All about plant fertilization

Best fertilizer for Agapanthus – [How and when to fertilize]


Agapanthus is a plant of African origin, also known as Lily-of-the-Nile or the African lily plant. They have long leaves that form an intense and very compact foliage. But the attractiveness of these plants is not his foliage, but his flowers in intense or white blue colors, gathered in Umbelas of 20 to 30 flowers. These flowers begin to appear in the last days of spring or the first days of summer. The cultivation of these plants is simple, so they will not demand a lot of time to take care of them. In this publication, we will analyze everything about the use of fertilizer for agapanthus, how and when applying the fertilizer and more.


There are several agapanthus species, including deciduous and perennial leaves, and there are also many hybrid species. It is very important that before planting an agapanthus know if it is deciduous or perennial, this will allow you to cultivate it better. Keep in mind that these plants have rhizomes, so its reproduction is usually quite simple.

Fertilizer for agapanthus
Interesting fact: if we make an etymological analysis of the word agapanthus, we see that it arises from the Greek words ‘Agape’ and ‘Anthus’. Translating These two Greek words gives us a meaning of “flower of love”.

1. What is the best soil for Agapanthus?


Before asking you how I should fertilize my agapanthus plants, there is a question you should ask yourself. This question is what is the best soil for these plants. And it is useless to fertilize correctly if the land in which it is planted is not correct.

Agapanthus do not like the soil to be wet for too long, so it is best to look for soils with good drainage capacity. A mixture with a good percentage of material such as sand, perlite or pumice stone is a good option. This will allow the soil to drain quickly.

The soil must not only drain well, it also needs to have a certain amount of nutrients. For this it is good to add compost, which will provide a large amount of nutrients. A mix of 60% compost and 40% sand will work well.

2. Main nutrients for Agapanthus


As we just discussed, the soil must have nutrients, but what are the nutrients that agapanthus will benefit from? The truth is that, like all plants, they absorb many nutrients. But in a few words we can summarize all its needs in the following three nutrients.

  • Nitrogen: without a doubt this is one of the most important nutrients for most plants. And it is essential for the development of both stems and leaves. If you see that your agapanthus grows very slowly, it may need a little more nitrogen.
  • Phosphorus: phosphorus is a nutrient that is present in many important plant processes. Among these processes we can mention photosynthesis, nutrient transport, protein synthesis, carbohydrate decomposition, energy transmission, etc. In a practical way you should know that this nutrient helps the development of roots, generation of fruits, seeds and flowers. It will also help your agapanthus overcome many illnesses.
  • Potassium: the third of these nutrients also plays an important role in processes such as photosynthesis, translocation of photosynthesis, protein synthesis, enzyme activation, among others. In summary, we can ensure that it helps the development of strong stems with a good growth rate, as well as increasing resistance to periods of drought and the presence of any disease.

As we will see in the following sections, it will be enough for you to provide these three nutrients during the fertilization process so that your agapanthus is strong and healthy.

2.1 What are NPK values?

You already know something about the nutrients that these plants need, but in the next section we will start talking about fertilizers, and for that you will need to understand what NPK values are. This will help you find the right fertilizer for your agapanthus.

NPK values are three numbers separated by a hyphen (they have this format 10-15-20). What these three numbers indicate is the concentration of the three main nutrients in a fertilizer (nitrogen, phosphorus and potassium). You will see that on the front of the fertilizer packages you will find these three numbers. That way you will know which one to buy.

Let us understand this concept a little better with a simple example. If you buy a 10-10-10 mix, it indicates that it is a mix that we know as balanced. This is because it has an equal concentration of all three nutrients. 10% is nitrogen, 10% is phosphorous, and 10% is potassium. Balanced fertilizers are widely used in agapanthus.

If you are reading this post, you will probably be interested in learning about fertilizing these other plants.

3. Best fertilize for Agapanthus


There are a large number of fertilizers both on the market and homemade fertilizers. But for the fertilization of agapanthus we will see that we can carry out a fertilization plan using very few types of fertilizers.

