Fertilizing with Coffee?

[JanS]

I wouldn't use coffee grounds for orchids: coffee is acidic and some grounds can have a very low pH which orchids generally don't care for. On the other hand, the acidity is good for some other plants like azaleas, blueberries, etc. which can benefit from coffee grounds worked into the soil around them.

As far as the killing snails bit, a couple of years ago I had a huge problem with little snails that got into my orchid pots through some plant(s?) I bought and proceeded to devastate my collection. I read up scientific literature on the use of caffeine to kill snails and the dosing - which is so much higher than can be achieved with coffee itself that using coffee or spent grounds (which have even less caffeine) makes no sense. So I bought several bottles of No-Doze (the pharmacy cashier was giving me weird looks ), dissolved them to proper concentration, used a home-made centrifuge to spin out the chalk from the pills..and watered my most affected orchids with the liquid.

If it had any effect at all, it was minor and temporary (and expensive since I spent over $20 on No-Doz to get enough liquid for just a few pots). So my advice is - DON'T BOTHER! Even the scientific papers note that effects vary from 50-70%. If you have a snail problem and need 100% snail death (who doesn't?), watering your plants with a malathion (back on the US market) solution was the only answer that worked for me.

I did notice my caffenaited orchids shaking a bit uncontrolably after that treatment, though...