Some fiddle leaf fig owners add coffee grounds to their fiddle leaf fig plant to help it grow.
But is coffee good for fiddle leaf fig plants? What happens to the soil when you add coffee grounds to it?
Why People Put Coffee Grounds on Plants
All plant owners want to give their plant the best love and nutrition it needs. It feels good to do something productive with your used coffee grounds.
Some believe that adding acidity to the soil is beneficial to the plant. This is true, but only for specific acid-loving plants like rhododendron, hydrangeas, and camellias.
Coffee also contains nitrogen, which is a component of many plant fertilizers. This ingredient leads many to believe that adding coffee or coffee grounds may help their fiddle leaf fig.
Risks of Using Coffee on Fiddle Leaf Fig Plants
There are risks to using diluted coffee or coffee grounds on fiddle leaf figs.
Directly applying coffee grounds to indoor plant soil can cause excessive moisture retention, fungal overgrowth, and impair plant growth due to over-acidifying the soil.
Without a complete compost and decomposition system, along with proper drainage, the grounds themselves will build up and can restrict the airflow to the soil. This in turn will foster gnats and grow mold in the soil.
Acidity and Plants
To know more about how coffee can affect your fiddle leaf fig plant, it is important to understand acidity and your plant.
As soil breaks down, it results in excess acidity. There is always the tendency for potted soil to become more acidic over time, so you have to work to keep yours alkaline.
This is one reason it’s easier to grow great hydrangeas in pots, especially if you live in an area where the soil is more alkaline.
I use an alkalinity filter as the final stage of my water purification system. This is after a whole-house water filter, softener (only necessary if you have very hard water), then an under-sink reverse osmosis filter to add alkalinity to all of my plants for this reason.
Do Ficus Plants Like Acidity?
Generally, acidity is helpful for acid-loving plants like azaleas, hydrangeas, camellias, and blueberries.
But ficus are not acid-loving plants!
Ficus trees like neutral pH soil conditions (slightly acidic or slightly alkaline). If the pH falls far out of this range, ficus trees may have difficulty absorbing nutrients from the soil.
The perfect pH for a ficus is 6.5-7.
Anything under 6 will be too acidic.
Brewed coffee has a pH of from 5.2 to 6.9, so depending on the coffee, it could be harmful to your fiddle leaf fig.
Signs of Too Much Acid in Fiddle Leaf Fig Plants
Plants will sicken or die if the soil becomes too acidic for their needs. Yellowing leaves is the most common sign of too much acid in the soil.
Too much acidity in a fiddle leaf fig can be confusing, because your plant will show all the same symptoms of being under-fertilized, even if you are fertilizer properly.
What happens is a pH of under 6 causes your plant’s roots to be unable to absorb the nutrients in the soil. Yellow leaves, stunted growth, and unhappy plant are the general symptoms.
An Example of Too Much Acid in a Fiddle Leaf Fig
This fiddle leaf fig has terrible yellowing leaves which could easily be mistaken for just needing fertilizer.
A quick pH test however shows the potting mix is a pH of 5 when the ideal range is 6.5-7.
You should check the pH of your soil at least twice a year. Use our fiddle leaf fig soil meter to test the moisture, pH and light of your fiddle leaf fig.
How to Correct Soil That Is Too Acidic
Repot your plant and water normally with a well-balanced fertilizer for a fiddle leaf fig.
If repotting isn’t possible, you can use alkaline water drops to make a batch of alkaline water and thoroughly water your plant.
Once you have repotted your plant, continue to monitor its health and check to ensure the leaves are growing properly. For a schedule on fiddle leaf fig care, be sure to check out this fiddle leaf fig care calendar.
Nitrogen, Caffeine, Coffee, and Fiddle Leaf Figs
But what about adding diluted coffee to your fiddle leaf fig to give it nitrogen, caffeine, and other nutrients? Check out this before-and-after photo from one of our Fiddle Leaf Fig Facebook Community members.
Coffee grounds are approximately 1.45 percent nitrogen, which may be helpful, but it lacks significant amounts of other important nutrients like magnesium, potassium, phosphorus, and calcium.
It’s possible that a good watering and a tiny boost of nitrogen and caffeine (as well as attention) could give your fiddle leaf fig a growth boost. But over time, your nutrient mix can become off balance, which can cause long-term deficiencies in your plant.
Never add cream and sugar to your coffee before giving it to your plant.
Watering with cool, diluted, black coffee once in a while is fine if your plant seems to respond well.
To learn more:
- Sign up for our free Fiddle Leaf Fig Care 101 Webinar or our free Fiddle Leaf Fig Course, and make sure you’re subscribed to our newsletter.
- Download our free Propagation Guide
- Read The Fiddle Leaf Fig Expert, your complete guide to growing healthy fiddle leaf fig plants. The book is available in full-color paperback or Kindle edition on Amazon now!
- Join our Facebook Community and chat with other fiddle leaf fig lovers.
Grab the Essentials for Your Fiddle Leaf Fig:
- Premium Fiddle Leaf Fig Potting Soil
- Fiddle Leaf Fig Plant Food
- Root Rot Treatment to treat one of the most common issues affecting fiddle leaf figs.
- Houseplant Leaf Armor to protect against insects, bacteria, and fungus (As an added bonus, it also cleans and adds shine to your plant’s leaves!)
- Moisture meter to always know when your plant is thirsty.
- Houseplant Propagation Promoter to propagate more quickly and with more success.