By Torbobo
United Kingdom 
Hello,
I bought a beautiful Babylon Dahlia this summer and left it in its pot. It is now beginning to flower it's beautiful blooms but its leaves have been suffering from what appears to be some type if fungal infection? They have been drying out turning brown and curling up. It is happening from the plants base and gradually moving upwards.... The plant is now inside the conservatory with plenty of light but I noticed when it was outside it was covered with what looked like a fine spider web. I have been spraying it recently with diluted neem oil.
Can you help or enlighten me in any way as to what may be ailing it.
Many thanks and I look forward to replies.
21 Sep, 2013
Answers
Red spider mite definite. Possible bacterial or verticulum wilt. Cut that brown looking stem and see what colour it is inside.
21 Sep, 2013
Thanks for the replies.. The pot is quite large actually but I was going to repot or plant next year after flowering.
Red spider mite... Hmmm, how do I get rid of it please.
Thank you both for help.:)
21 Sep, 2013
Any insecticide spray which treats red spider mite will do, but your neem oil spray should already have taken care of it. Not sure about verticillum wilt - that's soil borne, so if you suspect that, dispose of the soil its in elsewhere and not in your garden. I don't think it is that - wish I knew where you lived, it may have been caught in an overnight cold snap recently. I can see a little new growth, so if that occurred after you brought it inside where its warmer, that might point to cold being a problem.
You haven't said just how big the pot is, but I still suspect it needed a bigger pot - this one gets up to 1 metre tall, and that requires a large pot (minimum 9 inches deep by 8 inches wide).
21 Sep, 2013
Ok, I shall repot it and keep spraying!
Thanks a lot :))
21 Sep, 2013
Can I ask how big is the pot you've got it in? Because it looks like the poor thing is stunted because of not enough root room for one thing.
21 Sep, 2013