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My neighbor said I was killing my hydrangeas with coffee grounds, and he was right | Botany Lovers - Discusd

My neighbor said I was killing my hydrangeas with coffee grounds, and he was right

My neighbor Dale, who has been growing hydrangeas in Portland for like 20 years, told me last spring to quit dumping my used coffee grounds around the base of my blue hydrangeas because it was making the soil too acidic. I ignored him for two months because I thought coffee grounds were supposed to be good for plants from everything I saw online. By July the leaves were yellowing and I got maybe three blooms on a bush that used to be covered, so I finally stopped and switched to a basic 10-10-10 fertilizer. This year the same bush has around 15 blooms coming in and the leaves look way healthier. Has anyone else had coffee grounds backfire on them, or did I just use way too many?

2 comments

2 Comments

umabailey25d ago

Wait, your neighbor told you this and you ignored him for TWO MONTHS? That is wild to me. The man has been growing hydrangeas in Portland for 20 years, that is basically a hydrangea PhD in my book. I get it though because everything online says coffee grounds are a magic fix for soil. The part that shocks me is that it actually changed your bloom count that much, from three blooms to fifteen is a huge jump. I always figured coffee grounds were pretty mild and you would need a ton to really mess things up, but maybe that is the trick, people dump way too much thinking more is better. Sounds like your soil was already on the acidic side and the grounds just pushed it over the edge.

olivers2825d ago

The part about "everything online says coffee grounds are a magic fix" is the real problem here, because most of those articles leave out that grounds are still acidic until they break down, and that takes months in a cold climate like Portland. Nobody ever mentions your tap water either, since Portland water runs a bit alkaline and some folks are basically fighting their own soil chemistry without knowing it. Dale probably knew all that from watching his own beds for 20 years, which is worth more than any blog post.