Smoke Tree Verticillium Wilt

Question: Hello,

I have a question regarding an issue with a young smoke tree in my yard. 

I have a Golden Spirit smoke tree which was planted last spring. It was doing fine until over about a month ago when I noticed that some of its leaves looked dried/scorched (see enclosed images). 

I did some research into what might be causing it and found out it could be verticillium wilt. That got me thinking I should have a soil sample tested for the fungus that causes the disease but I cannot find a single place where soil can be tested for microscleritia. 
And that is my question - can you please advise on labs that run such tests?

Thank you and best wishes,
Izabela

responder: Answered by the Home and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied June 28, 2023, 9:53 AM EDT
response: Hi Izabela,  It does appear to be struggling. Unfortunately, soil laboratories aren't pathology labs so the ones available to homeowners don't test for specific pathogens. If you did send to a pathology lab, likely would be many pathogens present anyways that naturally occur in soils, sometimes affecting plants, sometimes not. Usually these soil pathogens go after stressed plants, so ones with possible root injury from either plants or borrowing wildlife, drought or excessive water stress, weather damage etc. The laboratories that do test for pathogens will likely cost a good amount and in our opinion the cost doesn't really outweigh just replacing the plant (you could get another smoke bush for less most likely). There are a few soil labs for homeowners that do test for soil nutrients and acidity level amongst some other basic things and that is really the best for homeowners purposes. You can choose one from our website and follow the directions for sending in a sample if you are interested. soil  laboratories  To care for your struggling smoke bush, you can trim off the dead branches, and try to give it some balanced liquid fertilizer with nitrogen to help with what appears to be nutrient stressed leaves. Often branch die back can be caused by the roots not being able to take up the necessary nutrients the plant needs, either because of a disease like verticillium wilt or possibly the soil is lacking the necessary nutrients. It could also be stressed with the drought like conditions that we have had this spring.  You can refer to our webpage on Verticillium Wilt to read more about it. Plants can live with the naturally occurring soil born fungal disease for many years still if they are cared for; trim off the dead branches, make sure to supplement water as needed by feeling the soil first to see if the plants needs watering, and fertilize if necessary. Using mulch of leaf litter is beneficial as well to add organic matter back into the soil. As it breaks down that the plant can get nutrients from the decomposing matter and it will help retain soil moisture. Watering Trees and Shrubs Let us know if you have further questions with any of this information.  Emily

responder: The Question Asker Replied July 01, 2023, 9:02 PM EDT
response: Hi Emily,Thank you for all the information and recommendations as to how to treat the smoke bush. I am not surprised with what you wrote about the lab testing for pathogens. It would be helpful but, as you wrote, these can be expensive.I will trim off the dead pieces and get a fertilizer to make it feel better. Can you recommend any liquid fertilizer? Would this one be right:Monty's Plant Food Company 503160 Plant Vantage Premium Growth Fertilizer, 16 oz https://a.co/d/bn1TQMGThankfully, we finally started getting some regular rain here so there shouldn't be more stress from lack of water. If we get more drought, I will certainly be watering the poor smoke bush.If it happens that the bush doesn't make it, I shouldn't probably be getting another one for the same location, right? Can you let me know what other shrubs/ trees are vulnerable to Verticillium Wilt (or which aren't, if that's easier)? I wouldn't want to buy a different plant to have it go through the same stress and ultimately lose it as well.Thank you for all your advice!Best wishes,IzabelaOn Wed, Jun 28, 2023, 9:53 AM Ask Extension <<personal data hidden>> wrote:

responder: Answered by the Home and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied July 05, 2023, 10:54 AM EDT
response: Hi Izabela,  Any general balanced fertilizer would be fine. We can't recommend specific products or businesses, but anything with a lower dose of N-P-K, the 3 numbers listed for nitrogen, phosphorus, potassium, is good. Our Verticillium Wilt page states to not over apply Nitrogen so if you find a fertilizer formula that is lower like 3-3-3 that could be better. Just follow the label directions for timing of applications. You could also apply some compost around the base of the plant (or any of the other organic matter soil amendments- leaf compost, mushroom compost etc). You should eventually get a soil sample to see what the nutrient levels and pH acidity level is around the plant which would be beneficial for the long term.  You could plant another smoke bush in the same location, even though they may be prone to verticillium wilt, it usually is only affected when the plant is stressed anyways. Healthy plants that are in the right conditions don't typically pick up verticillium wilt. Necessary soil nutrients and consistent watering needs help to prevent a vert. wilt infection. It is also a common soil pathogen that is naturally occurring so relocating to a different area won't necessarily prevent it from happening. You can read some more information on our  Verticillium Wilt page that we previous linked in the first response. It has some tree species listed that can be more prone to it.  Missouri Botanical Gardens has a fairly extensive list of trees and shrubs that are susceptible to vert. wilt and a list of more resistant species as well.  Let us know if you have any further questions.  Emily

responder: The Question Asker Replied July 07, 2023, 6:33 PM EDT
response: Hi Emily, Thanks again for your help! It's interesting what you wrote about the possibility of planting another smoke bush in the same spot without necessarily having to suffer the same fate. I will remember that, just in case. The bed in which the smoke bush is gets a lot of leaf compost naturally. There are oaks and tulip poplars near it and we never clear the leaves from the bed. I will be supplementing with a fertilizer, just need to find the right formula.Thank you for all the information, it's super helpful!Have a great weekend!IzaOn Wed, Jul 5, 2023 at 10:54 AM Ask Extension <<personal data hidden>> wrote:

responder: Answered by the Home and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied July 07, 2023, 6:34 PM EDT
response: You're welcome!