I have been shopping for yews lately, and have noticed that many yews for sale in lower mainland nurseries have an orange or yellow colour. On another forum I was informed that this might be root rot, fungus, or both, along the lines of what is discussed in this document: http://ohioline.osu.edu/hyg-fact/3000/3060.html What remains unclear to me, however, is whether plants suffering such conditions can recover, and if so to what extent? Also, just how likely is it that this is an infectious condition - should one buy any yews in nurseries where some are discoloured?
We had 4 Taxus brownii planted on the north side of our house in an area where Rhododendron had died from Phypthothera root rot. One turned yellow as you describe and the usual Subdue treatment had no effect. I applied Messenger in a light spray and the plant responded quite quickly. A second application and the plant is back to the normal grean color and growing well again. Yes. I would be cautious about buying Yews from a source where the stock is yellowish. There are plenty of sources with healthy stock.
Thank you GRS. I asked in part because I did succumb to the lure of a Taxus cuspidata nana, which I hadn't seen elsewhere, and which does have a yellow cast to it that I didn't catch at the nursery where everything else was even yellower. Now I am uncertain whether to risk putting it in the ground or whether to quarantine it; whether to worry about what my garden tools or hands might transmit from it to the rest of the garden. If there is hope of recovery at least I don't need to be quite paralyzed with fear...
To get more information do additional reading on Phytophthora and related subjects (there are other water molds that affect nursery crops and ornamental plantings).
It's an anti-fungal, I take it? I haven't tried anything yet but decided to put the plant in the ground where it has good drainage, and hope for the best for now. I'll see what it does as growth begins in spring. Thanks for the follow-up.
I wouldn't: http://www.puyallup.wsu.edu/~Linda Chalker-Scott/Horticultural Myths_files/Myths/Harpin.pdf
Not steroids at all. It is natural chemical that triggers a gene that causes the plant to mobilize its immune system. It was discovered at Cornell University and has been very successful in cash crops like cotton, corn, etc. once Eden Bioscience was formed to produce it in quantity. It's understandable that they would address the major cash crop market first, but I'm glad to see they are packaging Messenger for home gardeners now. My garden was one of many that experimented to see what Messenger could do for ornimentals. I can see that some people are resistant to the advances of science, but do a google on it and learn the whole story before writing it off.
>My garden was one of many that experimented to see what Messenger could do for ornimentals.< What were your methods? Any controls employed? Earlier you mentioned spraying it on a single yew plant, which then looked better afterward so you concluded it was helped by the harpin. How many other yews from the same batch under the same site conditions did you spray it on? Did you leave half of them unsprayed (to serve as a control)?
The experiment was conducted on Rhododendron. Each cultivar had both control and applied treatment. The controls continued to decline; the applieds rejuvinated remarkably. The Taxus was not an experiment; just a desparation move after all else failed. It was remarkable. My test was only one among many I suppose. The sample was too small to be truly scientific. So go to Eden Bioscience if you really need proper test results. Or be courageous and try Messenger on a dying plant. What's to loose? By the way, where is the experimental evidence that "proves" other treatments will cure the problem with the Yew?
The heads up from Chalker-Scott (link, above) is enough for me to see that I don't want to undertake what has a good probability of being a waste of my time and money on it. I can tell from movie reviews which ones I would or wouldn't enjoy as well.
Let's see what Karin means by yellow/orange. How about a photo or two? Some of the root fumigants used to ward off root weevils and the like can cause the tree to have an overall yellowing effect. If the interior of the tree is green then we may be okay. If the yellow areas are dry and crisp to the touch then we may want to look at using a possible fungicide or a soil drench. We can see a light yellowing of the outer cast of the tree here with the advent of Winter cooling with shorter daytime light intensity. Check the color of the interior needles as that may tell us a lot. Jim
Just to clarify, the word "orange" in my original post referred to some plants that I did not buy - their colour was too extreme (and the plants were also mislabelled as to cultivar, which always annoys me). The one I did buy has quite a yellow colour, but the old growth is still green, now that you mention it. And it is possible that it has greened up a bit since I planted it - that's very subjective. I think I have attached photos - first try at this on this forum.
Thanks for the reassurance, GRS. They are a little yellower in real life than in the photo, though I really do think they are improving. I bought this at the same nursery that had some that were an outright flaming orange, though, and so questions like "how yellow is too yellow" were dancing through my head.
Karin, you did the right thing to ask and show photos of your tree. Your tree does not show signs of Phytophthora but does show a little needle cast on some of the newest growth. You will want to give this tree some water sprays when the temperatures warm to help with any scale you may have now and for the tortrix moth you might have later but the old growth which is what I would be more concerned with right now looks okay to me. No real problems with this tree so far from what I can see of it. Much of the overall yellowing you see and the slight discoloration of some of the tips of the old growth needles is due cooling temperatures and to some extent combined with less light intensity. It is normal for the youngest growth to be a lighter colored yellow-green than the older growth will be. I do have a suggestion that you try to keep the planting area for this tree free of other Conifer debris for a while. Jim
Thank you for taking such a close look, Jim, and for the detailed explanation. Ah yes, the conifer debris... that is from the huge thug of a conifer overhead that I am hoping my neighbour will take down soon. They did just very kindly limb the thing up some 10-20 feet, which is why the debris is a little excessive at the moment.
