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3 Options for feeding your orchids (pot plants) using Dyna Gro

Below I describe 3 techniques for feeding orchids and other flowering plants grown in pots (hoya). The techniques can be adapted for use with all pot plants.

We are often asked "How, should I feed my orchid?" or "How often should I feed my orchid". I will address both these questions and provide a few tips on how to improve orchid growth and health.
 
I refer to a nutrient solution and not a fertiliser. Typically, a fertiliser refers to a product designed for use in the garden or soil and only contains a handful of nutrients, not the 17 nutrients found in the combinations of Dyna-Gro products. In terms of orchid nutrition, fertilisers are incomplete and are not the best option for you to use because they of the essential nutrients.
 

Are you starving your pot plants?

Plants are no different from humans. Just as you need a balanced diet to keep yourself healthy and well, so do your plants. Buying any old fertiliser from your local garden supply store may be one of the factors contributing to why some of your orchids may not be growing or flowering that well, i.e. your orchid may not be receiving enough nutrients and are 'starving'.
 

What are essential elements (nutrients)?

Scientists have determined that for all plants to grow, reproduce and keep healthy, they need a minimum of 20 elements. Three of these, carbon, hydrogen and oxygen, are supplied from air and water. The remaining 17 elements are supplied via a nutrient solution. Some deem silicon to be beneficial rather than essential.
 

For an element to be regarded as essential, three criteria are required:

  • A plant cannot complete its life cycle without the element.
  • No other element can perform the function of another element.
  • The element is directly involved in plant nutrition.

Count the nutrients listed on the fertiliser bottle

Check the fertiliser you are using and count how many nutrients are listed on the label. If it contains less than 16 nutrients you will be starving your pot plants and affecting its health and growth.
 

A note about potting substrates (mix)

Most potting substrates used for growing orchids have little or no nutritional value and should not be relied upon as the only source of nutrition for your orchids. The substrate primarily exists to allow the roots to anchor the plant, allow for gas exchange, and provide a domain for water and some nutrients to be "stored" for the roots to absorb. You have to introduce nutrients to the orchid via a nutrient solution. When you pour the nutrients solution liberally through potting mix, orchid roots can come into contact with the nutrients in the solution and absorb them.
 
Nutrients exist in the solution as positively or negatively charged ions. When they come into contact with the orchid root, they are stored by the velamen cells and released to the root (stele) for transportation to various parts of the orchid.
 
Velamen is the white outer covering of dead cells found on orchid roots and they act like a sponge to absorb and store nutrients.
 
Cross section of an orchid root showing the velamen cells.
 
Please note: If you use organic amendments like fish emulsion, seaweed extract or blood and bone, they have to be broken down by the potting mix's biology to convert into a form that orchid roots can absorb. Roots can't absorb bits of fish and seaweed, etc.
 

Copy how orchids get their nutrients in their nature

In nature, when it rains, water falling through the tree canopy or the forest floor picks up nutrients. As the water washes over the orchid roots, the nutrients in the water are absorbed by the velamen cells.
 
Two things I want to bring to your attention are:
  1. Every time it rains, the orchid's roots have access to nutrients dissolved in the rainwater.
  2. The nutrients dissolved in the rainwater exist in very dilute or minor quantities.

This means that orchids are fed fairly regularly with a weak nutrient solution every time it rains. This is why we say that you should feed orchids weakly, weekly, i.e. feed your orchids a weak nutrient solution often.

Orchids are not gross feeders, and a nutrient solution that is too concentrated is detrimental to your orchid.
 
There are several methods orchid growers can choose to feed their orchids.
 

CHOOSING A NUTRIENT PROGRAM

For the programs mentioned below, I recommend that you include the following with your nutrient solution.
 
To every batch of nutrient solution ad the following products:
  • Dyna Gro Pro-TeKt. Pro-TeKt is added as a source of silicon which helps to develop a strong (tough) cell structure and balances the pH effect of the nutrient solution.
  • Dyna Gro Mag-Pro. The additional magnesium and sulphur helps to improve the leaf colour and increase flower count and size.
Once a month, add any 1 of the orchid growth booster products to your nutrient solution:
  • KLN Rooting Solution will gently stimulate the development of roots.
  • Seaweed Soil Concentrate or BioPower Seaweed Flake adds extra nutrients and organic compounds missing from synthetic nutrient solutions.

OPTION I. Use one nutrient solution (fertiliser) all year round.

