I have annually tall non-blooming beautiful hydrangeas. One is partially shaded under a pergola and the other in full sun......the later of the two is somewhat larger. I keep them watered and fed with acid fertilizer ( miracle grow}. They generally do not bloom and if they do it is not prolific. I would like to know if there are any suggestions about pruning trimming and feeding. I am in planting zone 6A Southern Indiana. These plants have a western exposure.

jonny - is your MG acid fertilizer 30-10-10? Might be too much nitrogen to get good blooming. Do you know what type of hydrangeas you have? That will determine when you can prune them. I'd back off on the fertilizer for now, especially going into fall.

I do not know what type of fertilizer or hydrangeas I have. These plants are in my elderly neighbors yard which I maintain for her. She has not told me much about them. I do know that they have been in the ground for many years.....I have been with them so to speak for ten years. I was wondering abouth the excess nitrogen and the lack of blooms. I know that the MG is a generic acid meant for azaleas and rhododenron plants as well as the hydrangeas.......I will check the content is the ratio you listed in your responce the correct one or is it too high in nitrogen. Is there a reference of photos which I could refernce to be able to identify the hyrdrangeas I am dealing with I could describe the mature plants if this would help.

What colour are the flowers when they do bloom, and have you pruned them in the last year? For the most part shrubs don't need very much fertilizer so I agree with Cindy to stop fertilizing them at least for the rest of this year, although that may not be why they aren't flowering. I assume they are planted in the ground and not in a container.

Yes in the ground and they are never given food after spring......the blooms tend to be non existant on the full sun plant and have a range of colors when on the partially shaded plant. That range of colors are: blooms which are white tinged in green as if not fulling havinng come into into any particuar color and blooms which are pinkish white, and bluish white on more than one occaison I have seen all three of these color schems at the same time on this plant.

Does it look like any of these?

http://www.hydrangeashydrangea...

Or

https://www.google.ca/search?q...

Jonny - sweet of you to help out your neighbor. How does the foliage (leaves) look on the two shrubs? Do the branches die all the way down to the ground in winter or do the previous year's branches grow new leaves in the spring? I know - lots of questions but it does help us try to figure out the problem.

You folks have shown me that these plants are the hydrangea macrophylla. The stems are long and remain thru the winter with them only producing very little new growth. I leave/left those stems with new green shoots and do not cut out the barren woody stems which show no growth and are dry and brittle until there leaves on the remaining along with many new long stems with very good growth. I had previously said that had applied MG acid food when in fact it was Shultse's 32-10-10. Applied twice one month apart in the spring. I would like to say that I appreciate all of your responces.

You might try protecting them in winter and during early fall cold spells and spring freezes. SInce most Hydrangea macrophylla flower on the previous year's wood the buds can be damaged by cold weather before they get a chance to flower. There are some macrophylla types that will flower on the current year's wood but we don't know which ones you have.

You asked about pruning, trimming and fertilizing. Is that to try and get flowers, or are they too big for their location? For flowering you need to leave them pretty much alone except for removing dead branches, and in your zone they may benefit from winter protection.

I make all these inquiries so that they will flower. I will do the protection bit this fall........they are not too large for the location(s). What is the best for protecting such a large plant....each of them is just over a cubic 1.5 yard

It might be a good experiment to skip next spring's fertilizer applications to see if that high nitrogen level is inhibiting flowers. You could try spreading a thin layer of compost under the shrubs instead.

There are suggestions for winter protection here:

http://www.hydrangeashydrangea...

Regarding the fertilizer, it's not just the analysis but also the amount. A little bit of high N won't have the same impact as a large amount with the same analysis. Having said that, since the flowers are formed on the previous year's wood the buds are already there (or not) by spring so fertilizing then wouldn't make any difference I'd have thought. I actually don't fertilize hydrangeas at all but I can't grow the macrophyllas because it is too cold here and don't know what their demands might be.

Sue - good point about the fertilizer. Compost wouldn't hurt though. I don't feed my hydrangeas either but, like you, I've given up on the H. m. here.

Not to hijack another person's non-blooming hydrangea thread.... but it caught my eye because I am having the same problem, yet I don't fertilize the hydrangea. I have one bloom this year. The hydrangea was given to us by family member, so I don't know or recall the type that it is. It came to us blue, but has pink blooms. (I think I remember believing it was Nico Blue, but I could be completely wrong.)....I keep adding coffee grounds to the soil to try to raise the acidity level to get it to turn blue, but apparently that plant is determined to be pink! One pink bloom. ONE. And it's pink! (I usually try to avoid pink flowers.) It has been there for 3 years now, I believe, I feel like it should have a lot more than one bloom. It had atleast two blooms when it was a tiny plant about 1/5 the size. It is about two and a half or 3 ft tall now, and equally wide, so it is a fairly well-established plant. It gets morning sun but mid-day shade. Thoughts on why it might not be blooming well?

You're at the limit for Hydrangea macrophylla also, of which 'Nikko Blue' is a cultivar. So the flower buds that formed the previous year are vulnerable to being killed in cold weather in fall/winter/spring. If you want to be bothered, try giving it winter protection. Also it shouldn't be pruned (other than dead branches).

Coffee grounds unfortunately are not necessarily acidic and certainly not acidic enough to turn a hydrangea from pink to blue. You need something more "serious" to lower the soil pH. The blue depends on aluminum so you can try aluminum sulphate which is sold in garden stores but simply lowering the pH sufficiently by other means may be sufficient.

The ground coffee you buy in the store is acidic...after you prepare your coffee, the resulting grounds are near-neutral in acidity.

I like the idea of adding compost around the base of the plants. Hold the fertilizer. Make sure they have enough sun and water. Winter protection if needed, burlap and a few lengths of rebar should be enough (?) and hold off pruning.

Good luck and hope you see blooms next year.

Thanks, Sue and Greene! I did do enough research in the last few months to find out that coffee grounds barely have any acidity, but hadn't researched enough on exactly what would give me a better acidity, not did I know what was affecting the bloom count, so I really appreciate the suggestions!

Compost n burlap. Will let you know how things go next year

Good luck!

Thanks!