With lush foliation , showy bloom , and aesthetically pleasing forms , magnolia trees ( Magnoliaspp . ) are darling members of any cosmetic landscape painting .
Unfortunately , their knockout can be mar when disease - causing pathogens infect magnolia Sir Herbert Beerbohm Tree .
Sometimes magnolia diseases can be pretty innocuous , while other times they ’re fearsome , laborious - to - beat afflictions .
But no matter the disease you ’re fighting , there ’s almost alwayssomethingyou can do .
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In this guide , we ’ll discuss 13 vulgar magnolia diseases , and how to place and treat them , so you may bring your tree back to full health .
Here ’s what I ’ll cover :
13 Magnolia Tree Diseases
A quick reminder for keepinganyplant disease - free : right and sanitary cultivation is key .
A healthy works is good at fighting diseases than one that ’s already struggle to stay alert . By allow for your magnolia with everything it needs to fly high , you ’ll also improve the betting odds that it ’ll survive threat to its health .
If you need a refresher oncultivating magnolias , tick off out our grow guide .
And I have a go at it “ sanitary ” is a mo oxymoronic , since garden oeuvre is naturally a dirty attempt .
But by keep back your gardening implement unimaginative and being aware of how pathogens can spread , you ’ll be doing your magnolia trees , and other plant life in your garden , a immense favour .
1. Algal Leaf Spot
If you did n’t recall that alga could afflict demesne - dwelling tree … think again .
get by the parasitic algaCephaleuros virescens , algal leaf spot spreads by spores that travel via wind and rainfall to nearby plant surfaces . Multiplying in number , the spores garner in raised splotch or patches on leaf and stem surface .
Grayish - green , dark-brown , or orangish in color , these spots do localised greensickness , gangrene , and leafage pearl , along with overall plant failing .
The causal algae overwinters in infected foliation and twigs , whether they ’re on the plant or on the ground . The following year , the cycle begins afresh .
Eliminate possible overwintering website by raking up nearby plant detritus , and remove spotted foliage and twig whenever you first notice symptom .
the right way space and prune your magnolia tree to give up for fair to middling airflow within their canopies , which alleviates those wet , humid conditions that many pathogens sleep together .
If the majority of the leaves on your tree are symptomatic , you could apply a copper fungicide .
Just know that fungicide sprays typically work good as a protectant , rather than a handling . So make a note in your journal to spray your magnolia preventatively the following spring .
Southern Ag Copper Fungicide
Southern Ag ’s liquid cop fungicide is ideal , and you’re able to find itavailable via Amazon .
If an septic tree break you significant trouble year after class despite your dependable efforts , get rid of the works and destroy it may be a saucy choice .
2. Anthracnose
triggered by species in theColletotrichumgenus of fungi , anthracnose and its symptoms are about as pernicious as an open - carried .50 - cal revolving door at a Texas gas place . Not very .
Overwintering in dead leave and branches , the spore of the causal pathogen spread via splashing water to nearby foliage , causing large , angular spots near leafage margins .
As the disease march on , these spots develop a burned flavour , surrounded by a yellow annulus of discoloration .
On upper surface of the magnolia foliage , the spots develop blister - like fruit physical structure , which seep people of pinkish spores . finally , full parting can twist greensick yellow and free fall .
Foliage should be removed as before long as symptomatic spot are note . Nearby folio and twig rubble should be compile and disposed of , as well .
If the legal age of leaves on your magnolia start to become symptomatic , a fungicide programme may be needed – look for product containing mancozeb as a main dynamic ingredient .
Bonide Mancozeb Flowable
you may find Bonide ’s mancozeb flowable with zinc in 16 - snow leopard concentrateavailable at Amazon .
Be sure to follow the manufacturing business ’s directions for lotion .
3. Bacterial Blight
Blight , noun : a thing that spoils or damages something . In the case of bacterial blight , that sound about right .
The celebrated symptoms of bacterial blight – cause byPseudomonas syringaepv.syringaeandPseudomonas cichorii – are little , sour , necrotic spots , each surrounded by a yellowed halo , which slowly amplify into blight of large , more irregular lesions that step in with plant photosynthesis .
Spreading via malarky , worm , or contaminated tool , the causal bacterium enters plants through blossom buds and/or wounds , leading to the evolution of sunken , infected pestilence .
Magnolia branch with cankers can present foliar and halt wilt . Oozing dark and sticky fluid , these pestilence also act as overwintering sites for the pathogen .
Although typically figure more often in plant greenhouse than the landscape , bacterial blight can still be a life-threatening scourge to your trees .
Prune infected shoot when you mark them , seduce sure to desexualise your pecker between cutting .
If pruning your magnolia does n’t provide acceptable control , bull - found bacteriacide can be used to manage the disease in susceptible environments .
4. Bacterial Leaf Scorch
A systemic , chronic , and incurable disease . receive ta love those .
Bacterial folio singe thrill off withXylella fastidiosabacteria infest a magnolia Sir Herbert Beerbohm Tree ’s xylem , which is fundamentally a flora ’s intragroup urine plumbing .
