A lot of the great unwashed plant marigold because they ’re so easy to grow . They reseed themselves without becoming invasive , tolerate drought , and hardly seem bothered by pests or disease .
But no flora is impervious to problems .
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Photo by Whitney Cranshaw, Colorado State University, Bugwood.org.
Marigolds can be attacked by many different disease pathogens , though it does n’t happen too often . Typically , marigolds will be struck by disease only when they ’re already stress .
herd , overwatering , and ill drain grease can all institute disease your elbow room .
Sometimes , even despite our best efforts , soft - going plants like marigold might be infected by pathogen like kingdom Fungi or bacteria .
It ’s thwarting , but disease do n’t have to spell tragedy . Coming up , we ’ll discuss the most common marigold disease and how to deal with them . Here are the baddies to watch out for :
9 Common Marigold Diseases
Many disease can be avoided by using smart gardening practices like crop rotation , careful watering , appropriate spacing , and cleaning your garden tools in between use .
But if all that fails , this guide will walk you through what to do .
1. Alternaria Leaf Spot
There are several diseases that can cause spots to form on the foliage of marigold plants .
Alternaria tageticais a fungus that causes benighted brownish or bootleg spot to form . These spot may or may not have a yellow , chlorotic gang around the gross profit .
The spots will eventually farm and combine until the entire leafage is dead , at which point , it might fall from the plant .
It ’s not just the leaf that are impacted , though they ’re usually the first to show symptoms . The bloom petals might also develop spotting and will turn black and shrivel up .
The first step is to remove any diagnostic leaves or flowers .
Be exceedingly thrifty not to get any piss on the leaves of the plant when irrigating , because this will just activate the pathogen to spread out even further .
Then , spray every few weeks with a copper antifungal and a product that contains mancozeb .
Copper acts as a protectant , make a protective barrier that fungous pathogens ca n’t penetrate . Mancozeb disrupts the aliveness cycle of the fungus kingdom .
Together , they give you a fighting opportunity against alternaria . Spray them at the same time , admit the first to dry before apply the next product .
Bonide Liquid Copper Fungicide
you may pick up a 32 - ounce ready - to - use bottle , a 16- or 32 - snow leopard ready - to - spray bottle for your hose , or a 16 - snow leopard concentrate of Bonide Liquid Copper Fungicideat Arbico Organics .
In the time to come , appropriate spacing , thrifty weed control , and crop rotation every other twelvemonth will aid keepA. tageticaaway from your marigolds .
2. Aster Yellows
Pretty much every plant inthe Asteraceae familymay be impacted by aster yellow .
It ’s spread by aster leafhoppers ( Macrosteles fascifrons ) , which carry the bacterium - alike phytoplasma that causes the disease .
The symptoms can be a little all over the place . Typically , the figure between the venous blood vessel will turn yellow or white but the vein remain green .
The leaves might also distort and distort . Flowers will exhibit discoloration and deformed growth .
The blossom fountainhead might get foliage - comparable formations and outgrowth that bet like a 2nd head coming out of the center of the efflorescence .
There ’s nothing you’re able to do to cure this disease . You ’ll have to take out the works and dispose of them .
Ourguide to aster yellowscan help you understand the way out and learn how to attempt to prevent it .
3. Bacterial Leaf Spot
Bacterial leafage position sucks . Not because of the way of life it deface a plant life , but because there ’s no known cure . You ’ll have to tear out the industrial plant .
Because there are several diseases that may get spots on the leaves , you ’ll desire to verify you positively key the symptoms you see as bacterial leafage point , not alternaria or septoria .
Look for colored browned or black spots with purple margins .
have by the bacteriaPseudomonas syringaepv.tagetis , this pathogen only impacts marigolds .
But once it ’s in your garden , you wo n’t get rid of it unless you take out all the marigolds you have and leave them out of your garden totally for at least a twelvemonth or two .
It spread via body of water , so avert overhead lacrimation can help to foreclose it from distribute .
4. Botrytis Blight
Also bed as gray mold , botrytis blight infect a wide-cut range of plant . Marigolds are just a few among stacks of species , and unfortunately , this disease can be difficult to prevent and control .
When the fungusBotrytis cinereainfectsTagetesspecies , it causes water - soaked lesions on the stem , leave of absence , and flowers .
The tissue inside these lesions will eventually kick the bucket . Once they do , gray mold colonizes the dead tissue .
Botrytis can lay hibernating in dead or living tissue , waitress for the idealistic conditions with lots of moisture and temperatures between 65 and 75 ° F .
Prevention includes taking caution only to water supply at the soil level and not on the plants themselves .
Straw mulchcan helper to keep water from splashing up onto plant , and appropriate spacing helps too . If you crowd your marigold , it increases humidity and the time it acquire for plant to dry out out .
Typically , it ’s best just to pull any infected plants or prune off the infected parts .
Unless you have an of import reason to sample and control the disease on your plants , such as a sentimental favoritemarigold you ’ve been cultivating via seedseason after time of year , there ’s no reason to employ chemical substance treatments .
For that reasonableness , we ’re only lead to hash out biological control .
When it comes to controlling an existing infection , this requires a multi - step approaching . You need to address the spores as they wake up and start spread in the fountain and again in the fall as the weather starts to cool .
You also want torotate the chemical substance you use , because the fungi can promptly become resistantto whatever you use .
In the spring , use something that will attack the grow spores , such as a product containing the good fungiTrichodermaspp . orUlocladium oudemansii(strain U3 ) .
BotryStop WP containsU. oudemansii(strain U3 ) and was developed specifically to stop botrytis from grow and spreading .
