Can someone help ? my rhododendron won't blossom..?

I live on the Puget Sound Peninsula and have lived in this place for going on 3 years and there are big rhododendron's with buds but won't flower. Any ideas?

Can someone help ? my rhododendron won't blossom..?
Please read these two links:





http://landscaping.about.com/cs/treesshr...





http://www.rhododendron.org/subsequentca...
Reply:Attached is a good answer - here are the salient points from it (the querent is in Detroit, so it is close to your zone - I am betting your plant needs to be burlapped during the winters and I expect it still might be too cold up there for your variety):





"Low temperatures. The buds could be flower buds that FROZE during the winter and in Detroit this could easily be the problem. Cold climates are too cold for many rhododendrons. Most rhododendrons have a low temperature at which the flower buds are damaged and will not produce flowers. It varies greatly from variety to variety. You may need a hardier variety like PJM.





Nutrients. Improper nutrients my be a problem that affects cold hardiness and flower bud set. A few things you can do are to fertilize with phosphorus (super-phosphate) per directions to increase hardiness and flower bud set. This can be done any time. Do not use nitrogen rich fertilizers as they may inhibit flower bud production and also reduce cold hardiness. Lawn fertilizers are notoriously high in nitrogen and should be kept away from flowering plants.





Acidity. Measure the pH and acidify if necessary. Since your plant looks healthy, this is probably not the problem. Flowers of sulfur (powdered sulfur) is the best chemical to use to increase the acidity [lower the pH]. Do not use aluminum sulfate since aluminum salts build up in the soil and eventually becomes toxic to many plants including rhododendrons and azaleas. If soil is too acid, the symptoms can be the same. Very acidic soil can prevent the roots from taking up nutrients. As many of my rhododendrons are planted in very acidic forest soil, an application of Dolomite and a light topdressing of mushroom manure in late spring is all they need. Sprinkle the lime on in late winter, very early spring. Don't overdo it - just a light sprinkle. If it is mid-spring, get the lime on right away so the rhododendron roots will be able to take up the soil nutrients in time for new growth. If you don't have rain, water it in well.





Protection. If the plants are wrapped in burlap during the winter, they may gain a few more degrees in hardiness.





Drought. When soil moisture is too low, the buds will not open. Watering will usually resolve this condition if detected soon enough."