All about plant fertilization

How and when to fertilize dahlias


Dahlias are a genus of plants in the Asteraceae family, whose origin is Mexico (where it is also considered the national flower). Among the species that make up this family are herbaceous and shrubs. Although there are differences between each species, all are characterized by producing beautiful flowers. That is the reason for its great popularity around the world. And for this last detail we are forced to dedicate an article to it, where we will talk about how to use the fertilizer for dahlias, how and when to apply it.

Fun fact: In ancient times, the Aztecs cultivated these plants not for their flowers, but to use their tubers as food. This particular use gradually disappeared over time, especially with the Spanish conquest of the new continent.

1.How to care your dahlias plants?


While this article is primarily about using fertilizer for dahlias, from here we want your plant to grow as healthy, strong, and beautiful as possible. That is why before we start talking about fertilizers we will see a list of the most important care that must be carried out.

  • Light and location: When choosing a location for your dahlias, look for one with good lighting and ventilation. Anyway, if where you live the sun is too strong it is preferable to place them in a semi-shade.
Fertilizer for dahlias
Dahlias flowers
  • Climate: although the ideal climate for these plants is temperate, it also supports heat and low temperatures and frosts down to 5 degrees below zero. If you live in an area with even more intense frosts, try to protect the plant from this cold, as it can kill even the bulbs underground.
  • Soil: they like soils rich in organic matter and with good drainage. When transplanting, be sure to move the soil well so that it is well porous and easy to drain.
  • Pests: in general they are quite resistant to the attack of pests and diseases. Although we cannot fail to mention that their worst enemies are aphids and snails. Regular checks of your plants will help you catch any attack from these insects in time.
  • Irrigation: on summer days, with the highest temperatures of the year, they need regular and abundant watering, although there is no flooding. Try to wet the soil, not the plants and much less your flowers.
  • Fertilization: the fertilization of dahlias could not be missing from this list. Keep reading until the end, in the following sections we will delve into this point.

2. NPK values of a fertilizer


Talking about fertilizers is talking about nutrients, because in order to identify one fertilizer from another it is necessary to know what nutrients it is composed of. To easily and quickly recognize a fertilizer, so-called NPK values ​​have been defined.

These values, which you will typically see on the front of any fertilizer container, are three numbers. Each number is the percentage by weight of the nutrient with respect to the total weight of the fertilizer. And will you say what nutrients each number has? The letters NPK represent the three most important nutrients for a plant.

  • Nitrogen (N): favors the growth of the aerial part of 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, helps the circulation of other nutrients around the plant, and regulates the functions of the plant.

So, now you know that if you buy a 10-20-30 fertilizer, 10% of the total is nitrogen, 20% of the total is phosphorous, and 30% is potassium. Pretty easy, don’t you think?

3. Best fertilizer for dahlias


There are many types of fertilizers that can be helpful to apply to dahlias. Choosing which one is right depends on many factors, such as the age of the plant, the desired result, or even the taste of the gardener.

Below we will detail some of the best fertilizers for dahlias, we will stop to analyze four different situations and fertilizers. Then it will be in your hands to know how to recognize which of all the options is best suited to your particular situation.

3.1 Organic fertilizer for dahlias (homemade)

As we mentioned in the previous section, dahlias like soils rich in organic matter. That is why when we transplant it is good to strengthen our soil with a compound that provides the organic matter that these plants need.

It is at this time that we can make use of some of the most famous organic fertilizers, which are also easy to produce at home. Among the best options is the application of compost, well-fermented manure or worms. Add any of them and mix them evenly into the soil before transplanting.

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

3.2 Best fertilizer for dahlia flowers (low nitrogen)

Unlike the Aztecs, we grow our dahlias for their flowers. So if there is any way to improve its flowering we will apply it. One of the precautions to have a more abundant and better flowering is to apply the right fertilizer.

A good fertilizer to stimulate the flowering of your dahlias is especially one that contains a low nitrogen content. This is because nitrogen is responsible for stimulating the growth of stems and leaves, thus neglecting flowering.

