Fertilizer...Do they really need it?

[Aleksa]

In every culture sheet I have red writes that epiphytic orchids should be fertilized regularly with diluted fertilizer... I followed the tips and fertilized them regularly. But later, when my collection grew, I stopped adding fertilizer. I haven't noticed absolutely any change on my plants since that (that was around a year ago)... When you think... How are orchids fertilized in nature? There is no much minerals in bark... From where do they get the food? I know that they produce sugars and other products using photosynthesis, but they virtually have no access to other source of 'food' like minerals and elements... How is that possible? A lot of energy is needed to create so beautiful and large, long lasting flowers... Where do they get it?

Is is there any orchid that requires heavy feeding?

[jerrymeola]

Do humans need food to live and grow?

Orchids need food but need very little. This is why you do not see big differences.

In humans, the failure to feed a child enough food or the wrong types is recognized as a medical condition called 'failure to thrive'. It does not kill the children, but you will find a 10 year old no larger than a 6 year old. Then there are all kinds of related medical problems that will haunt the child for the rest of its life, both mental and physical. 'Failure to thrive' is considered child abuse.

Orchids certainly fail to thrive when not feed. It is not noticeable to you because you do not have standards against which to compare.

We have a couple of growing projects in the forum. In the Hybrid project I am keeping a control set of plants. After only a few months I am seeing big differences in the condition of my control plants and the slower growth of the members.

I posted two pictures of a control plant only two months difference in this post

Update on Epi. Mabel Kanda, Bc. Little Stars and Blc. Haleahi Sunbow

Have any of your plants shown this much growth in the year without food?

If you do not have time use 6 month slow release fertilizer and in seconds a plant is done for six months.

[renata]

Ok, Aleksa, I consider myself as a beginner, but I guess, from what I've read that orchids in nature receive a lot of nutrients when rain carries them down from the tree tops...The roots absorb every nutrient that's coming down with the water and that includes bird poo, rests of smaller animals and other organic materials....Besides that they utilize the high umidity of the air around them....
From what I remember, Vandas do require a lot of feeding, weekly fertilizing sometimes, diluted of course..
Well, let's wait for the rest of the bunch to teach us something more...
See ya!

[digitalgate]

Agreee with Jerry.

[Brooke]

Think of fertilizer as a vitamin because the plant produces it's own food via their leaves and roots.

Jerry couldn't the difference between your control plants and the ones distributed to the members simply be you live in orchid heaven and most of the members live in the frozen tundra and grow them inside? I would be happy to have you send me a plant and grow it in the g/h to see if I can match your growth :>)

Brooke

[Aleksa]

Originally Posted by jerrymeola

Have any of your plants shown this much growth in the year without food?

If you do not have time use 6 month slow release fertilizer and in seconds a plant is done for six months.

Yes, now I completely understand that! They are adapted on those harsh conditions.

Actually, my chids are growing like crazy! New leaves, growths and spikes are everywhere... Indeed, I am surprised. But I also believe that they actually got some fert but not directly. The thing is, I watered them couple of times with water which went through potting mix of my other terrestrial plants, so it contained some minerals also.

Unfortunately, there is no slow-releasing fertiliser to buy, just those liquid ferts.... I'm now exploring that new thing, the worm tea. There is also no worm tea to buy here but my uncle is producing substrate for plants using worms so I'm thinking to try to produce the tea myself. I believe that orchids would like it more than that liquid fert....

[jay]

If you grow any orchids in S/H then you definitely need fertilizer. In an organic (bark, moss) media, there is a small amount of break down that releases a minimal amount of nutrients for the plants. However, in S/H where the media is clay, they can only get the nutrients from the water.

[Aleksa]

Originally Posted by jay

If you grow any orchids in S/H then you definitely need fertilizer. In an organic (bark, moss) media, there is a small amount of break down that releases a minimal amount of nutrients for the plants. However, in S/H where the media is clay, they can only get the nutrients from the water.

Yes, I grow couple of them in sh. They get the fert regularly...

[JLu]

The chemical elements in fertilizer really are not plant food. They are building blocks of the various plant tissues. The plant makes and "eats" sugar. Without fertilizer the plant will suffer an inability to make its vital parts including the chlorophyll used to make sugar from water, carbon dioxide, and light.

There was an interesting theory in Orchid Review regarding the source of epiphytic orchid nutrition. The author postulated that sap exuded from the host tree washed down in rain. The sap would include the needed nutrients. This author actually collected sap beneath a tree during rain and showed that nutrients were present. As a control he collected the same rain water in a clear area to show it did not contain any nutrients.
Personally I've never believed the bird dung theory. It's too random an occurrence to support the plant. I think the sap theory explains why orchids only grow in cewrtain types of trees.

