September 6, 2013
A trick for making your soil better for tropical plants
What tropical plants want is acidic soil. The native soil here in the desert is exactly the opposite, alkaline. No, I have no idea about ph numbers, or anything like that. All I know is that coffee grounds help to acidify soil. And tropical plants love it!
Luckily, you can get all of the coffee grounds that you want to for free from your local Starbucks. They usually have some wrapped up and sitting around. I ask at the counter for the largest bag they will give me. The last time I was at the Starbucks at 75th Avenue and Thunderbird, the cheerful young man went and got a HUGE bag of coffee grounds, double bagged. I gave him two bucks and told him to buy a cup of coffee (although that wouldn't be enough). The bag of coffee ground was very, very heavy, so be sure that you can lift and carry before you ask for it in quantity.
And this is what you do: Take it out to your garden and dump it. Spread it around. I've been doing it for so many years now that it has become part of the soil now. Worms crawl through it. I suppose you could get down on your hands and knees and try to mix it all in, but I never do. I am always adding a new layer of mulch (supplied to me free by my two olive trees) and regularly adding more potting soil. So the soil at The Tropical Paradise, while not as acidic as if I were in Hawaii, is not as alkaline as regular Arizona soil.
To review: Tropical plants like acidic soil, coffee grounds help to acidify the soil, and you can get all of the coffee grounds that you can carry away for free from your local Starbucks. There, that's all the chemistry that I need to know!
By the way, your garden will smell like coffee for a few days. Not unpleasant, but it will go away as the coffee grounds break down.
Posted by Brad Hall