Hi, I have a lot of hicks yews. They’re in their third year now (of being planted in our yard) and haven’t gotten any more water than usual this summer, but a few here and there have been going light green. I thought they might be yellowing and on their way to dying but they’ve stayed this light green colour for many weeks now. They seem to be fruiting quite a bit also. Not sure if that’s related.Are they just holding on and about to die or is this something else?
Dear gardener, thank you for contacting the Toronto Master Gardeners regarding you Hick’s Yews.
You bring a very interesting case. Hick’s Yews (Taxus x media ‘Hicksii’) are tough and easy maintenance evergreens as long as they are grown in well drained, medium moisture soils. Light green needles are quite common in the spring and are a good sign of growth however, by your description, this seems to be have started in early fall.
You did not mention what area of the city you are located in. Is your soil heavy clay? Are they planted in a low lying area or near a spout? On the other hand, if your soil is sandy and acidic it can influence magnesium absorption. Needles can turn yellow in very acidic soils (pH 4.7-5.4) or very alkaline soils (pH over 7.5). Soil salinity may also influence how nutrients in the soil are absorbed.
Although watering has been maintained normal, Yews do not like ‘wet feet’ (this is commonly due to poor drainage). Soil compaction, heavy clay soils, overly rainy periods all contribute to this condition. Under these circumstances they may begin yellowing, dropping needles, and lacking vigor. If the conditions prevail, the yellowing intensifies and gradually they begin turning brown. As often happens, when a plant is in distress, secondary pests or diseases move in.
Insects and diseases could also cause needle discoloration. Look at the base of the needles for insects or fungi black fruiting bodies on the affected needles. See Yew problems and Yew pest and diseases for reference.
For more information on care of yews, please see the following links:
http://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?kempercode=f870
https://www.bartlett.com/resources/plant-health-care-recommendations-for-taxus.pdf
Please do not hesitate to contact us should you have further inquiries.