[jerrymeola]

Brooke

Florida is not the heaven you may think.

It has rained every evening this month. For those who worry about watering your orchids at night, mine have been soaked at dark every day and never dry out over night.

The potting medium can be wrong out like a wet towel.

Bacteria and fungal growth are a constant battle. I had mushrooms growing in the pots last week. Now that is wet.

I used to try to fertilize every week and often did not get to it. I switched to slow release fertilizer that is always present and got on a regular bi-weekly spraying of worm tea, Companion and Essentials. The difference was tremendous.

Dendrobium that I am phasing out have not been getting the care and are barely growing. They are larger each year and flower every season, but it takes a lot longer to flower. Properly fed and watered plants grow much faster and my turn around time from small to salable is half.

[renata]

Originally Posted by JLu

The chemical elements in fertilizer really are not plant food. They are building blocks of the various plant tissues. The plant makes and "eats" sugar. Without fertilizer the plant will suffer an inability to make its vital parts including the chlorophyll used to make sugar from water, carbon dioxide, and light.

There was an interesting theory in Orchid Review regarding the source of epiphytic orchid nutrition. The author postulated that sap exuded from the host tree washed down in rain. The sap would include the needed nutrients. This author actually collected sap beneath a tree during rain and showed that nutrients were present. As a control he collected the same rain water in a clear area to show it did not contain any nutrients.
Personally I've never believed the bird dung theory. It's too random an occurrence to support the plant. I think the sap theory explains why orchids only grow in cewrtain types of trees.

J LU,
I found your post very interesting , could you tell me what is "sap"? Tell me a bit more about this theory....
Thanks!!!

[Brooke]

Jerry the difference between your FL growing and growing something inside, in a window or under artificial light is the reason your plants grow better and faster for you. It is the number of growing days permitted by higher light intensity for a much longer period of time.

Will the plants grow and bloom under the conditions in the north - yes but at a much slower rate. Will they grow better in south Florida - yes, because even with your rain, the sun, light and temps are better for many months, not just a couple of months each summer.

Just tell your plants with the fungus and bacteria and mushrooms it is the rainy season just like their natural habitat. Throw them in a non-organic media and welcome the change of not having to water them :>)

Brooke

[made4engineering]

The rainforest canopy is an ecosystem in itself. All sorts of animals live their entire lives in the trees: frogs, lizards, squirrel-like things, a ton of bugs, etc. All of them pooping all over the trees.

[kmarch]

JLu makes some excellent points. And Jerry's point that orchids require few nutrients is also worth highlighting.

I have not systematically fertilized my orchids for maybe 5-6 years. I give my Cymbids a shot in the spring and that's about it. The only "building blocks" (to use JLu's term) available to them is what is present in the potting mix and the city water I use. For this reason I am of the opinion that fertilizing is not required but that depends on one's growing circumstances. For example if you are using a completely inorganic mix, there aren't going to be very many of those building blocks available for the orchid to use.

While I am fully satisfied with the results I get (check out the thread Orchid du Jour to see some of my postings), it does beg the question as to whether my results would be better if I did fertilize. Maybe one of these days I'll get ambitious enough and go back to fertilizing and find out.

[Jerry Delaney]

An interesting discussion. Brooke, I only grew under lights for about 3 years (and hope I never have to do it again) but in some ways, I found it preferable to growing in a greenhouse. I never had a cloudy day, could adjust the light cycle through out the year, could easily control the temperature and humidity etc. But, I had a dedicated area set up in the basement so I did NOT have to contend with trying to balance human comfort with plant comfort. The biggest problem was -- well let's just say that the light and power company has filed for chapter 11 since I left!!!
The comments made about fertilizer are quite interesting. JLu, unless the orchid is growing directly under a bird roosting place or a monkey bedroom, they had better have an additional source. Your sap story makes real sense. For us nontechnical types who just use tap water for most of our watering should make it a habit to check with the water company once in a while to check what we are giving our plants (I get an analysis from our water company each quarter). When I lived in central Illinois, every spring we would have "water alerts". The spring rains would flush lots of nitrates out of the soil (added as fertilizer for the corn & soy bean crops) and since the city water supply was derived from the local river, those nitrates, and God knows what else, wound up in the drinking water. High nitrate levels are dangerous for young children and some immature pets. The "alerts" would be announced on the radio and TV and parents could bring in a birth certificate to the grocery store and get free bottled water for children under three (the stores were then reimbursed by the city). So, it was amazing how much nitrogen you could give your plants by just watering them.

