All about plant fertilization

How and when to fertilize ferns


Ferns are very particular plants, especially since they do not contain seeds for their reproduction. As a decorative aspect, and since it does not generate flowers, the most striking thing is its leaves. Depending on the species, its leaves can have variations, both in size and shape. In general, they are widely used as a houseplant or also to decorate gardens. Given its popularity, we have decided to make a post on the use of fertilizer for ferns, how it should be applied, what seasons and more.

Fun fact Did you know that a fern fossil was found a few years ago? Its dating was between 350 and 390 million years old. Without a doubt, this is one of the oldest plants that still inhabit the earth. In addition, there are some species that after almost 200 million years have not had any type of evolution, growing in the same way as in those distant times.

1. What are the three numbers in a package of fertilizer?


Every maintenance task that you are going to carry out on a silver in your garden has secret or important information. When we talk about fertilization, it is important to handle some concepts such as nutrients and their importance for each plant.

In case you are thinking of buying a commercial fertilizer, there is a way to know at a glance the nutrient composition of a fertilizer. It is given by the three numbers separated by a hyphen that you can see in any package.

Those three numbers are known as the NPK values. Each of the letters represents one of the main nutrients, nitrogen, phosphorous and potassium.

Fertilizer for ferns
Outdoor ferns
  • N: represents nitrogen, which is the most important nutrient for leaf development, and is also the main chemical involved in photosynthesis.
  • P: represents phosphorus, being responsible for the development of roots, stems, flowers and fruits in a more vigorous plant.
  • K: this last letter represents potassium, nutrient responsible for giving more strength to the plant. Contributing to a better initial growth, giving greater resistance to diseases, reducing possible stress.

Understanding what each number is is very easy. It is the percentage by weight of each nutrient with respect to the total weight. To make it a little clearer, let’s develop a simple example. Suppose you have bought a 10 kg bag of fertilizer 16-5-11. In that case, you will have 1.6 kg of nitrogen, 5 kg of phosphorus and 1.1 kg of postasium. The rest of the total will be completed with other components and secondary nutrients.

Well, I think I was clear with the definition of the NPK value, so we are in a position to continue this article on ferns.

2. Growing ferns houseplant


As it happens with each and every one of the plants, it is not enough to fertilize it so that it develops healthy and strong. Because of this, and since we want to make sure you can give your fern the best it is, we’ll look at a list of the most important care you should take.

Please note that the following list does not follow any order of priority. Each of the following cares is as important as the previous and the following.

  • Lighting: they are used to developing in the shade of other plants. They cannot withstand many exposures to direct sunlight in a good way. This is one of the reasons why it adapts as well as a houseplant.
  • Pests and Diseases: With the same attention with which you inspect your home for damage, you should check your fern plants for possible pests or diseases. The most common and harmful pests for these plants are aphids and scale insects, which weaken them by feeding on their leaves. They are also susceptible to fungal diseases such as root rot and leaf spot, especially in excessively wet conditions.
  • Temperature: Most species do not resist frost or low humidity environments. If we must define an ideal temperature range, it is between 15 ° C and 24 ° C.
  • Irrigation: Your water needs for obvious reasons are higher in summer. Depending on the area, a couple of weekly waterings may be sufficient, in very dry areas they may need daily watering. Maintaining a humid environment is important. In winter, irrigation can be greatly reduced.
  • Pruning: although the fern is not a plant that has great pruning needs, it is a good ally to combat pests or diseases. Once any of these problems have been detected, it is best to cut off the attacked branches to prevent spread.
  • Fertilization: this point cannot be missing from this list. In the following sections, we will analyze in depth everything related to the fertilization of your ferns.

3. Best fertilizer for ferns (what kind to use)


Ferns are generally plants with few nutrient requirements. It is preferable not to apply any type of fertilizer before exceeding the dose. Therefore, you should be very careful when fertilizing your fern, as it is very sensitive to nutrient overdose.

Still, if you are going to fertilize, be sure to use the correct fertilizer. Preferably, it is best to use a slow-release fertilizer, which has a balanced mix of the main nutrients.

We have already seen in the first section how a fertilizer is defined from the NPK value. So you can imagine that when we talk about a balanced mix it means that all three numbers are equal.

In this case, it is very common to use a 10-10-10 or 15-15-15 mix. There are many commercial formats of fern fertilizers, with granules and liquids being the most widely used. The latter are highly sought after when it comes to potted indoor ferns.

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

3.1 Some homemade fertilizers

As with any plant, there is always the option of using homemade fertilizers. These have advantages such as low cost and disadvantages such as ignorance of their nutrient composition.

In ferns, choosing homemade organic fertilizers can be a good option. Especially if they are slow release. Let’s see some examples that you can do at home easily, quickly and cheaply.

