Cacti usually accompany their owners for many years. Here you can find out what you should consider when using fertilizer for cactus.
If you don’t have a green thumb, you will at least get a cactus (Cactaceae) to make ends meet – at least that’s what they say. In practice, however, one often hears the phrase “Even the cacti die on me”. Fortunately, it is not that difficult to take care of frugal beings. And with a little knowledge you can achieve a lot.
Cacti grow slowly. It’s no wonder, because the hardy plants come from the barren regions of America. In order to better understand cacti and their needs, you should dare to take a look at the world of their prickly contemporaries: It is mostly dry here and the rare availability of water determines the rhythm of life. The surrounding vegetation is sparse and there are few dead plant parts that could be converted into humus. The earth therefore mainly consists of mineral components. To make ends meet, the cactus has to slowly and steadily build up biomass.
With these conditions in mind, you basically have everything you need to know to keep your cactus happy.
When to Fertilize Cactus
In their homeland it rarely rains, but it rains heavily. Only then can the cacti absorb nutrients with the water. The fertilization is therefore heavily dependent on the watering and should also be done via the irrigation water. The liquid fertilizer Cactus Plus 2-7-7 from Schultz is ideal for this. During the growing season, fertilize every one to four weeks, depending on the type of cactus.
In winter, like most plants, cacti require a rest period. That is why the last fertilization of the year is in August. The first dose is only given in April or May, after the cactus has started the growing season. The main fertilization season is in June and July. In these two months you should give your cacti more fertilizer than in May and August.
Recognize deficiency symptoms in cacti
Cacti generally get by with few nutrients. It is therefore usually better to fertilize too little than too much. Too much can quickly lead to soft tissue.
Symptoms of deficiency appear late and do not emerge as quickly. So try to find the right amount of fertilizer. If the cactus begins to lighten, this is a clear sign of a lack of potassium or nitrogen. The lightening is usually strongest at the base of the cactus and sooner or later it becomes woody. The deficiency is also accompanied by a slowdown in growth.
The cactus can also lack phosphorus. However, this deficit manifests itself rather subtly in the absence of blooms, because phosphorus is particularly important for the development of flowers and fruits.
The Best Cactus Fertilizer
Over 100 species of cacti are known worldwide. It is therefore logical that not all cacti have the same requirements. The family is diverse. Still, there are fundamental similarities in terms of nutritional requirements.
Nitrogen is absolutely vital for cacti. It promotes growth, but in too large quantities it also leads to soft tissue and a higher susceptibility to disease. So the best cactus fertilizer contains nitrogen, albeit in moderation.
Potassium is essential for stability, so it is also of great importance for cacti. It also plays an important role in storing water in the cells. A good fertilizer should therefore contain sufficient potassium, ideally even more than nitrogen. Phosphorus is also more important than nitrogen in fertilization. This nutrient is particularly important for the formation of flowers and fruits.
In addition to various essential trace nutrients, the best cactus fertilizer also contains nitrogen, phosphorus and potassium. The main difference to conventional fertilizers lies in the ratio. While fertilizers usually contain significantly more nitrogen than phosphorus and potassium, the reverse is true for cactus fertilizers. If there is as much or even less nitrogen than phosphorus or potassium in the fertilizer, this is a good cactus fertilizer ratio.
Last but not least, you should of course not ignore the pH value. Cacti need a pH value between 6 and 7. Only then do they feel really good and can thrive. If, on the other hand, the value is too acidic or too basic, some nutrients are less available to the plant.
Organic Fertilizer for Cactus: The Right Approach
Those who like to fertilize their plants organically will be more likely to be disappointed with cacti. In the area of origin of the robust plants only little flourishes and so there are few plant parts from which humus could be formed. In addition, animals can hardly find anything to eat here, which is why there is little manure. Therefore, cacti mainly draw their nutrients from the mineral components of the soil.
For organic fertilization, a liquid fertilizer such as Cactus Plus 2-7-7 from Schultz is recommended. Mixed into the irrigation water, the valuable nutrients can easily be added to the previously moistened cactus substrate. One advantage of cacti is that there is no risk of leaching through infrequent watering.
Mineral Fertilizers for Cactus
Any fertilizer with the right nutrient ratio is suitable as a mineral fertilizer. Cactus fertilizer naturally fulfills this requirement, but is often more expensive than other fertilizers. Mineral salts can also be dissolved in the irrigation water and used as fertilizer. However, moisten the substrate beforehand before using fertilizer-enriched irrigation water.
Home Remedies as Cactus Fertilizer
In fact, there is an organic home remedy that is great for cacti: coffee grounds. This is generally not very rich in nutrients, which makes over-fertilization difficult. It also contains mainly phosphorus and potassium and only in third place nitrogen, which perfectly meets the needs of cacti. As a bonus, coffee grounds are acidic and thus counteract an excessively high pH value. This home remedy can save the day, especially with calcareous irrigation water.
How to Make the Best Fertilizer for Cactus
Since cacti are more used to a mineral environment, making the fertilizer yourself is not that easy. To do this, you would have to acquire the individual nutrients – i.e. nitrogen, phosphorus and potassium – as well as the micronutrients such as copper and zinc and mix them together in the correct ratio. Apart from the fact that the mixing together requires special conditions, you unfortunately cannot save any money, because the individual nutrients are expensive in household quantities.
Even if cacti are generally the easiest plants to care for, there are still a few little things to consider. To learn how to maintain your cacti correctly, please refer to our articles on the care of cactus indoors and outdoors.