Basic Fertilization Questions

[Ray]

Originally Posted by HiOrcDen

How do you apply fertilizer when watering with a hose? Do you use the hose attachment that holds and dispenses fertilizer automatically as you water, along with the rain head you mentioned? (maybe both features in one attachment?)

There are many ways to "skin that cat". When I grew in a greenhouse, I used a metering pump the injected a liquid fertilizer concentrate into the water passing through the hose. I used a Dramm Water Breaker to make it "rain".

Now that I have retired and downsized, and have no greenhouse, when the plants are out on my deck, I use an Ortho Dial-and-Spray hose-end sprayer to add the fertilizer and other additives.

When they are indoors over the winter I use a battery-powered backpack sprayer that also has a wheeled dolly so I can just roll it around. I put everything in that and adjust it for a coarse spray.

and if so what concentration do you place in the attachment? (If it's not too much trouble could you tell me the name of the attachment you use?)

How do you water very small plants, like in 2-3" pots, just shower over them? Also, when you say tiny amounts of fertilizer, is that the 25-50ppm that Estación Seca described?

Again, it varies with the circumstances.

When the fertilizer was injected with the metering pump in the greenhouse, I used 25 ppm N and watered 3-4 times a week. In summer outdoors, here in NC, I have to water frequently, but being more of a hassle to use the hose-end sprayer, I feed weekly at 100 ppm N.

I generally recommend that you think about the frequency of feeding, then sum up the concentrations applied, making the total somewhere in between 75 and 125 ppm N.

Under my "equal abuse" policy, all plants are treated the same.

[Arizona Jeanie]

It seems like slow release fertilizer would just wash out of an open bark medium long before it had a chance to release its nutrients.
I'm not sure what a "strong organic mix" would be, but you don't want to add anything that would clog up the air spaces in your potting medium.
The Miracle Grow Orchid food (and there are others) is formulated to meet the needs of the plants. I'd use the 1/4 tsp per gallon, weekly. I doubt you'll see any signs of deficiencies in your plants, but if you do you can adjust accordingly at that time.
Thanks ES and Ray for the more detailed explanations, but just following instructions on the orchid food container has actually worked pretty well for me!

[estación seca]

I would water thoroughly each time. Just wetting the surface means dissolved minerals dry on the upper part of the medium.
This shows as powdery white efflorescence, which may damage roots.

[Roberta]

Thorough running-out-of-the-pot watering has the additional benefit of pulling fresh air into the root zone, along with flushing out any buildup of fertilizer salts and other crud,

[WaterWitchin]

"Equal abuse policy." That's the policy I follow here as well. Well-stated.

[Roberta]

For a small collection, a 2 gallon pump sprayer is handy. You can fill with your fertilizer solution (or plain wanter) and easily carry it around. that is my "indoor hose" and also how I used to fertilize outside (long after my collection could be considered "small".)

[Orchid Whisperer]

Any water-soluble fertilizer that provides N, P, and K is fine. If it also provides Ca, Mg, and trace elements, even better (if your water supply does not have much of these). More frequent but dilute applications seems better than infrequent strong applications.

An orchid does not really care whether nitrate-N, ammonia-N, K, or P comes from an organic fertilizer, or a fertilizer that might be considered "inorganic". Also, most orchids don't need much fertilizer, as others have said. Wild orchids living in trees get their nutrients from animal wastes, plant exudates, plant and animal debris trapped in the orchid's roots, really anything that comes along. Some of the nitrogen actually comes from rainfall itself.

Slow-release can be OK, and I know people that have used it. The fertilizer is in small spherical capsules called"prills". If you go this route, shop carefully for types meant to be very slow release, for epiphytes. A friend that used slow release has cautioned that some cheaper slow release fertilizers can "dump" their remaining fertilizer all at once under certain conditions (not desirable). I don't recall the conditions that causes that dumping, but frankly, it was a reason I have stayed away from slow-release fertilizers for orchids.

[Roberta]

I use slow-release ferilizer in addition to my regular regimen for particularly rapid-growing, "hungry" types... mostly Cymbidiums and Catasetinae, in the spring. Contrary to usual perception, they don't leach their payload so much in response to water as response to temperature. So a hot spell can produce a burst. Which is OK for those fast-growing types, they are likely to also increase their growth in hot weather. But it's likely to be too much for most orchids. In general, it's better to under-fertilize than over-fertilize. Too little and the plant may not grow to its full potential. Too much and you can burn leaves and roots, damage the plant.

[WaterWitchin]

I use just as Roberta says… plants like Cymbs, Ctsm, that can just drink it down with the rapid growth cycle. For most… weak and infrequently.

[Roberta]

I found that a 2 gal pump sprayer was completely adequate for quite a few orchids... before I bought my house, when I first got into orchids, I lived in a condo and the spare bedroom became my "greenhouse" http://orchidcentral.org/GrowingAreas/indoor.jpg .
I just watered these until the water ran out of the pot. The bins under the plants caught the water. its evaporatuin raised the humidity a bit. I only had to clean out the bins every 6 months or so when the algae got too ugly.