Therefore, what we are looking for is a fertilizer rich in phosphorus, the main nutrient that stimulates flowering. In addition, it is also good that it has a good amount of potassium, since it makes the plant less vulnerable to the attack of diseases. A 5-10-10 or 10-20-20 composition may be suitable for your dahlias. Since we have already studied what the NPK values ​​are, you will have noticed that in both mixtures the proportion of nitrogen is low.

Start fertilizing with these low nitrogen fertilizers a few weeks before flowering starts. Then, depending on the type of fertilizer you buy, the regularity of the application can vary. If you buy a slow release, two fertilizations in season may be sufficient, while a quick release will have to do more applications.

3.3 Fish fertilizer

The use of fish-based fertilizers is quite widespread in the cultivation of dahlias. The most common is fish emulsion, which is used many times as a foliar fertilizer.

In general, this fertilizer contains a good proportion of nitrogen, so there are some moments in which it is better not to apply it. As we have just seen, it is not good for it to be used just before or during flowering. And also in other moments that we will analyze in the next section.

3.4 Fertilizer for dahlia bulbs

Before you think about fertilizing your dahlias bulbs make sure you plant them at the right time. Wait for the soil to reach a temperature of at least 60 ° F, something that usually happens in the first days of spring. Or if you want to speed up the process, plant it in a pot and keep it indoors.

Once the soil is at a good temperature, you must make sure that it has a good amount of organic matter. As we said before, this can be achieved with some organic fertilizer such as compost, although you can also replace it with a balanced mix (eg: 5-5-5).

In any case, do not exceed the amount of fertilizer, especially nitrogen. This can end up burning your bulbs. For this reason, many gardeners avoid applying fish emulsion at this time.

4. Feeding dahlias plants


Now let’s summarize what you can clean from the previous section with some quick tips to help you feed your dahlias:

  • They like soils rich in organic matter, so when planting the bulbs you can apply compost or well-fermented manure. You can also use a balanced 5-5-5 fertilizer.
  • If you opt for a liquid fertilizer like 5-5-5, apply it from the beginning until a few weeks before flowering. At that time, stop applying it and replace it with a low nitrogen fertilizer (eg 5-10-10). This will stimulate flowering.
  • If you like to use fish emulsion you can apply it, but try not to do it just before and in the flowering period. It is not the right fertilizer to stimulate the flowering of dahlias.

In general there are not many more secrets to make a correct use of the fertilizer for dahlias. But hey, every gardener has his tricks and you can find one that contradicts everything seen in this post. Sometimes it all comes from trial and error. Since it is subject to many factors such as soil type, climate, rain cycle, etc.

5. Feeding Dahlias with Tomato Feed


A popular method of fertilizing dahlias is to use tomato food, which can provide essential nutrients to promote healthy growth and abundant blooms. Tomato food, commonly available at garden centers, is a liquid fertilizer formulated specifically for tomato plants. While it is primarily intended for tomatoes, it can also be beneficial for other flowering plants, including dahlias.

Tomato foods generally contain a balanced mix of nutrients, including Nitrogen (N), Phosphorus (P), and Potassium (K), along with trace elements that are essential for plant growth. These nutrients play a vital role in supporting various aspects of dahlia development, such as strong stems, lush foliage, and vibrant flowers.

When using tomato food for dahlias, it is important to follow the manufacturer’s instructions for dilution and application. In general, it is recommended to mix tomato food with water in the suggested ratio and apply it to dahlia plants during the growing season.

Start applying tomato food to your dahlias when they start to grow and continue feeding them every two to three weeks until late summer or early fall. This regular feeding schedule ensures a constant supply of nutrients to support continued growth and flowering.

When applying tomato food, be sure to saturate the soil around the base of the plants, avoiding direct contact with the foliage. This helps prevent the risk of leaf burn or other potential problems that can arise from direct contact with the concentrated fertilizer.

Feeding dahlias tomato can provide a convenient and effective way to nourish these beautiful flowers. However, it is worth noting that tomato food alone may not meet all of the nutritional requirements of dahlias. Supplementing with organic matter, such as well-rotted compost or aged manure, can further improve soil fertility and provide a fuller range of nutrients.

6. Fertilizing dahlias video


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

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

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