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Niobe Clematis has some yellowing leaves #875998

Asked July 05, 2024, 12:12 PM EDT

Can you tell me what is causing the yellowing of some of my Niobe Clematis leaves while some of the other vines have green leaves but not real dark green? Thank you

Oakland County Michigan

Expert Response

Hello Pam,
It's very difficult to try to diagnose this problem without more information. Could you give me some information about the plant? 

How old is the plant? How do you care for it---water, fertilizer, mulch? Have you seen any insects on the plant? Is it planted in sun, part-sun, or shade? Do you see any wilting of the leaves?

With the warm, wet conditions this past spring, we have received many calls about yellowing and brown spots on the leaves of plants. This condition has caused fungal diseases and root/crown rot. If you could send me close-up pictures of the plant in question and the problem areas, I may be able to give you a more complete answer.  

The following links give important information about clematis. The first is from Clemson University, which explains how to care for clematis. The second link, from Penn State University Extension, describes diseases that may affect clematis.
https://hgic.clemson.edu/factsheet/clematis/
https://extension.psu.edu/clematis-diseases

I'm sorry I can't be more specific, but if you send other pictures and more information, I'll try to give you a definitive answer.

Have a good day. 
I bought the plant from Bordines Nursery about May 9, 2024 and I believe they said the Clematis were about 2 years old.  The tallest vine was probably 2' tall when purchased. I planted them (2) Niobe Clematis about May 16, 2024 in a bed containing Flower Tone and Bone Meal.  I used Myke on the roots at planting.  I had used a moisture meter to check the moisture which the majority of the time seemed to point to very dry - so I added a lot of water.  I am always afraid of over watering but when the meter says, "Dry" (far left on meter), I add a lot of water. I just don't understand why the meter is almost -  not always - saying "1" in the "Dry" area.  Should I water even with all the rain we have had?
 
The plant is on the South-Easterly of the house.  Sun from sometime in the morning until maybe 3 pm or so.
 
I have not seen "wilted leaves".  We have in-ground sprinklers and the water is hard water to my knowledge (I don't think the outside water is connected to the water softener).  I see some of the leaves on the right Clematis plant much more than the left Clematis plant (2 plants) that start out green and slowly some of the leaves change coloring with some brown speckling, etc.
 
I added some Organic Phosphate as instructed related to a May 2024 soil test.  I have also used the Epsoma liquid Tomato fertilizer (1 cap per gallon of water on each plant about every 2 weeks).
 
Regarding insects on plants - I haven't seen any but there has been something making holes or chewing on leaves that are up the trellis.  I have also seen very small flies.
 
I have attached a couple pictures - sorry if blurry - I am not a good photographer.
 
On 07/10/2024 11:14 PM EDT Ask Extension <<personal data hidden>> wrote:
 
 
The Question Asker Replied July 11, 2024, 12:15 PM EDT
Hello Pam,
Thank you for the additional information. 

Since I can't see a view of the whole plant, I can't tell if this plant has clematis wilt, which is a serious disease of clematis. You would need to have the plant diagnosed. It does show signs of nutrient deficiency, though. You may not be using the correct fertilizer. Read the articles below to see what fertilizers are recommended and how much to use.  

The leaves do look as if there is a watering problem.  Overwatering and underwatering are two main reasons that plants fail. When newly planted, they need to be watered every day. But once established, plants need about 1 inch of water a week or a little more in drought conditions. You also need to factor in the amount of rainfall each week. This year, there has been ample rain in some weeks to satisfy the 1 inch requirement. 

I do think you should cut back on watering for a while. Your clematis may be suffering root problems.  Remove all yellow leaves and clean up all leaf debris to prevent fungal diseases. Clematis likes cool feet, which means that you should use a good amount of mulch around the root zone. 

The following links give great information on growing clematis. They also include important information on fertilizing your plants. I think you will find them helpful.
https://extension.oregonstate.edu/news/clematis-climb-special-place-garden
https://hgic.clemson.edu/factsheet/clematis/

About your water meter: If you have had it for a while, make sure to clean the tip after each use and never leave the meter in the soil for a long time. Try scrubbing the tip lightly with a steel wool pad to remove any corrosive parts on the tip. Finally, check other areas in your garden to see if the meter reacts the same way. There may be a problem with the meter. 

I suggest that you remove all affected leaves and clean up any debris around the plants. Reduce watering and fertilizing. Observe the plants to see if they stabilize. You may not notice any improvement right away because plants often struggle in their first year. However, if the plants continue to decline, you may want to have the problem diagnosed to determine if it's clematis wilt. Oakland  County Extensions has diagnostics available (Phone: <personal data hidden>) or you could send a sample to MSU diagnostics at www.pestid.msu.edu for a fee. You can also take plant samples (a section of the affected vine) and pictures of your plants (not just the leaves) to Bordine's and talk with the plant experts there.

I hope this information helps, but don't hesitate to contact us again if you need further information or have more questions.

Good luck with your Clematis!
Here is a picture of the whole Niobe Clematis.  I stopped watering about a week ago because we are continuing to have rain, at least some, almost every other day. 
 
I looked at your 2 website links and neither seems to address my particular problem (as I do not have black leaves). They get plenty of sun and there is mulch near the roots. I may be fertilizing wrong and I may have watered a little bit much after first planting.  I also think I need to have the plant diagnosed.
 
Where would I go to get the plant diagnosed?
 
Thank you
On 07/17/2024 1:06 PM EDT Ask Extension <<personal data hidden>> wrote:
 
 
The Question Asker Replied July 17, 2024, 4:41 PM EDT
Thank you for sending a picture of the whole plant. It is truly beautiful and looks healthy for a newly planted clematis, but I understand that you're concerned about the leaves continuing to turn yellow. 

As I said in my previous message, you can send a sample to campus at www.pestid.msu.edu. I believe there is a fee for their services. You can bring samples to Oakland County Extension in Pontiac. They do diagnostics on certain days, so call first to see when they are available at <personal data hidden>. And, I would also try Bordines and talk to one of the experts there. Bordine's usually warranties their purchases, so I believe they would be able to help you determine the cause of the yellowing leaves.

Let me know if you need more information.
Thank you:  Oakland County Extension in Pontiac, Michigan is close.  I will look at that.
On 07/17/2024 5:41 PM EDT Ask Extension <<personal data hidden>> wrote:
 
 
The Question Asker Replied July 17, 2024, 5:50 PM EDT

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