For this program, you can use one product which has a good balance of nutrients to support leaf growth and flower production.
 
Products that are suitable for this are:
  • Dyna-Gro Orchid-Pro 7-8-6
  • Dyna-Gro GROW 7-9-5


 

OPTION II. Using a nutrient solution to match the orchid's growing phase.

For this program, you use two nutrient solutions, one for the growth phase and another for the blooming phase.
 

I. Growth Phase (Vegetative Phase)

  • The growth phase is when orchids produce new stems, leaves or roots. The nutrient requirements call for large amounts of Nitrogen (N) which the orchid uses to produce chlorophyll and is also a vital component of proteins, hormones, vitamins and enzymes.
  • It is during this stage that most of an orchid's growth occurs.
  • Stimulating growth (leaf production) increases the total leaf surface area. This translates to a plant having more leaf surface area to photosynthesise. It is the by-product of photosynthesis that plants use to create structure(cells). This, in turn, should contribute to better flowers.
 

II. Blooming Phase (Reproductive Phase)

  • This is when an orchid's energies are directed at reproduction, i.e. flower production.
  • During the blooming phase, Nitrogen is no longer the main nutrient required, and fertilisers typically have higher Phosphorus and Potassium levels.
  • Phosphorus is essential for seed germination, photosynthesis, protein formation, overall growth and metabolism, flower and fruit formation, and Potassium is essential for the formation of sugars, carbohydrates, proteins, and cell division. Phosphorus also adjusts water balance; improves stem rigidity and cold hardiness; enhances flowers' colour and oil content.
 

III. Dormant Phase

Some orchids have a period when they require little or no water and nutrients. During this phase, follow the recommended cultural guidelines for the orchid.
 
Use a nutrient solution to match the growing phase. Orchids and most plants have two phases, a growth phase and a blooming phase.
 

Using Dyna Gro Nutrient Solutions:

  • Growth Phase - Dyna-Gro GROW 7-9-5.
  • Bloom Phase - Dyna-Gro BLOOM 3-12-6.
Choose a fertiliser program that matches an orchids growth phase

 

OPTION III - Nitrogen Cycling, match Nitrogen levels to daylight length

The Nitrogen Cycling program was shared with me by Malcolm Moodie a member of the British Paphiopedilum Society. He is also an award-winning paphiopedilum grower.

The image on the left is one of his plants grown using the Nitrogen Cycling program

Paphiopedilum Fumi's Delight

(P. armeniacum X P. micranthum)

Certificate of Cultural Commendation by the RHS Orchid Committee in March 2022

Paphiopedilum Fumi's Delight grown by Malcolm Moodie, RHS Certificate of Cultural Commendation

As the earth moves through the four seasons, daylight length changes. The image below shows the difference in daylight hours for New Zealand. The longest daylight hours occur from December to January, and the shortest daylight hours occur from June to July.

Matching nitrogen levels to New Zealand daylight length

When the daylight hours are the longest, plants will be photosynthesising more than during shorter daylight hours.

Chlorophyll is the compound plants use to convert energy from the sun to produce sugars from water and carbon dioxide. Plants use these sugars (carbohydrates) to produce plant structure (growth). Nitrogen is a major part of the chlorophyll molecule.

We can conclude that during the longer daylight hours, we should be applying more Nitrogen and less Nitrogen for the shorter daylight hours.

Dyna Gro products to match New Zealand Daylight length
We can use three Dyna Gro nutrient solutions to achieve this program:
  • Dyna-Gro Foliage Pro 9-3-6 contains 9% Nitrogen. It is used when higher levels of Nitrogen are required.
  • Dyna Gro GROW 7-9-5 contains 7% Nitrogen. It is used when transitioning from a high Nitrogen nutrient solution to a low Nitrogen level nutrient solution.
  • Dyna Gro Bloom 3-12-6 contains 3% Nitrogen. It is used when the lowest level of Nitrogen is required.

We feel it is very beneficial to include Mag-Pro and Pro-TeKt with every feed for all programs, regardless of the season. 
 
  • Plants require Silicon (Pro-TeKt) for strong cell structures and rebalancing the pH effect of nutrient solution.
  • Increased Magnesium improves the leaf colour and increases flower count, size and bouquet.
  • We also recommend boosting plant growth and health from the addition of KLN Rooting Solution or Seaweed once a month

PS: The fertiliser, Pro-TeKt and Mag-Pro should be mixed together in the water. Always add the Pro-TeKt first then the rest of the ingredients. The same applies to the monthly application of KLN or Seaweed.


