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Fertilising your plants

What can we use to fertilise houseplants?

Every plant owner would have to understand the kind of fertilisers or supplements to give their plant at some stage. For me, it wasn’t easy and just as tough like for some of you. I would spend so much time reading and testing it on the plants before I find an answer. So I thought it will be nice to share some of my experiences. Before starting to list down the supplements I use to give the plants a health boost, I thought it will be useful to share with you on some of the jargons for example NPK, plant vitalisers/tonic and trace elements.

Don’t fret, it’s easy! If you already know what these are, just skip down below to the products I currently use. (This is not an advertorial and I do not receive a fee for recommending any of the products in this post.)


NPK otherwise also known as Nitrogen (N), Phosphorus(P), Potassium(K) is essentially what your plants need to grow. Without going back to the chemistry textbooks that we dislike, below is what you need to know when dealing with plant care.

Nitrogen (N): When you are trying to encourage growth of beautiful lush and green leaves in the foliage varieties, make sure this is higher in number than the others. Nitrogen will help with your plant’s leaf and chlorophyl development.

Phosphorus(P): Phosphorus will help with flowering, fruiting and root development. So when you have a flowering plant, you know what turns it on to get that full bloom.

Potassium(K): Potassium encourages root development too and an overall development of the plant.

So how do you read them? You will usually see numbers like 14-14-14. This just means an equal share or percentage of NPK in the fertiliser that you use. Most indoors plants will feel comfortable with this formula. You may like to do slight adjustments to that percentage if you have flowering plants or are at different stages of plant growth. For example if you are focusing on its root or overall development, you may want to increase percentage of Phosphorus(P) and Potassium(K). There are some in the succulent family like Haworthias and Cacti that need a high P and K too instead of N since they have leafy foliage.

Trace elements, nutrients for plants

These are secondary nutrients. Macro-nutrients like magnesium, calcium and sulphur help the plant to grow. And elements like Calcium helps the absorption of nitrogen intake. Look out for these in the fertiliser labels as they are equally important for growing beautiful, healthy plants.

Plant vitalisers or tonic.

Most plant vitalisers do not contain NPK but rather other plant extracts that help to boost the health of your plant. The formula really depends on the brand. A popular example used by many plant growers is HB-101 which is a formulation of extracts from age old trees like cedars and pines.

Fertilisers & Growth Products

Slow-released fertilisers

Osmocote 14-14-14

Type of Plants:
– Foliage Plants in the aroid family like Philodendron, Alocasia, Anthurium
– Flowering epiphytes like Hoya
– common houseplants like Rubber tree (Ficus Elastica), Spider plant (Chlorophytum comosum)

A balanced slow-released fertiliser is usually used for most indoor houseplants that need a consistent supply of nutrients for overall growth. Using a slow-released one reduces chemical burns since they are only released slowly whenever you water. They all have a coating that slowly breaks down over time, releasing the nutrients a little by little over a period of time instead of once in full intensity. I am using Osmocote because it is a popular brand in the US and seems to have the most effect for my plants. It can last at least 3 months.

Osmocote Plus Outdoor and Indoor Smart Release plant food 15-9-12

These Osmocote are also slow-released but they have a slightly different NPK to complement the trace elements in it. There are 11 extra nutrients in it that will help with plant growth. It is just so convenient and you will not need to top up the calcium and other nutrients separately. I will use this formula on plants that needs to be boosted for foilage and not so much its flowers since it has a slightly lower Phosphorus(P) count. And most importantly on those Aroids that I may forget to top up on the trace elements.

Osmocote 9-14-19

I am currently using this for my Haworthia and Cacti because it has a strong percentage of Phosphorus(P) and Potassium(K) that is good especially for their root development. I have some that came with very little roots and this ratio of osmocote helped very much in developing good strong roots and it also helps my Astrophytum to flower. I sprinkle just a little on it because it could be a little strong and I see some improvements in a month.

Worm Castings, Vermicast

There is no better way to say this but they are really worm poo or the end product from composting Earthworms’ humus. There are just so many benefits here. First, it helps the soil mix retains water with its crumbly spongy texture. But most importantly, the vermicast acts as a soil enhancer by enriching the soil and helping to break other organic matter in the soil, allowing for better absorption of nutrients. It also has a small amount of NPK and a generous bit of trace elements especially Calcium that helps in a plants absorption of nutrients. In this way, it works hand in hand with the fertilisers you use.

My plants also seem to have less nasty infestation from the bugs. And best of all, my Anthurium Crystallinum perks up straight after I feed it. You can sprinkle a good amount until it covers up the top soil as mulch or dig in after that like me with a chopstick to give it a good mix.

Plant vitalisers or tonic (HB-101) (Plantonic)

There are just so many of them out there and they all have different formulas and ingredients. I would go with the tried and tested. I am currently using the Japanese product HB-101 each time I water my plants and mixed about 3 drops of the concentrate for every litre of water. For me, they really work in the long run and works best at the overall development of the plant. I could see the roots of my plant grow really fast after a few weeks of using it, which is why I think many growers also use it on their Succulents and Cactus to push out those strong roots.

Another product that surprises me is the foliage spray, Plantonic. I could see an immediate effect on my aroids especially the Philodendrons the very next day after spraying. I use this by spraying on the underside of the leaves and also on their stems and soil. For the cacti and the airplants, I use it sparingly every 2 weeks. Spray on the cacti soil mix and for the Tillys, spray from the bottom up onto the leaves. But they really works best on the foilage plants. A word of caution though, overzealous ones like me will result in some yellowing of leaves if you overspray. Spray just enough till you see droplets on the leaves.

Below are supplements I like to try on the plants… STAY TUNED to this space for more updates.

Bone meal

What: An organic fertiliser that has a good source of phosphorus and calcium. Usually used in foliage plants like the Philodendrons, its NPK ratio usually reflects this (comes in ratios like 3-15-0). Bone Meal with its high percentage of phosphorous will help in the overall development of the plant as well on its flowering and because it has calcium, it will help the plant develop and better absorb nutrients. I will like to use this on my newly purchased plants that need to be potted and climatised. lol. I sound like a nutritionist.

Epsom Salts

Epsom salt helps improve flower blooming and enhances a plant’s foliage because it has magnesium, an important trace element that helps the plant absorb nutrients like nitrogen and phosphorus. I would love to use this on my Anthuriums and Dieffenbachias. The Dieffenbachias are very prone to this deficiency and when you see paleness and yellowing between veins of the leaves, you know he needs a magnesium boost. I currently have a sad one that looks like this.

( This is not an advertorial and I do not receive a fee for recommending any of the products in this post.)


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