Feeding Orchids

When you are cultivating orchids, focus on nutrition is of utmost importance. In other words, nutrition of orchids is highly essential. Although the medium used to cultivate orchids may contain a number of elements that are essential for the growth of orchids, they do not contribute much to the plant's health till the medium begins to break down. Unfortunately, when the medium just starts breaking down, most orchid growers generally abandon it and repot the plant. Sometimes, orchid growers incorporate specific nutrients in the growing medium while preparing it. However, many of these nutrients do not dissolve just after the first watering. In such cases, the potency of the solution may damage the roots and wash them out quickly. In present times, growers usually put the nutrients in the medium in a soluble form and they are made highly diluted by supplying plenty of water. If possible, this ought to be done every time you water the plants. The key to growing orchids successfully is applying the nutrients in small amounts, but very often.


The NPK rating of a perfect fertilizer mixture may be something like 20-20-20. In effect, these numbers represent the percentage of the three main elements - Nitrogen (N), various phosphorus oxides (P) and potassium (K) present in the fertilizer.

A growing orchid mostly requires nitrogen and a fertilizer having a NPK rating of 20-20-20. Any fertilizer having this NPK rating is considered to be an excellent all-round one. An orchid requires maximum amount of nitrogen when it is growing robustly and under intense light. On the other hand, the plant require minimum amount of nitrogen during its dormant stage or when it is growing under low light conditions. If you find that your plant is facing problems in flowering, it is advisable that you lower its nitrogen intake. It has been found that this often helps plants to bloom.

In addition to nitrogen and a fertilizer having a 20-20-20 NPK rating, plants require calcium, sulfur and magnesium for their growth. Although the plants require some additional minerals, they should be provided in very small amounts and are, hence, known as trace elements. These trace minerals include copper, boron, zinc, molybdenum and manganese. Good commercially available soluble fertilizers for orchids should essentially contain the above mentioned minerals and in appropriate proportions. It is advisable that you refrain from adding these minerals by yourself because excessive amounts of these minerals may often prove to be toxic for the orchids. Despite this, if you want to add them to the medium yourself, be very cautious while blending the minerals.


Generally plants do not suffer from deficiency of calcium, but this problem is sometimes found in orchids. If you add lime in the growing medium at the very beginning, it is unlikely that the plants will suffer from calcium deficiency. In fact, the water supplied by municipalities may contain calcium, especially hard water. We are especially discussing the issue of calcium in this article because the preparations available on the market rarely have any calcium. The main reason for this is calcium leads to precipitations (solid deposits) when it is incorporated into any concentrated liquid solutions. In addition, it causes caking as well as other problems when used in dry mixes.

Calcium is considered to be a non-mobile element. In other words, a plant is unable to move this element from its older parts to new growths in case there is a deficiency of this mineral. This is the main reason why growers should always have a ready stock of calcium at their disposal. If you can get calcium nitrate, you can add the compound to the medium in proportions of roughly 0.02 ounce for every gallon or 150 mg for every litre. In case calcium is dissolved independently and then incorporated into the watered down feed solution it is unlikely to have any precipitation.


Urea is the most inexpensive form of nitrogen and perhaps this is the reason why it is frequently added to several soluble fertilizers that are currently available in the market. However, it is important to note that the roots are unable to absorb urea. When added to the soil, urea breaks down into simpler compounds that are easier for the roots to take up. Since orchids are grown in a sterile media, it is likely that urea will break down in a manner that it releases nitrites and ammonia. However, neither of these two is beneficial for the health of the roots. Urea is excellent for foliar feeding. The leaves can take up urea somewhat easily and safely. In addition, foliar feeding of urea may also help making passage for other elements to enter the leaf easily. Usually orchids respond well to foliar feeding. Nevertheless, it is important to keep the preparations highly diluted and ensure that they are not near the roots.

Fertilizer strength

People using fertilizers for their plants should be very clear about one thing - the NPK ratio of a fertilizer and the strength of a fertilizer are two different things. The NPK ratio of a fertilizer actually does not offer any information regarding how much of it you should use. In fact, the quantity of each element, such as nitrogen, phosphorous oxide and potassium, may be stated in parts per million. Findings of various experiments have suggested that using 100 ppm of nitrogen (N) is just the most favourable for majority of the epiphytic orchids, while feeding 150 ppm or additional is appropriate for heavy feeders like cymbidiums. If you dissolve roughly 0.07 ounce of any fertilizer with 20-20-20 NPK ratio in one gallon of water, it will have 100 ppm nitrogen, 44 ppm of phosphorus oxides and 83 ppm of potassium. According to a rough estimate, one level teaspoon of NPK 20-20-20 fertilizer will be around 0.14 ounce or 4 grams. However, this will not be the same if you use a heaped teaspoon of the fertilizer.

You should not increase the potency of the feed too much whenever you water the plant. In fact, it will do more harm to your plant than good if you increase the amount of fertilizer by 10 times during every tenth watering. In case you are using any patented liquid fertilizer brand, things will be somewhat more difficult if you are not aware about its concentration. On the other hand, if you are using a product that has been manufactured by any reputed company especially for orchids, it will be safer if you follow the instructions on the product label. In case you have any doubts, you should preferably use the feed in 50 percent of the recommended strength or perhaps even less.

These days, you can purchase various slow-release fertilizers. In fact, slow-release fertilizers containing organic salts that have some sort of coating and are released gradually over a period of time are very popular among people growing orchids. While these fertilizers do help to save a lot of time and effort, the downside of using them is that you actually have little or no control over their pace of release or will not come to know when the material is completely used up. Hence, it is advisable that slow-release fertilizers should always be used sparingly and they should always be place on the surface of the medium you use for growing your orchids.

Organic versus inorganic fertilizer

Organic and inorganic (synthetic) fertilizers differ in a number of ways. The main difference between the two is that the organic fertilizers are very complex by nature and they can only be used by plants after they have been broken down through bacterial processes. In addition, compared to inorganic fertilizers, the nutrients in organic fertilizers are released very slowly. Fish emulsions, which are basically a liquefied by-product of fish, have an NPK ratio of 5-1-1.

Compared to organic substances, plants usually avail inorganic sources almost instantly and much of it is also not lost due to leaching. Nutrients obtained from any inorganic fertilizer usually become conspicuous in the system of a plant within an hour or maybe even less.

Several studies have been undertaken on this subject and their findings regularly associate considerably less population of pests when people use organic fertilizers. On the other hand, the pest population has been found to be greater when growers provide the plants with very soluble inorganic fertilizers. In addition, use of organic fertilizers helps plants to remain healthier as well as more equipped to endure stress. Usually, organic fertilizers are expensive and they promote faster break down of organic potting mixes as they have augmented microbial activities, which is essential to break down any fertilizer into simpler compounds. In fact, organic fertilizers have a tendency to wash away very quickly from potting mixes meant for epiphytic orchids.

You can make an effective organic fertilizer at home by permeating very old cow mature in water and subsequently employing the resultant watered down "tea" as a fertilizer for your orchids. The method involved in preparing this home-brewed fertilizer is quite simple. Add 20 tablespoonful of the aged cow manure having a NPK ratio of 4-4-2 to one gallon of water, shake the matter and subsequently leave it for 24 hours to settle. Then you need to decant the resultant tea from the deposit at the bottom to a bucket with a 5-gallon capacity. Add enough water into the bucket to dilute the tea. You should water down the mixture further and when using it should have a 1:16 ratio. It is worth mentioning here that teas cannot be considered to be robust fertilizers. At the best, they are a good general tonic for your plant.


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