  • Compost: this is undoubtedly one of the most widely used. It can be done with all organic leftovers produced in a home. Its composition is very heterogeneous, but in general it provides the three main nutrients.
  • Wood ash: characterized by being rich in potassium and phosphorous. It is best to apply it dissolved in water with irrigation.
  • Coffee beans: If you drink enough coffee at home, you can use the waste to apply it to your ferns. It is an excellent source of nitrogen.
  • Manure: This is another of the most popular home fertilizers. Its composition varies according to the animal from which it is obtained and its diet. It will always provide good amounts of nitrogen.
  • Earthworm Humus: If you can get Californian earthworms, they’ll take care of producing one of the best fertilizers for your plants. In addition to being efficient, it is more economical.

We could go on to mention various fertilizers, but this is more than enough for you to know that there are many alternatives. It is just a matter of knowing what nutrients each one provides. And make sure you don’t go too far.

4. Feeding ferns (How and when)


We have already seen which are the most important cares, what are the NPK values and some recommendations on the best fern fertilizers. It is time to learn how and in what way you should apply the latter.

That is coincidentally what we will see in this section. And for the sake of simplicity, we decided to divide the analysis between indoor and outdoor ferns. There are many differences when growing a plant indoors or outdoors in the garden. And those differences also have an impact when it comes to fertilizing.

4.1 Fertilizer for outdoor

When these plants grow in their natural environment, the environment is responsible for providing the necessary nutrients. If you can’t find the food, it will spread its roots, and will always receive the contribution of organic matter such as leaves, fruits and more.

Something similar happens when you grow ferns in your garden. So, unless the soil where it is planted is not very fertile, it will be enough to cover the soil with organic matter such as leaves, peat, bark from other trees, etc. This is undoubtedly the most natural way to feed ferns.

If you notice that the development of the plant is slower than normal, or that the leaves are less intense green, you can consider applying fertilizers. For cases like these, apply a 10-10-10 or 15-15-15 fertilizer, preferably a slow release one.

In general, it is best to do these applications during the spring, and always carefully read the instructions on the package. Every good fertilizer has clear instructions for its use. Never fertilize ferns in the winter.

In case you prefer to use homemade fertilizers, be very careful with the amounts you apply. Note that you don’t know the exact nutrient composition of fertilizers like these, so dosing can be tricky. If you have doubts, better apply less than more.

4.2 Fertilizer for indoor (Ferns in pot)

As with any potted plant, it doesn’t have the freedom or resources it would have if planted in the ground. In this case, it is up to you, the gardener, to supply your potted ferns with everything they need. Among these needs, of course, are nutrients.

Feeding indoor fern
Indoor fern

Like an outdoor fern, indoor ferns do not need large amounts of nutrients either, although they may require somewhat more regular supplies. If you notice that the development of the plant begins to be slow and / or the coloring of its leaves is not as intense as before, you may need nutrients such as nitrogen.

Deficiencies like that can be compensated with the application of a fertilizer, although many times they can be due to the pot becoming too small. A transplant to a new, larger pot and a soil change may be the solution.

If you have recently transplanted it, you should probably opt for fertilization. For this case, we will again use a balanced slow release mixture. These are 10-10-10 or 15-15-15. Typically, you will need this between the spring and summer months. Here we also discourage fertilization in the winter months.

Always be careful to water abundantly after fertilizing your ferns. This will ensure better nutrient distribution across all roots.

Lastly, remember that you can always opt for organic fertilizers like compost, manure, etc. But if you do, be more careful than using commercial fertilizers, as you don’t know exactly the composition (unless you do an analysis).

4.3 Fertilizing ferns with Epsom salt

The use of Epsom salt is widespread in gardening today. As we know, it provides minerals such as magnesium and sulfur, which are quite important for the development of plants.

In the particular case of fern fertilization, Epsom salt can be of great help to give more vitality to the plant, returning a better coloration on its leaves. But although it is repetitive, you must remember that these plants are quite sensitive to excess fertilizer. Therefore, you should only apply Epsom salts if you are sure you need it.

If you notice that the leaf coloration is turning somewhat yellowish, it may be a sign of a lack of minerals like magnesium or sulfur. Against this, you can apply a small dose of Epsom salts (mix one tablespoon per gallon of water and add with watering).

As a last recommendation in this section, you cannot avoid pointing out that the ideal, in plants as simple as ferns, is to know the composition of the soil. So if you can afford it, take a test to find out 100% what nutrients and minerals it contains. This way you will not fertilize blindly, making it safer.

5. Houseplant Fern care Guide (Video)


To end this article, we will leave a video (from the channel Garden Answer ), this will help you see more graphically what we have studied so far. It will certainly be more than good for you. 😉

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

And with this we have reached the end, I hope I have been clear especially when it comes to using fertilizer for ferns. And remember when you talk about fertilization, less is more. Since it is easier to solve problems due to nutrient deficiencies than excess nutrients.

Tags:  , , ,