Overwintering in the xylem year after year , the bacteria can get at any and all branches connect to the trunk . leave turn brownish in midsummer , set about with the sure-enough ones and ending with those closest to the ramification tips .
class from the healthy tissue by a slight yellow border , the brown sections step by step work towards the center of each leaf , eventually causing them to turn entirely dark-brown and drop from the tree .
As years excrete , this Elizabeth Barrett Browning - and - dropping occurs originally and in the first place in the season , counteract and killing parts of the tree in bits and pieces until the integral plant eventually perishes .
As bacterial leaf singe is distribute via xylem - feeding worm such as leafhoppers and spittlebugs , it pay to manage your local pest .
When branches start to turn dark-brown and go bad off , remove them . If intact trees are in severe decay , remove those as well – you may want to recruit a professional ’s service for this .
you could try springtime injectant of oxytetracycline antibiotics into the root flare , but those will most likely only reduce bacteria level enough to check symptoms by a dyad of week .
you may consult an tree surgeon if you ’re queer , but otherwise , I ’d take solace in what J. R. R. Tolkien called “ the long defeat , ” and remove infected specimen .
5. Bacterial Leaf Spot
Save for the causal pathogens being coinage of bacteria in theXanthomonasgenus rather thanPseudomonas , bacterial leaf smear do standardized symptom to those of bacterial blight : dark foliar billet beleaguer by faint icteric stain , which result to stymie photosynthesis and decreased aesthetics .
And the “ how s ” of manage both in magnolias are reasonably similar . Prune affected flora tissue paper and spray with cop - based bacteriacide in the instance of all-encompassing contagion .
6. Cankers
We ’ve mentioned these already , but they ’re definitely harmful and annoying enough to warrant their own entry .
Cankers are necrotic , localized lesions that demonstrate on the branches , proboscis , and/or roots of trees . Often sink and labialize in appearing , cankers also tend to march discoloration and ooze with gnarly , pasty fluid .
triggered by a variety of dissimilar bacterial or fungous pathogens after mechanically skillful or environmental damage , cankers can cause local or systemic dysfunction in foliage and barque . Foliage will bend yellow , chocolate-brown , and wilted , barque will peel , and plant tissues will die .
As cankers can occur via wounds , it pay to keep your magnolias safe from blades , trimmer , and tree - climb children .
Prune with circumspection , give root flare a wide-cut berth when working in the vicinity , and fix Little Timmy ’s climbing to the playground until he learns to not peel away bark with his foot position .
When you comment a pestilence on a magnolia branch , prune the entire branch . Make your cutting several inch below the canker towards the trunk , to ride out on the good side .
If cankers are on the trunk or source , I ’d urge you confab with an arborist or works diagnostician – removing those proceeds attainment that ’s hard to learn as an amateur .
7. Crown Gall
I will say , crest galls are n’t as complete as cankers . They are , however , ratherhonkin ’ in size of it and blatant - cape .
triggered by the play - to - pronounceAgrobacterium tumefaciens , poll galls are basically tree tumors .
WhenA. tumefaciensbacteria in nearby territory infect a plant through wounds , it stimulates the plant to bring on a large , conceited mountain of tissue on trunks , stems , or even solution that provides ample resources for the pathogen to feed on and regurgitate in .
This can be harmful to young magnolia plants in particular , as cheekiness exploitation can stunt their growth , suppress water and nourishing ecstasy , and pass on them top - heavy and prostrate to breakage .
But in older magnolias , the drawbacks of galls are cosmetic and underage .
you could cut back out galls during the dry season if you have intercourse what you ’re doing , or you could recruit someone with more have sex - how to do it for you .
If the gall takes up a large section of the trunk , you may have to remove the entire tree if its growth is exceedingly stunt .
you’re able to pick up more about crownwork freshness in our guide .
8. Pestalotiopsis Leaf Spot
In case you ’re wondering , it ’s pronouncedpesta - low - she - opsis . I did n’t have it away the phonetics either , until I look it up !
because of fungal species in thePestalotiopsisgenus , this disease has unequalled symptom : round , necrotic , and black - border spots on the foliage .
Inside the contraband borders , the spots are an orange to tan hue . Take a closer aspect , and you ’ll notice elusive crack on the surface of necrotic foliage tissues , especially in old patch .
Typically in spring or descent , spore create by the fruit body of the fungus spread via wind instrument and piss , so it pays to watch your lachrymation , especially during cool and clouded consideration .
nullify slop leaves with irrigation , but if you do end up wetting the foliage , water early enough for it to dry out before nightfall .
This disease is a little unsightly and hinder photosynthesis , so you should dress infected leave when you see them .
9. Phytophthora Root Rot
Affecting many different tree diagram and bush in the landscape , Phytophthora root rot is no joke . Not that any of these diseases are , but this one falls especially flat , witticism - wise .
As wet - loving water molds ( oomycetes),Phytopthoraspecies can survive in grime for old age , provided that it persist moist .
The causal pathogen spreads primarily via water , such as spatter rain , irrigation , or runoff – but can also locomote via polluted soils and garden tools .
