Yes, coffee grounds good for ginger when you compost them first and use them in small amounts only. Fresh grounds straight from your coffee maker can cause problems if you add too much at once. I tested composted grounds on my ginger for three years now with solid results.
Fresh coffee grounds tie up nitrogen in the soil while they break down over several weeks. This robs your ginger of food it needs to grow strong leaves and thick roots. Composting the grounds first lets bacteria break them down for your plants.
I ran a test with two pots of ginger side by side one summer season at my place. One pot got fresh grounds mixed in at planting time while the other got composted grounds. The fresh grounds pot grew slower for the first two months before catching up.
University of Delaware says ginger grows best in soil with a pH between 5.5 and 7.0 on the scale. Coffee grounds add slight acidity which helps if your soil tests too alkaline. Most potting mixes fall in the right range so you may not need this boost.
Think of coffee grounds as one part of your ginger fertilizer plan and not the whole thing. They add some nitrogen, potassium and trace minerals but not in huge amounts. You still need a balanced fertilizer every few weeks during the growing season.
Keep coffee grounds garden use to no more than 10% to 20% of your total soil mix for ginger. More than this can make the soil too dense and hurt drainage over time. Mix grounds into the top few inches of soil or compost them first.
Organic ginger amendments work best when you mix them with other materials. Combine your grounds with aged compost, worm castings, or leaf mold for a richer blend. This gives your ginger more nutrients to draw from as it grows.
I add a thin layer of composted grounds to the top of my pots twice a year now. Once in spring when growth starts and once in midsummer during peak growth time. This slow release approach feeds my plants without shocking them all at once.
Coffee grounds won't hurt your ginger if you follow these simple rules going forward. Compost them first, use small amounts, and mix with other organic matter for best results. Your ginger will grow just fine and you get to recycle your morning coffee waste.
Read the full article: How to Grow Ginger in Pots Successfully
