Using food leftovers as organic fertilizers certainly has its good and bad sides. I’ve noticed it grows in popularity, year by year. Many people asked me, “isn’t using food leftovers such as coffee grounds, banana peels, and eggshells more natural?”.
But what exactly isn’t natural about standard fertilizers? Everything in them is just extracted from natural sources and concentrated for greater effect, which is exactly what food leftovers lack when used as fertilizers.
However, to claim that food leftovers aren’t beneficial fertilizers would be simply ignorant. I actually use them occasionally because they aren’t as strong as regular fertilizers.
There are dozens of pros and cons, some of which are opposite depending on if we are talking about in-ground or potted fig trees.
Let’s dig a bit deeper into the topic.
Using Food Waste as Fertilizer for Potted vs. In-Ground Fig Trees
Potted fig trees: Food scraps won’t degrade quickly enough on the surface of your pots. Therefore I wouldn’t use unfinished kitchen scraps to mulch potted fig trees. The soil in pots lacks the things that would break down organic matter. Eggshells might work okay. Everything else would either not degrade properly or start molding.
Even worse, it would attract worms and flies. You don’t want to have to deal with mold on a fig tree, especially.
A solution I would recommend is running organic stuff through a worm bin first. Alternatively, drying food waste in the sun and blending it almost into dust.
In-ground fig trees: I don’t see a problem with in-ground fig trees. Worms will be attracted to it, aerating the soil and producing worm castings around the roots.
I would recommend tucking the food waste under the mulch not to dry up and compost more quickly because it is wet. But that’s a little more effort. Also, don’t use too much coffee waste directly in your garden because it can block the soil, restrict aeration, and reduce soil drainage.
To put it another way, make sure it’s spread out and doesn’t totally cover the surface.
Are Coffee Grounds Good for Fig Trees?

Pros:
- Slightly acidic
- Good carbon and nitrogen source
- Source of Mg, K, Na, P, Al, Fe, Ca (Low quanitites)
- Can be used more often
Cons:
- Low amounts of nutrients for fig trees
- Needs to be used together with other fertilizers
- Stops soil drainage if not scattered enough
- Leads to mold which can be dangerous for fig trees
Coffee grounds provide some, but not all, of the nutrients that plants require. They are fairly mild towards a fig tree and could save you some money.
The nitrogen they provide is useful only for the growing season and doesn’t help fruit in any way.
Putting coffee grounds in the pots is not a good idea. That is a perfect setting for mold to grow. It would be better to use it for in-ground fig trees. Even then, I’m always careful not to put coffee waste too close to the tree trunk.
As far as acidity goes, the common argument is that they lower soil pH levels. However, the great majority of acidic components from coffee grounds have already been removed at that stage. The acidic effect is so mild that every other quantity-related issue about coffee grounds will appear before you see any reasonable pH reduction.
Larger quantities can actually increase pH because of chemical processes that happen in the ground.
When talking about in-ground fig trees, you can mitigate all the cons if coffee waste is used with care.
If you throw large lumps of wet coffee waste in your garden somewhere where they can stay damp, you’ll observe a lot of molds. I normally dry the grounds in the sun before scattering them over the ground or incorporating them into garden soil.
Someone could be mistaken and think that coffee grounds are enough as the only fertilizer. However, that’s completely wrong. I know many people recommend it, and they are not wrong for doing so, but coffee waste is far from adequate fig tree fertilizer.
Nutrient and mineral quantities aren’t that high. It needs to be used with some other complimentary stuff because high quantities of coffee waste cause the issues mentioned above.
Nutrient chemical components of coffee grounds:
Mineral component | Value (%) |
---|---|
Ca | 0.37 |
Mg | 0.14 |
K | 2.49 |
Na | 0.04 |
P | 0.18 |
Mn | 0.01 |
Al | 0.58 |
Fe | 0.29 |
Organic component | Value (%) |
---|---|
C | ~ 44.87 |
N | ~ 1.69 |
Lignin | 28.6 |
Cellulose | 30.4 |
Hemi-cellulose | 14.9 |
Tanins | 0.4 |
Are Eggshells Good for Fig Trees?

Pros:
- Rich source of calcium
- Can be used for potted fig trees as it doesn’t attrack pests or mold
Cons:
- Calcium isn’t required by younger fig trees
- Eggshells lack any other beneficial nutrients
Eggshells are a great source of calcium. In my opinion, using eggshells together with other food waste as fertilizers completes the picture, especially with coffee grounds and banana peels.
To make them effective, I crush them into tiny pieces. There is no need to make them into dust like some other food waste, and you don’t need to dry them. Eggshells are the least harmful, if even at all, to fig trees.
They slowly dissolve as you water your fig tree and release calcium. You don’t need to worry about coffee grounds attracting pests or mold, making them viable as fertilizer for potted fig trees.
However, younger fig trees don’t need that much calcium. It’s enough to use eggshells once and then repeat more frequently as the tree matures.
Are Banana Peels Good for Fig Trees?

Pros:
- Source of potassium, phosphorus, magnesium, and calcium
Cons:
- Not ideal for potted fig trees because it attracts pests
- Low nutrient quantities
- High pH levels
I think banana peels are the worst out of these three food waste fertilizers. Personally, I didn’t use them for years, and I don’t remember any results, but many sources claim banana peels help a lot. They are probably right since fig trees need potassium, and potassium sources are rare.
The only problem is that the amount of potassium a large fig tree needs equals about a thousand banana peels. But then again, fig trees can thrive with pretty scarce nutrients.
If I were to use them today, I would allow the banana peels to dry out on concrete or bricks until they are black and crispy. After that, grind them into a powder in a food processor or spice mill. Alternatively, I would pass them through a worm bin first.
Nutrient chemical components of banana peels:
Nutrient | Value (%) |
---|---|
Protein | 3.5 |
Sugars | 31 |
Calcium | 0.8 |
Magnesium | 0.2 |
Potassium | 4.6 |
Phosphorus | 0.3 |
Conclusion
All in all, these three work together well as food waste fertilizers. Each on their own is simply not good enough for fig trees. As a regular fertilizer for someone who isn’t too worried about their fig trees, coffee grounds, banana peels, and eggshells make a good alternative to regular fertilizers.
However, I’m still keen on pointing out that fig trees, like any other, will show you specifically what is wrong with them. Regular fertilizers are way more concentrated and can be used as quick fixes for certain problems. While food waste fertilizers, unless you can gather and compost them in huge quantities, won’t be able to solve your tree’s problems very quickly.