Question
Hello Melissa,

I live in Dallas - and my query is about my Coreopsis Sunray Shrubs. I bought them, early spring and have them planted as a border to my plants. At first - the flowered beautifully. We had a lot - a real lot of rain (not complaining - just stating facts) this spring. Coreopsis did just fine - loads of blooms - lots of compliments. For the past some time - I've noticed that - the new buds in the plant - dont open. They just turn brown. I have the odd flower open in each shrub. There are loads of buds - but they just turn brown and dry. The leaves look just fine - a few bottom ones have a whitish patch on them. The plants are mulched.
I'm not sure - if I'm dealing with some sort of fungus. Or is it crown rot? I dont want to do more harm - esp since the temps are almost 100F+ everyday.
One more observation - 2 sprinkler heads - have part of the spray hitting the shrubs. Dont know if that is responsible. The sprinklers are on once a week - mostly early morning.
Please help.

Farah

Answer
Dear Farah, I too live in East Texas, and I know how much rain we had all early summer, as well as how hot and dry it has been for the last month or two.  And I had a similar problem with my coreopsis this year, although it was a different variety.  I think you do probably have a fungal infection that has been giving you these problems.  The other possibility might be spider mites.  To test for spider mites, tap some of the leaves or affected parts of a plant sharply over a white sheet of paper.  Tap sharply several times, then observe the paper.  Do you see things moving around?  If so, you have spider mites.  The GOOD news is that whether you have a fungus or a mite or even an insect pest, you can control them all with NEEM which is an excellent product to always have on hand.  It is organic, can be used on just about anything, and gives good results.  Look for any product with the active ingredient Neem in it.  The BAD news is that the heat has been so intense that it will be hard to spray this without the possibility of damaging the plants a bit.  I think your best bet would be to spray Neem in the early morning hours before the heat is bad.  Also, make sure that you have removed all spent blooms as well as any duds that failed to open.  I don't think the sprinkler issue would be the problem unless the mulch is up into the leaf area and stays wet constantly.  In that case you are almost cooking your plants.  Hopefully, these will do better once the heat has abated somewhat.  It is hard for plants to flower in extreme heat.  Make sure they are well watered at least once, probably twice a week, more if less established, deadhead all dud or spent blooms, spray with the Neem and they should be better.  If not, then perhaps they have been able to reseed and you might have more plants coming up later.  I hope I have helped answer your question.  Please write back if you have more questions.  Good luck, Melissa