MORE OPTIONS

Dyna Gro Pro TeKt strengthens cell walls

Option 1. Strengthen cell structure, improve pest and disease resistance, heat, cold and drought stress and assist with nutrient uptake.

Dyna Gro Pro-TeKt is a supplement that supplies silicon and higher levels of Potassium to build stronger plant cell walls. Pro-TeKt is a replacement for the silica normally found in soils and generally is not present in potting media.
 
Some of the benefits for including silicon with your Dyna-Gro Nutrient Solution are:
  • Assists with nutrient uptake, increase the rate of growth and develop stronger stems.
  • Helps support the weight of dense flowers.
  • Deposited in a hard, opalene form in the epidermis of leaves and stems which adds mechanical strength and supports a plant's natural defence against insects and fungal infection.
  • Helps plants become more tolerant to drought, heat and cold stress.

 

Option 2. Support flower development and photosynthesis by feeding additional Magnesium, Sulphur and Phosphorus

Dyna-Gro Mag-Pro encourages the development of flowers and will assist improve the beauty of their orchid flowers.

  • This unique plant supplement can be used with any Dyna-Gro Nutrient Solution as a blossom booster to help initiate flowering and develop large, vibrant, fragrant flowers.
  • Mag-Pro gives your orchids the ability to access the nutrients they need at critical times of flower formation to ensure massive growth and aroma through increased production of essential oils, terpenes, and flavonoids.
  • Use Mag-Pro instead of a calcium/magnesium supplement because there is ample calcium in all Dyna-Gro Nutrient Solution formulas.

 

Option 3. Increase Root Growth and Mass with KLN Rooting Concentrate

K-L-N Concentrate is a blend of nutrients known to help stimulate the production of vigorous root development in all plants.

  • One of your objectives for growing orchids should be to cultivate a good, healthy root mass. It stands to reason that a healthy, vigorously growing root mass, forms a good foundation for growth and flowering. Roots are the main vehicle plants use to absorb water and nutrients.
  • One way to maintain and stimulate root growth is to use K-L-N once a month. Incorporate it with the Dyna-Gro Nutrition Solution of your choice. 
  • Use K-L-N Concentrate added to your Dyna-Gro Nutrient Solution once a month throughout the growing season. Do not use K-L-N Concentrate during periods of dormancy, or when flower initiation is desired.

 

Ocean Organics Soil Concentrate used for feeding orchids

Option 4. Improve growth and plant health with a seaweed drench.

  • A monthly root drench with Ocean Organics Soil Seaweed Concentrate supplies the nutrients that are missing from nutrient solutions plus a whole lot of the compounds that help to promote growth and health.
  • It is not uncommon to hear plant fanatics mention how seaweed has changed the well-being of their plants.
  • Please note that seaweed is not a fertiliser it does not contain enough NPK to continuously support plant growth. It should be viewed as a tonic for plants, similar to the concept.

 

Optimising the pH of your nutrient solution for better absorption

pH is a logarithmic scale used to measure the acidity/alkalinity of your nutrient solution. The scale ranges from 0 to 14. If the pH is 7, the solution is considered to be neutral. A pH value less than 7 is considered acid, and a pH value greater than 7 is alkaline.

The pH of your nutrient solution is important because it affects the availability and absorption of all the mineral elements needed for plants to grow. The best absorption of these elements is at pH readings of between 5.5 to 6.8.  

When pH falls outside this range, many of the elements will be less available, and the absorption of the micronutrients can reach toxic levels.  

Dyna Gro have a chart that illustrates nutrient uptake and availability based on the pH range.

Products that you can use to modify the pH range of your nutrient solution are:

  • Dyna Gro pH Down
  • Dyna Gro pH Up
  • Dyna Gro Pro-TeKt

I have also written a short article on how to use citric acid to adjust the solution pH.

CONCLUSION

  • Fine-tuning your orchid nutrient program is not the only step of your orchid growing journey. Other factors like the light, humidity, temperature range, type of potting mix and watering frequency also need to be optimised.
  • Remember the above recommendations are not absolute, they are a recommendation. Experiment with dosage rates to find what works with how you grow your orchids. Compared to other plants, orchids grow slowly. It may take some time to see the results.
  • Of the options mentioned above, I believe that the nitrogen cycling program is the best option.
  • Dyna-Gro has been developing and providing growers with products and information for over 34 years. Their products work and produce excellent results for growers all around the world.
 

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