Why would my hydrangea bloom green?

Walnut Creek, CA

Hi, Sorry this isn't in the hydrangea forum. I guess you have to be special and "subscribed" to post there. Feel free to move it if you can.

We have a hydrangea shrub that's been in the ground for about 3-4 years. The first year or two it was an amazing blue. Then last year the blue was faded and it the blooms were mostly green. Spring is here and they just started to bloom and they are green again! I applied an acidic fertilizer a while back but this plant is at my mother's house and hard for me to tend to it frequently. Why would the hydrangea plant be turning green? The leaves and overall look of the plant is very healthy. Great spring growth, nice deep green. I know the plants take a while to change their color so should I do anything now to help for next year's blooms? I'd like them to return to their striking blue. We have clay soil and they are in part sun. I did not do the planting personally but I belive it was planted with some store bought soil possibly some compost to break up some of the clay. Kinda of an awkward spot because depending on the season and the sun position they get more/less during the year. Could it have anything to do with their location?
Any suggestions?
Thank you!

Also, while we are on the blue hydrangea topic. I had heard that putting coffee grounds to help the acidity is a myth because once brewed the grounds lose the acidity. So I've heard of people pouring old coffee around the plant. Does anybody have any experience with this or think it would work? Just curious since there's almost always a little coffee left in the pot it would be a good way to reuse it.

This message was edited May 19, 2016 11:47 AM

Algonquin, IL(Zone 5a)

Cindy, I know Hydrangeas can start out green or fade to pale green, but until you mentioned yours I hadn't heard of Hydrangeas blooming green and staying green unless they were bred to have green blooms, like 'Limelight' or 'Annabelle'.

I searched online a little to see if there was a simple reason. I found the info below interesting. At the bottom of the article they mention a baffling condition caused by "Mother Nature" that could possibly be what's happening with yours. If so, don't worry. It supposedly only lasts a year or two.

http://www.gardeningknowhow.com/ornamental/shrubs/hydrangea/green-hydrangea-blooms.htm

In terms of coffee grounds or liquid. Coffee is great to put on your garden either on top or mixed in.

I save my coffee grounds, filters and all, and put them in my compost bin. Used coffee grounds only add a slight amount of acidity to soil, but it adds texture and other good stuff and best of all...worms love coffee grounds. It will actually draw them to your garden. There's really no downside. You can also sometimes get large amounts from places like Starbucks.

Here's a link to an old DG thread that discusses using coffee grounds. There's a lot of great info in it spanning years!
http://davesgarden.com/community/forums/t/707823/

As far as the liquid, if you have leftover coffee, go ahead and pour it on your plants.

Walnut Creek, CA

Thanks for your response! The strange thing is they were blue so I know they aren't the limelight type which is why it's so vexing. Hopefully they will change back to blue later in the season or next year. Last year they started out a faded blue then turned green pretty quickly after. Mother nature never ceases to amaze me!

I have put coffee grounds in my planting holes before to intice worms and break up the clay but I'll have to sprinkle some around the acid loving plants. Like I said I had heard that most of the acidity is brewed out of them so I didn't think it would help the pH much but I'll have to start mixing them into the soil to give those guys a boost. Good to know it actually will help the acidity!

Thanks!!

Walnut Creek, CA

I should have also mentioned that I'm in California so we just got over a drought. So last year I watered the hydrangea just enough to keep it alive. The year before that was similar, not enough water to thrive but enough to survive. Perhaps thats what cause mother nature to pull this little prank on me 😉

This message was edited May 20, 2016 9:08 AM

Glendale, CA

CindyC720 - growing up as a kid in Scotland (in the 1950s and 1960s), my parents put rusty nails in the soil on one side of hydrangea bushes and a copper source on the other side, and we had hydrangeas with inflorescences which ranged from deep red to purple to deep blue on the same bush ... in googling for support for that, I found
http://www.americanscientist.org/issues/pub/2014/6/curious-chemistry-guides-hydrangea-colors/ which says that it is simply caused by pH level ...

I don't grow hydrangeas myself, here in Glendale, because they need too much water (and are not edible), so I haven't done this, myself, recently ...

I hope this helps ...

Alasdair

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