your plant with a fuzz fungicide , the bacteria can become resistant .
The best defense is a effective offense . Avoid pruning during wet weather condition , keep the area around your Japanese maple clear to ameliorate air circulation , and remove any diagnostic plant tissue paper . Also , be careful not to over - fertilize your industrial plant .
If the pathogen assail your tree , spray with copper once a month but not more often than that .
Better yet , substitute Cu with abactericide that containsBacillus subtilis . This good bacteria can hold in and decimate the pathogen that causes this disease .
Use bull one month and yourB. subtilisproduct the next . Stop as soon as new growth look sound .
CEASE Biofungicide
B. subtilisproducts can be hard to find , sohead to Arbico Organicsto grab a gallon or two - and - a - one-half gallon of Cease , which contains this powerful ingredient .
4. Phyllosticta
This disease appears as round yellow or tan blot on the folio . On otherAcerspecies , the spot might also have a purple boundary line .
If you depend closely , the mall might be so fragile as to be transparent , and these might fall out , leave alone small holes throughout the foliation .
Phyllosticta smear is make by the fungusPhyllosticta minima . This pathogen require water to reproduce , and it can go on idle words and water . It can also live on fallen leaves throughout the winter and reinfect your works if you do n’t clean up the junk .
This disease should be filed under NBD , for no vainglorious deal . The symptoms are kind of atrocious , but it wo n’t toss off or even really harm your tree . It just makes it look a bit shabby .
Of of course , we want our Japanese maple to appear as good as they can , so to winnow out this disease , your first labor is to rake up all the leaf around your tree as presently as you descry signs of a problem , and do it again in the crepuscle to foreclose any fungi from winter .
Then , spray the tree diagram with copper fungicide . You might also desire to spray the tree diagram in the give after the leave have emerged and matured .
Bonide Copper Fungicide Dust
you may buy bull dust in one - pound or four - pound containersat Arbico Organics . ruffle it with water consort to parcel directions and spray your trees .
5. Powdery Mildew
The fungi that cause powdery mold in maples , Phyllactinia marissallii , like the same weather condition that Nipponese maple do – so it ’s no wonder they go hand in helping hand !
Because this disease is middling common , you want to provide preventive care through proper cultivation .
Start by making sure your tree diagram outride healthy enough that it can withstand the pathogen , or that it wo n’t become highly symptomatic if it is infect .
Do this by planting your tree with the proper calorie-free photo , feeding it regularly as require , and commit it the appropriate amount of water .
Keep the Nipponese maple pruned , water at the grease level , and check on your Sir Herbert Beerbohm Tree regularly to see if any symptoms are developing . Treating powdery mold early on is a fortune easier than waiting until the problem is life-threatening .
P. marissalliionly set on plants in theAcergenus , and other kingdom Fungi that make powdery mold in other species wo n’t attack type ofAcer .
So you do n’t have to panic if yourpumpkins have powdery mildew . It does n’t mean your Japanese maples will also contract the disease , though it does indicate that the condition are proper .
Nipponese maple rarely get gravely sick with this ill , but if you start to see a pulverization - corresponding coat on the leave in smirch or patches and maybe some foliage turning lily-livered , it ’s time to act .
Neem fossil oil , copper fungicide , or a product that contains the beneficial bacteriaBacillus subtilis , such as Cease , are all good at process powdery mould .
Whichever you select to habituate , keep abreast the manufacturer ’s guidance for software .
6. Septoria
We still call this disease septoria foliage touch though it ’s triggered by the reclassify pathogenSphaerulina aceris , formerly known asSeptoria aceris .
This disease causes orotund , brown touch that can run anywhere from the size of it of the tip of a pencil to a half - inch in diam . As the disease progress , the center of the spots will turn lightheaded and will take on a tan or ointment chromaticity .
Look for inglorious fungous bodies inside the smirch on the upper side of the leaf .
Septoria leafage place can be treated with a pig fungicide . Start treatment any meter when symptoms are present and watch the manufacturer ’s directions .
If you desire to spray preventatively , which is only necessary if your tree have had the disease in the past or other nearby plant are infect , begin spray when daytime temperature reach 65 ° atomic number 9 .
7. Tar Spot
I love a disease that look just like you think it would base on the name . It make recognition so much easier . seafarer post is one of those diseases .
do by fungi in theRhystismagenus , it results in dark , raise , round spot that depend like someone dipped a brush in Jack and flicked the tar onto your Nipponese maple .
These spots can be midget or up to an inch and a one-half in diameter . If you touch a spot , it will often feel rough .
The samaras , those little winged ejaculate pods on your maple , can also be covered in seaman - comparable spots .
The disease often starts with small , pale yellowish spot that are easy to omit . It ’s not until summertime make it that the spots sprain fateful and become more trenchant .
This is another one of those diseases that sucks because the symptoms are unworthy . But it does n’t really harm the health of the tree .
Because the spore overwinter on fall leaves , it ’s imperative that you glance over up all the fallen debris in the tumble .
If you do , it ’s unbelievable that the disease will return the next yr in any major way . There ’s no need to handle with fungicide since this problem is mostly cosmetic and easy to check .
Out, Damned Spot!
We love Nipponese maple for their leaves . This is n’t a plant that can hide behind showy peak . Spots spoil their elegance , and they ’re also commonly an denotation that something is wrong .
There ’s so much more tothe cock-a-hoop , beautiful worldly concern of Japanese maples . Here are a few other guides that you might enjoy check out next :
© require the Experts , LLC . ALL rightfield RESERVED.See our TOSfor more contingent . Cartesian product photos via Arbico Organics . Uncredited photos : Shutterstock .
About
Kristine Lofgren