BotryStop WP
It ’s available in a 12- or 30 - hammering supplyat Arbico Organics . Go in with your friend to split it .
The following year in the spring , alternative with something like RootShield ® Plus WP , which containsT. harzianumstrain T-22 andT. virensG-41 .
RootShield ® Plus WP
It ’s alsoavailable at Arbico Organics . snap up it in one- , three- , or 50 - pound packages .
Then , just before the fall of the second class , tack to something unlike to tackle any spores that survived the first round of treatment .
Mycostop biofungicide contains the beneficial fungusStreptomycesstrain K61 . Apply it every few weeks to spray your plants in the late summer before fall symptom appear .
Mycostop Biofungicide
Purchase five or 25 gramsfrom Arbico Organics . A trivial goes a long way , and you ’ll discover this biofungicide is extremely useful for addressing lashings of unlike fungous event .
5. Fusarium Wilt
The soilborne fungus that causes Fusarium wilt , Fusarium oxysporumf . sp.callistephi , is a real jerk .
The pathogen can survive for twelvemonth and years in the ground , and the available treatment does n’t work well .
Symptoms include wilting even when plant receive the right amount of water , and the demise of immature seedlings as well as mature flora . You might even see benighted streaks running up one half of the plant .
Some septic marigold might not produce seeds , or if they do , seed production will be greatly melt off and these will often be unimaginative . Overall growth might be stunt , and the root might turn black .
If you notice your plants have symptom , your only unspoiled selection is to pull and dispose of them . Do n’t put them in your compost .
Then , plant any future marigolds in container with fresh potting mix instead of in the garden beds , at least for the next five years or so .
6. Root Rot
Are you noticing stunted , wilting marigolds in the garden ? Are farewell or flowers turning yellow or brown and dying ? They might have root rot .
because of the fungusRhizoctonia solaniorPythiumoomycetes , it can also cause the stems to crack and the roots to wrench dark-brown and mushy as they rot away .
Only a lab test can tell you which pathogen is cause the problem , but it does n’t weigh much . Both thrive in 75 to 85 ° farad temperatures and lots of moisture . They can be broadcast on tools , through water , or in contaminated soil .
That ’s why dear garden hygienics is crucial . Always sanitize your tool , whether you do that by washing them with easy lay and water , soaking them in a 1:9 solution of bleach and body of water , or both .
Ensuring that you plant in well - draining dirt and avoiding overwatering will also help to prevent rot .
deplorably , if your industrial plant are infected , the upright selection is to draw and dispose of them .
7. Septoria Leaf Spot
Another disease that results in spots on the leaves , this one is get by the fungusSeptoria tageticola .
It differs from Alternaria in that the spots are greyish - black and they miss the greensick ring . Inside the rotting round , you ’ll see fungal spores if you search closely .
Typically , the job get at the bottom of the plant and go higher up as the disease progress .
As with so many fungous pathogens , it boom in temperature above 60 ° atomic number 9 , especially when there ’s also lots of moisture present , whether that ’s from rainfall , high humidity , or irrigation .
seed might be infected and the disease will later appear on mature flora , or it can be transmitted in water or on G creature . That ’s why watering at the filth grade , good air circulation , and appropriate spatial arrangement are critical .
To kill any pathogens on the seeds , pawn them in 115 ° F water for 30 minutes . Plant direct away .
Cut off any infected leaves and plow the plant life with a Cu fungicide every three workweek for as long as symptoms are present .
8. Tomato Spotted Wilt Virus
This disease is spread out by a virus that causes young leave to turn bronze and older folio to develop dark spot .
As the name suggests , it also make the industrial plant to wilt . flower might also fail off .
Tomato discern wilt virus is spread by westerly peak thrips ( Frankliniella occidentalis ) , so control them helps to keep your marigold and many other plants safe .
Our guide to verify thripscan help you with that .
But once it ’s present , the only thing you may do is rip out and dispose of the septic plant .
It might be tempt to just leave them in the ground , but this virus attacks all sort of metal money , including nightshade , legumes , and cucurbit .
If you’regrowing marigolds as a associate plantto essay and ascendance plague , it wo n’t do much good if it deflower yourtomatoharvest .
9. Verticillium Wilt
This disease is because of the same pathogen that infects box elder tree andwatermelons – the fungusVerticillium dahliae . In other words , it ’s a trouble for a huge reach of plant .
In marigolds , it causes part of the works to droop and die , with lily-livered and brown leaves . As the disease spreads , the total flora will die . While it can take eld to stamp out a large plant , a marigold might die in a few months .
The disease attacks the root first , killing them . That ’s what in turn do the upper component of the plant to die .
The fungus kingdom can live in the soil for a long time , and it can subsist on fallen industrial plant junk . harvest gyration , solarizing dirt , and cleaning up the garden in the gloaming are all efficient in at least decelerate its spread .
commend that Mycostop biofungicide we mentioned above ? It ’s an in effect discussion for vert . Just be trusted to play along the maker ’s directions closely .
Make Your Marigolds Merry
Do n’t scroll through this lean and conclude that marigolds just are n’t deserving the trouble .
True , there are many diseases that can attack marigolds , but they seldom do . specially if you use bright garden practice like crop gyration , appropriate spacing , and water at the soil level .
If you grow your plants in pot soil in a container , you lose weight the chances of contracting any of these diseases even more . Andmarigolds are so cute in containers !
If you ’re ready tocontinue your marigold - grow adventures , we have scores of guide to help you on your way :
© take the Experts , LLC . ALL RIGHTS RESERVED.See our TOSfor more details . Product photos via Arbico Organics . Uncredited photos : Shutterstock .
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Kristine Lofgren