[Aleksa]

That sap theory makes sense to me... But also, we shouldn't forget that in tropical rain forests every tree is small ecosystem like made4engineering said. In so humid conditions moss is always present, bromeliads, tillandsias... Moss can hold water longer and below it, the bark is decaying...

In pots, bark stays wet longer than on trees (that's why we don't have to water plants every day) and it decays much faster creating 'building blocks'... That's why our plants can grow nice without addition of fertiliser...

[JLu]

Made4 and Aleksa, one thing to keep in mind.....while I agree that the rain forest canopy is a complex ecosystem, most neotropical orchids do not grow in the rain forest. The rain forest concept might apply to the Indonesian and Asian rim orchids. I'm not that familiar with the Indian Ocean/SouthPacific regions so I'm not commenting on them. Maybe someone else can do that.

In South America there are few orchids (but some) found in the area us dumb Americans visualize as the equatorial rain forest of the the Amazon region in the state of Amazonas, Brazil. Largely the Brazilian orchids come from the Atlantic coastal and the adjoining inland area that is partially mountainous and partially semi arid rolling plains with large outcroppings of limestone cliffs. This area also is the home of numerous rivers that support strips of larger trees and vegetation, but the key here is that these riverine environments are geographically separate from each other and make up a small part of the overall landscape. True many orchids are found in trees along the rivers, but many grow on limestone outcroppings, in scrub vegetation along the Atlantic coast, and in the mountain areas separating the two. The cloud forest species of Peru, Ecuador, Bolivia, Columbia , and Venezuela do grow in trees, but it would not be correct to view these as rain forest environments where the canopy essentially dominates everything by shading the ground.

So forget the mythical, movie view of canopies teeming with pooping life that support orchids below. When you look at the scrub areas (for instance), orchids tend to favor certain scrub trees..why? You could make a case that birds poop in those trees, but my observation of birds is that they poop whenever the urge comes not over certain tree species. There is something special about those trees that allowed the evolution of orchids and that something had to be more consistent than a crow with a poop urge.

I'm not defending Geoff Hands theory in Orchid Review. I'm just saying it makes some common sense. Both the author and Orchid Review are British. I have no special knowledge of Geoff Hands. The article describes him as a grower with over 45 years experience and current grower of over 2000 orchids. Additionally, his biography suggests he is respected in British orchid circles. He says (spelling is his),"I was dissatisfied with explanations claiming that orchid roots trap leaf mould particles, or that bird droppings provide fertiliser". He made some rain water collections in Thailand to help prove his theory that tree sap is exuded from stomata and when it rains this sap (containing sugar and plant nutrient elements) is washed down. It was an amateurish effort with minimal analytical chemistry support, but seemed to substantiate his theory as far as it went.

Hopefully someone with the financial backing and research skills required will pick up this work because I do not think we know how orchids get their fertilizer. I'll be happy to go to Brazil and do it if you all will bankroll me. I spent a month there and loved the country and people and most of all the Amazon. Two of the weeks were spent in Manaus. Since third grade geography I've loved the Amazon. Believe me folks it makes the Mississippi River look like a creek.

renata, if you PM me your e-mail address I will try to scan the article and send it to you.
Why don't you describe the areas of Bahia, Minas Gerais, Rio de Janeiro, and Espirito Santo for us.

[Hummer344]

WOW, what a discussion. In simple, & short, terms. My orchids show more growth with fert than without. I was wondering what kind of extended release fert. people use. Most of the long term ferts that I know of must be dibbled into the soil in order to break down properly. The potting medium for orchids is loose, not compact, thus the fert. would stay dry, for the most part, and not break down.

[JLu]

I agree with you Hummer. The slow release products that I know about have a lot of urea which is useless in orchid pots.

[jerrymeola]

The slow release fertilizer we use in Florida is Floritan. It is sold retail as Dynamite. It is a water release fertilizer so as water runs over the pellets the fertilizer is release in very small amounts. It is most common as 13-13-13 but it is also made 17-4-9.

I do not like osmocote since that it temperature release over 75 degrees.

Brooke your point about the longer growing season is accurate, but whenever I give an example I always use a time frame that anyone can match. All the examples I have given are from the hybrid project - April to current. I can grow into November and again starting in February, but I do not give those growth periods as examples.

It may surprise you that growth during this extended period is minor. The genetics of the plant slows growth. I get extra growth but not as much as you might think.

The thread I cited was for growth from May to current. Everyone should have good growth during that time.