How and when to fertilize spinach
Spinach is the vegetable par excellence, being possible to cultivate even the smallest garden. Currently, with urban gardens that are very fashionable, it is very common to see it cultivated inside apartments, balconies or any corner of the house. It is a very good source of very important minerals such as iron, potassium, antioxidants and vitamins such as A and C. In this post we will analyze how to apply fertilizer for spinach, in what way and when to do it and some of the most important care.
Table of Contents
1. How to grow your spinach
If you are looking for information on how to fertilize spinach, there is no doubt that you have a crop of this vegetable in your garden. So I want to help you with some quick tips on how to use this crop in the best way.
- Soil: prefers soils with a good amount of nutrients and humid. On the other hand, they do not develop very well in acid soils, they prefer them with pH values between 6 and 6.5.

- Sowing: as they need little heat to grow, it is advisable to sow in autumn or early spring. The seeds should be placed at a depth of about 2 cm. In general, a large number of seeds are placed, so if germination is good it is usually necessary to clarify leaving a distance between plants of at least 10 cm.
- Sun: depending on the temperature they can grow in full sun, although in very hot places it will be better to place them in semi-shaded places.
- Watering: Although they like the soil to remain moist, it is not good to water too much. It should never cause waterlogging as it can cause problems like root rot.
- Harvest: when you start to harvest, keep in mind that you can start pulling leaves little by little. Try to avoid uprooting the whole plant, so that the crop will yield much more.
- Fertilization: this will be the subject of our article, so in the following sections we will see in depth how and when to carry it out.
2. NPK values – What do they mean?
We have already left the care of the spinach behind. It’s time for us to talk about how to use fertilizers for this vegetable. But first I need to explain an essential concept when analyzing the fertilization of any plant. And by this I mean NPK values.
I have no doubt that you have seen a bag of commercial fertilizer on more than one occasion. If so, you will have noticed that on his forehead there are almost always three numbers separated by a dash. These numbers are known as NPK values. Each letter being the initial of the three most important nutrients in the development of a plant.
- Nitrogen (N): favors the growth of the aerial part of the vegetables (leaves, stems). It is, in part, responsible for the green color of plants and confers resistance to pests.
- Phosphorus (P): it is very important in the ripening of flowers, seeds and fruits. It participates in the formation and development of roots and has an important role in resistance to drought.
- Potassium (K): it is decisive in the development of the whole plant, it allows the roots and stems to be strong and the seeds, fruits and leaves, large. It provides resistance to pests and diseases, aids in the circulation of other nutrients around the plant, and regulates the functions of the plant.
On the other hand, each number specifically indicates the percentage by weight of the nutrient with respect to the total weight of the fertilizer. Since I know this may not be entirely clear, let’s look at a simple example:
“If you have bought a 5 kg bag of 10-15-20 compost. This compost contains 500 g of nitrogen, 750 g of phosphorus and 1 kg of potassium. The remaining weight is taken up by minor nutrients and other components.”
With this I think you should have no doubts about these numbers. Now we can go ahead and get fully involved with the fertilization of the spinach.
If you are reading this post, you will probably be interested in learning about fertilizing these other plants.
3. Best Fertilizer for spinach (requirements)
To develop properly, spinach needs good amounts of nutrients. Among the most necessary is nitrogen. Let’s see below what are the best commercial or homemade fertilizers to use in your spinach crop.
As I always like to remember, you must be careful with the doses of fertilizer that you are going to apply. This is mainly due to the fact that it is easier to solve a nutrient deficiency problem than problems related to excess fertilizer.
3.1 Organic fertilizer (homemade)
Ecological cultivation is becoming more fashionable every day, which obviously must be done avoiding applying all chemicals to your plants. This means that you will have to avoid any chemical fertilizers. Faced with this, it is best to go to homemade fertilizers made at home.
Among the most common and simple organic fertilizers for spinach that you can make yourself we can mention the following:
- Fish emulsion: place a fish in a large container with a lid along with three parts of sawdust, a bottle of sulfur-free molasses and a little water. Then stir and turn every day for 15 days until the fish falls apart. Once the decomposition is done, you can use the fish emulsion diluted with water. The usual ratio is one tablespoon of emulsion to one gallon of water.
- Manure: there is not much secret to preparing this compost. It is only important to point out that for its use it must be correctly fermented. Otherwise, it can cause problems for the spinach.
- Compost: there is no doubt that it is one of the most complete and economical organic fertilizers to make. At the same time, use all the organic matter that we dispose of at home. Like manure, it should be used when decomposition is 100%.
- Compost tea: as its name suggests, it is a “tea” that is made from compost. To do this, put a good amount of compost in a burlap bag and let it sit in water for about 20 days. By then the water will have turned yellow and can be used for fertilization. If the yellow is very dark (almost brown), dilute it in water until it is light yellow.
- Bone flour: to prepare it, bones are placed on the fire and left to burn until they are brittle (this usually takes a couple of hours). Let them cool and place them in a sturdy bag or sack, then use a utensil to grind them until they turn into flour.
We already looked at homemade fertilizers, it’s time to check out some of the best commercial fertilizers.
3.2 Commercial fertilizer for spinach
Within commercial fertilizers there is a wide range that can be used. In general, it is recommended to use those with high levels of nitrogen, which will stimulate further development of the plant. In any case, there are those who successfully use balanced fertilizers, that is, with the same proportion of the three main nutrients.
If you are going to use balanced fertilizers, a 10-10-10 mix is one of the most used. Then you can add nitrogen with some other fertilizer (eg urea). In case you prefer to use a mixture with higher nitrogen concentration directly, you can use a 15-10-10 mixture.
Regarding the format, we will see in the next section that depending on certain conditions they can be used in both liquid and granulated formats. You must be careful when applying either one.
4. How and when to fertilize spinach
It is best to start with the use of spinach fertilizer before planting. This is to adapt the soil to the high nutrient requirements of this vegetable even before it has been planted.
For this you can use a balanced granular fertilizer, or apply some organic fertilizer rich in nitrogen (ex: compost, esitercol). Do this several days before transplanting, thus allowing the nutrients from the fertilizer to have already begun to dilute into the soil.
When the seedlings have properly taken root, you can start fertilizing with a liquid fertilizer. Preferably a mixture of 15-10-10. This fertilization must take place throughout the spinach development cycle. The regularity with which it must be done is 15 or 20 days. Carefully read the instructions for use of the fertilizer, there you will find the most appropriate dose to use.
There is also the possibility of using granulated fertilizer, replacing the liquid. If so, apply it laterally to the edge where you have the spinach planted. Be careful not to leave fertilizer grains near the seedling stems, otherwise they can burn your plants. Remember to also accompany the fertilization with abundant watering.
You can change some of the commercial fertilizers with an organic compost. During the development of the plant it is preferable to use water soluble organic fertilizers, such as compost tea, fish emulsion, etc.
5. Spinach Crop Using Organic Fertilizer
As we always do, we will dedicate this last section to a video (from Simply Garden & Home channel) where you can graphically review many of those seen so far. I have no doubt that it will be useful to see it and if you can please like it. 😉
We have reached the end of this article, I hope you have no doubts and know how to use fertilizer for spinach. Remember that any questions you can always visit our website or contact us.
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