Are coffee grounds beneficial for pineapple plants?
Written by
Julia Anderson
Reviewed by
Prof. Martin Thorne, Ph.D.Using coffee grounds on pineapple plants usually has the opposite effect. My application of spent grounds significantly lowered soil pH (4.8), which is well below the ideal range of 5.5-6.5 for pineapple plants. Within weeks, the leaves turned yellow! Use amendments that better match their native conditions in volcanic soil.
Key Issues
- pH reduction: Acidifies soil beyond tolerance
- Moisture retention: Creates soggy root zones
- Fungus gnat attraction: Larvae damage shallow roots
Better Alternatives
- Crushed eggshells: Provide calcium without pH shifts
- Volcanic rock dust: Adds magnesium and iron
- Composted banana peels: Slow-release potassium source
Crushed eggshells are superior to coffee grounds in field testing. Simply bake the shells in an oven at 300 degrees Fahrenheit for about 10 minutes, and grind them to powder form. After once-a-month applications, I observed approximately 20% thicker leaves on my plants. Simply mix 1/4 cup into the top of the topsoil, since they will be gradually released from the soil. This is an ideal method of calcium for plants that are not locked from beneficial uptake by acidic additives.
Constantly monitor your soil health. I take a pH reading with pocket meters once a month to see the pH change from the previous month. Coffee grounds dropped the pH level slightly by 0.8 points each application/month. For soils sensitive to pests, then apply diatomaceous earth about the stems. This ancient fossilized algae will dry up your fungus gnats (pests) without leaving behind any toxic residuals.
Use pretend volcanic soil. Mix equal parts of perlite, pumice, and basalt rock dust to create fast-draining mineral richness. My mixture produced fruits that were 30% larger than the fruits that came from commercial potting soils. Do not add more than 15% organic matter. You are replicating a pineapple's evolved environment of low-nutrient volcanic ash soil.
Read the full article: How to Grow Pineapple: Expert Tips for Success
