Question
QUESTION: I have a new garden with 11 tea roses from a reputable seller. I have 4 plants that have leaves turning black or dark brown in large swaths (not spots) and not yellowing.  The underside of the leaves look ok and there is no other apparent damage. I can't find a picture or anything that will identify this for me.  Help!

ANSWER: I wonder if it could be too much fertilizer as that will cause leaves to turn brown. The other that damages leaves is a spray for disease or insects. Some roses will not tolerate certain sprays. Can you get back to me and tell me if you have sprayed your roses?

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QUESTION: Thanks for answering so quickly.  I have used Immunox for roses as directed about once every 2 weeks.  Leaves aren't really turning brown.  They stay green with irregular patches of really dark green or black, with no pattern.  It seems that more of these leaves are toward the top.  When I planted them I put in some worm compost as recommended (about 1/2 C per plant).  They are out in the open with good circulation and all day sun.  Thanks again

ANSWER: If your roses are Tea roses and not Hybrid Teas, then certain sprays will cause a discoloration of the leaves as the plant is re-acting to the problem caused by the chemicals in the spray. Also Immunox cannot be sprayed on a rose when the temperatures are hot. Actually you can cause problems by spraying anything when the temperature goes over 75'. Dark green coloration on roses can be a lack of a chemical such as phosphorous, but if you are using a rose fertilizer than most of them contain enough to correct the problem.

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QUESTION: Hi, Lynnette.  I did a soil test that indicated the PH was right where it should be for roses, and that there is plenty of potash.  If I didn't make an error, it appears that the Nitrogen and Phosphorus levels are very depleted.  The leaves are somewhat better---I switched to dust and bought a water meter so they don't get over watered.  However, some leaves toward the bottom are still turning yellow and then brown and falling off, and the blooms are very small.  Next item.  What do I do when we have a huge rain--anything?  And, what instructions should I give to someone who will take care of my garden when I am away for 2 weeks?  Thanks!!

Answer
Rain doesn't harm roses and as there is nothing you can do about it, I would try not to worry.I get concerned when gardeners are told to use chemical sprays too often. Fungicides should only be used when you see evidence of an infection. Insecticides should only be used when there are insects on the plants not as a preventative. Immunox is a humdinger of a spray and could be described as a powerful one, so every two weeks I think is too much for roses. I would pull back on the spraying (I am not an organic gardener) but I think your roses are not happy with so much of the Immunox because of the discolouration and small blooms. For someone looking after your gardener, if they picked up the yellow or dead leaves and put them in the garbage and water very well every three days, your roses should be fine.