All about plant fertilization

How and when to fertilize rhubarb plant


Rhubarb is a plant that is closely related to celery. It is cultivated as a vegetable for its edible stem, which has a very characteristic acid flavor, being highly sought after to prepare sweets and desserts. It can grow up to three meters in height with stems that can reach 5 cm in diameter. Although it is not one of the most popular vegetables worldwide, in the United States and the United Kingdom its use is very common. That is why we dedicated an article to talk about the use of rhubarb fertilizer, how and when to apply it and what type to use.

Fun fact: Although the stem of this plant has a rather unique flavor and is highly sought after by cooks, did you know that its leaves can be poisonous? Remember this and always discard its use in any recipe in your kitchen.

1. NPK values – what does it mean?


We will start this article by talking about a concept you need to understand to use fertilizers. And no matter what plant you are going to fertilize, you will always find that on the fertilizer packages there are three numbers separated by a hyphen. Do you know what those numbers are?

If you know you can skip this section. Otherwise we will clarify that question here. These numbers represent what is known as the NPK value. These letters are the initials of the three main nutrients that help the development of a plant.

Fertilizer rhubarb
Rhubarb plant
  • 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.

There are many more nutrients and minerals that bring different things to your plants, but these are considered the most relevant.

Understanding what each number is is very easy. It is the percentage by weight of each nutrient with respect to the total weight. In case it’s not clear yet, let’s look at an example.

Suppose you have a 10-kg pack of 15-10-20 fertilizer at home. In that case, 1.5 kg of the total are nitrogen, 1.0 kg is phosphorus and 2.0 kg are potassium. Pretty easy don’t you think?

2. Feeding rhubarb plants


Although this post is about fertilizing rhubarb, the truth is that this plant, like everyone else, needs more than fertilizer to feed. Since from our website we want to make sure that your rhubarb feeding is correct, so that it develops healthy and strong, it is that we will see several cares that you must take into account.

2.1 How to care your rhubarb?

For many tasks it is necessary to be an expert before doing them, for example you would never start to fix the water pipes in your house or you would never repair your car if you are not a true expert. I have good news, to grow rhubarb you don’t need to be an expert, just follow these simple tips:

  • Climate: Although it adapts very well to a very wide range of climates, the truth is that it needs enough of the winter cold. These especially stimulate the edible stems to acquire a more intense red color, something highly sought after to attract attention.
  • Planting: in relation to the need for cold, it is best to plant rhubarbs in autumn. Therefore, we do not make sure that it has many cold hours in the winter, and then, at the end of the frost, it begins to develop.
  • Soil: The ideal soil for this vegetable are those with good drainage and a large amount of nutrients. Never try to plant it in clay soil. On the other hand, the pH should remain around 6.
  • Irrigation: It is good to keep the soil moist, but you should never produce puddles when watering. Always maintain a watering with some regularity, being greater the need for water in the development seasons such as spring and summer.
  • Flowering: When the rhubarb begins to emit flower stems, they are detrimental to the development of the foliage. That is why you must remove all the flower stems, thus ensuring better production of the edible petioles.
  • Fertilization: Fertilization can not miss on the rhubarb care list. In the following sections we will deal with delving into this topic.

2.2 The best rhubarb fertilizer

Although it is not too demanding on the ground, if you are looking to optimize rhubarb cultivation, it is better to carry out certain fertilizer applications. Being the most recommended to make a mixed use between commercial fertilizers and organic fertilizers.

If we are talking about commercial fertilizers, and since you already know what the NPK values ​​mean, you should use one with a balanced mix for your rhubarbs. This means that all three numbers are the same. In general, most gardeners recommend a 10-10-10 fertilizer. Although other mixes like 15-15-15 also work correctly.

A 10-10-10 fertilizer is very common, adapting to a large number of plants. It’s best to buy it in a slow-release granular format, allowing nutrients to reach the soil little by little.

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

If we talk about organic fertilizers, the one that is best adapted to be applied in a horaliza like rhubarb is guano. It can be of any animal such as horse, cow, rabbit, etc. All of these are an important source of nitrogen.

Finally, during its cultivation, a mulch of organic matter can also be applied to the soil. This will help maintain moisture, maintain a more constant temperature, and smother weeds at the base of the rhubarb.

3. How and when to fertilize rhubarb?


We started by talking about NPK values, then we saw some basic recommendations for cultivation and the best fertilizers for rhubarb. It is time to learn how and when to fertilize.

What we will recommend here is a fertilization with commercial inorganic fertilizers and homemade organic fertilizers. Thus we will take advantage of each of these types of fertilizers.

You can start fertilizing after winter is over, and with your rhubarb starting to sprout. We will use a 10-10-10 mix of slow release fertilizer. It is widely used, so you will not have problems obtaining it in any nursery.

At the time of applying this fertilizer, do it in an approximate amount of 1/2 cup per plant. Extending it circularly around the plant and applying a good irrigation. The latter will help the fertilizer to be distributed in a better way. You can repeat this fertilization in late summer.

Depending on the characteristics of the soil, you can reinforce fertilization by applying manure (must be rotten well, don’t use fresh manure) in mid-spring or early summer. If you notice that the plant developed correctly, with a lot of vigor, you can do without this fertilization with manure.

Advice: Whichever fertilizer you use, always be careful not to apply it in contact with the stems of this vegetable. Leave a few centimeters away, this will avoid burning the plant. Also always remember that when it comes to fertilizing more in less, it is better to fall short than to exceed the dose.

In the first days of autumn it is the best time to apply mulching. This will allow maintaining a more constant soil temperature, maintain humidity and suppress the possible growth of weeds.

As a last tip on the use of fertilizers for rhubarb, I should point out that you should always read the instructions on the package of the fertilizer. Every good fertilizer has clear instructions for its use. If you are going to use it in combination with organic fertilizer, you can use lower doses than those recommended in the instructions.

4. Rhubarb fertilizer (video)


To end the article, we have selected the following video (The channel “The Wisconsin Vegetable Gardener“) . In it you will see how to carry out the fertilization of rhubarbs, in this case grown in pots. You will see that a 4-6-4 fertilizer will be used here, which in addition to the mixtures that we have recommended here, also works very well.

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

And so we have reached the end of this post, I hope you found it useful. And when you grow rhubarbs, don’t hesitate to fertilize them.

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