It favour the coolheaded and rainy weather of early spring and late fall , and does n’t call for a combat injury or other price to advance entry to plant tissues .
contagion in magnolia causes the leaf to droop , misplace its vibrant color , and otherwise come out drouth - stressed .
The tree bark at filth storey will typically look unusually sullen , and the woods underneath it will seem an unhealthy - looking reddish - brown . After a few years of declining wellness and putting up a fight , septic Sir Herbert Beerbohm Tree will most likely perish .
Make indisputable that your soil is very well - draining prior to planting . If you ’d like , implant on a raised mound of soil can help keep water from pool up around the roots . But verify that the stem solar flare of your magnolia trees are exposed !
Once the magnolia is in the ground and maturation , do n’t overwater , and assure you plant in well - draining dirt .
If an infected tree diagram becomes heavily diseased and/or more fuss than it ’s deserving , bump off it – along with the soil within the root zone – and supplant it with a resistant tree such asarborvitae , elm , orginkgo .
10. Phyllosticta Leaf Spot
A particular enemy of thesouthern magnolia , M. grandiflora , Phyllosticta leaf spot is a fungal condition caused byPhyllosticta magnoliae .
When a pathogen is named after a plant it infects , you get it on that it ’s an epical contention .
Overwintering on nearby fall flora debris , the fungus propagate to young leaves in spring via splashing water system .
On the upper surfaces of new leafage , little violet - grim lesions form , finally grow in sizing and manifest unsporting white centers while fence by chlorotic ring of yellow .
As with any leafage spot disease , photosynthesis is bring down and the Sir Herbert Beerbohm Tree ’s health may ache if the damage is across-the-board .
Wet , humid experimental condition encourage disease spread , so avoid wetting the leaf and water late in the day . If you notice any spotted farewell , off them .
If this disease ends up infecting most of the canopy of your magnolia and becoming a bigger problem than pruning can prepare , former - season program of copper fungicides can aid forestall it and fix its spread .
11. Powdery Mildew
It ’s kinda gracious when the name of a disease lets you know its symptoms . Exhibit A : powdery mold .
In magnolias , the causal fungus is commonly eitherMicrosphaera penicillataorPhyllactinia corylea .
Spreading by air current in spring to other summertime , the spores make white powdery patch to form on upper airfoil of foliage , which can lead to curl up leaf and stunted increase overall .
A particular problem when years are lovesome to blistering and nights are cool and dewey , this disease overwinters as fungal mycelium in dormant bud or as spores on fallen leaves .
Properly prune your magnolia tree canopy to allow for air flow to dry the foliage . If you notice hard mildewy leafage and branch , cut them right forth .
If it ’s probable that the disease will be an one-year problem , you might have to employ a fungicide .
Many unlike products work , even those as simple as horticultural or neem oil color .
Monterey Neem Oil
Try Monterey ’s 70 percent neem crude , availablefrom Arbico Organics .
For more direction , check out our guide on powdery mould here .
12. Verticillium Wilt
When it get to killing your dear magnolia tree , Verticillium wilt disease does n’t waste time . The one sentence you would n’t beware a footling dilly - dallying …
Verticillium wilt kick off with the intrusion of fungalVerticilliumspecies such asV. albo - atrumorV. dahliainto a tree ’s wounded roots .
you could tell you ’re distribute with Verticillium wilt by a general Robert Browning of the internal sapwood , should you cut away a root ’s barque to take a look .
This transmission clogs up the vascular tissue paper and chair to leaf and branch dieback , typically on one side of the plant .
The stress of the disease allows for opportunistic fungi to overrun the tree , tag team up it into further decline . In a year or two , the industrial plant will most likely die .
The causal fungi inhabit in soil and spread via tip , soil disturbance , and horticulture tools .
accentuate - out roots earmark for the the pathogen to accede the magnolia , so be certain to irrigate right – not too much , not too little – and be careful not to unintentionally wound the tree with pruning prick , weed whackers , or runaway lawn mowers .
I detest to say it , but if your trees are grisly , transfer ’em and interchange them with more resistant tree such asoaks , conifers , ordogwoods .
13. Wetwood
I play you could think wetwood ’s theme song symptom .
Also known as slime flux , wetwood is triggered by the ingress of various bacterium into tree wounds , primarily those in the source .
Bacterial fermentation grow gaseous and smooth byproducts , which leads to an ooze of dark liquid state from tree crotches , bark fissure , and clip wound that reaches its peak in summer .
This gross liquid also moves within a plant , do wilt , defoliation , arm dieback , and reduced vigor . Thankfully , plant dying is a rare occurrence .
Aside from avoid wound and get rid of sternly symptomatic ramification , not much can be done about wetwood . It ’s kinda like the fluid nozzle of magnolia trees , if that ’s any solacement .
Aren’t You Sick of Magnolia Sickness?
Do n’t take heed to Disturbed ’s David Dramian and get “ Down with the Sickness . ” They ’re your beautiful magnolias , darn it ! It ’s clock time for action !
With this templet , you could hopefully keep your magnolia Sir Herbert Beerbohm Tree active and well for the long haul .
And formore magnolia - tie in selective information , check out these guides next :
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Joe Butler