Within the commercial type fertilizers, that is, those that you must go to buy at a nursery, the agapanthus as balanced fertilizers. Among the most useful balanced mixes are 10-10-10 or 14-14-14. As long as they are balanced they will be useful, at a higher concentration you will only need to apply less amount of fertilizer.

On certain occasions it may also be useful to use phosphorus fertilizers, that is, with a higher proportion of phosphorus. This is because this nutrient helps a better flowering. For this reason, it may be useful to have a 10-20-10 fertilizer on hand.

It should also be clarified that within commercial fertilizers there are many formats. Above all, we can divide them into those that release nutrients quickly and those that release them slowly (which can take several months). In the next sections we will see that, depending on the occasion, both the quick release and the slow release will be useful.

If you have to mention a useful homemade fertilizer for agapanthus, you can not miss the compost. This is not only very easy to do, but it also helps to give extra use to all the organic waste in our house. It also provides a large amount of nutrients to the soil.

4. Fertilizing Agapanthus


We already talked about what are the characteristics of the soil that agapanthus need, what are the most important nutrients and what fertilizers are the most useful. It’s time to analyze when and how you should apply these fertilizers.

4.1 When to fertilize

Agapanthus are plants that do not resist low temperatures very well. When winter arrives they will go into a dormant stage, so they will not need to be fertilized during these months. It will be on the hottest days when they begin to need some fertilizer.

Especially in those agapanthus that are grown outdoors, you should completely suspend any fertilization plan in mid-autumn. If you grow them indoors you can afford to pay a few more days, since the plant will not be exposed to so much cold. In any case, it is good to let your agapanthus rest during the winter.

Once the first days of spring arrive, it is when you can start fertilizing. This will give it a boost to start generating new stems, leaves and flowers during these months. You can extend the fertilization until late summer or early fall.

4.2 How to fertilize

Depending on how you grow your agapanthus, the fertilization plan has some small variations. That is why we will analyze separately the fertilization of agapanthus grown in pots, and those that you grow outdoors.

4.2.1 Potted agapanthus

In these cases, fertilization begins at the time of selecting a suitable soil mix. As we said, it is good to use compost in the mixture that you are going to use for your agapanthus. Then you can continue fertilizing with balanced liquid fertilizers.

In early spring apply a balanced 10-10-10 fertilizer. It is always advisable to read the instructions for use that come with the package. But we will use half the concentration of fertilizer when we dilute it in the water. After paying accompany with abundant irrigation.

Extra advice 1: if you notice that the flowering of your agapanthus is not being the most abundant, it is good that you apply a fertilizer with a higher phosphorus content. To do this you can substitute one of the balanced fertilizer applications for a 10-20-10 fertilizer.

It will be enough to pay once a month. Although we have already said it on several occasions, it is good to remember that this fertilization plan must be carried out during the spring and summer. Come autumn, you will no longer need to fertilize your agapanthus.

4.2.2 Outdoor agapanthus

For agapanthus outdoors we will use balanced fertilizers again. This can be one 14-14-14 or 10-10-10. The difference in this case is that we will opt for slow release fertilizers.

Depending on the slowness with which the nutrients are released, the number of applications that we must make during the season will vary. You will find fertilizers that release their nutrients in 3, 6 or even 12 months. It would be good if you choose to use fertilizers with a release of no more than 6 months.

Extra tip 2: never use fertilizers with too much nitrogen concentration (for example: 30-10-10). Especially if you use it in the first days of spring, it will make the plant more concerned with generating leaves and stems than with flowers. That is to say, you will have very good foliage, but the flowering is more scarce.

As always, fertilization must be accompanied by good watering. And as in the pot agapanthus, we must cancel any fertilization in the cold months of autumn and winter.

5. Video about fertilizer for Agapanthus


To end this post, and as is always the custom in this blog, we have selected a video (MyGreenLawn channel). In this video you can review several of the concepts seen throughout our article. I hope you find it useful. 😉

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