If you're flushing the soil each time you water, you should be able to use 1/4 tsp 9-3-6 per gallon at every watering - unless you would consider your light levels to be quite low, in which case you might try 1/4 tsp/gallon at every other watering. If you're NOT flushing the soil when you water, we'd need to rethink the whole thing.

Al

Thanks for the quick reply tapla. I read your posting on 5-1-1 soilless media and learned a lot from it. I decided to try the coir rather than the pine bark fines since it should last longer and it is less acidic (I think).

I did plan to flush the soil out a little each watering to wash out some of the salts that build up. I had read a post a while back stating that the instructions on a fertilizer container were alway the max amount you should safely use since the fertilizer company is in the business of selling fertilizer. It further stated to always use half the recommended amount so that is what I was trying to verify. I am using rain water to water with so I am assuming that just adding the fertilizer to the water and letting some drain through and run out the bottom each time is the correct method. If there is a better method, please let me know.

Tom

Some things to consider ......

Coir is the finely ground hulls of coconuts, the physical properties of which are very close to those of sphagnum peat, for which some would consider it to be an appropriate substitute. CHCs are coconut husks chipped coarsely, and would be closer in physical characteristics to chipped pine bark than peat or coir. Both coir and CHCs have some chemical properties that require special attention if you are to expect best results from their use. The higher pH of coir or CHCs you mentioned is probably closer to a negative than a positive because it eliminates the use of dolomite as a liming agent and as a source od Ca and Mg; this, because using lime raises pH to levels that can bind (make them insoluble) many of the micronutrients.

I agree that you don't always get good information from the advertising hype on fertilizer packaging. In fact there is no doubt that fertilizer manufacturers lead you to believe things that aren't true, and imply promises that their product can't deliver, but because they have a vested interest in helping us to not kill our plants so we remain potential repeat customers, their dosage instructions are usually on the low to middling side. I often use 2-3x as much 9-3-6 as the instructions advise during periods of peak growth (long days & temps from 60-80*). In winter, I thing the 1/4 tsp/gallon each time you water is realistic - as long as you are flushing the soil. If you would consider your light levels to be especially low, you might consider 1/4 tsp/gal every other time you water. If you're not flushing the soil when you water, everything is more complicated and difficult to maintain anything resembling precise control of.

Personally, I don't follow my own advice when it comes to watering, but here is the most effective way to water plants:

* Using a rose or nozzle that allows you to cover the entire surface of the soil, water until the soil is saturated, but no water is yet exiting the drain hole

* Wait about 10 minutes

* Water again, but this time until at least 15-20% of the water applied during both operations exits the drain hole

* Make sure the effluent in the collection saucer has no pathway back into the soil. This requires a positive disconnect between the soil and the effluent, even during the draining period.

This method flushes accumulation salts from the soil and prevents the ratio of nutrients in the soil from becoming badly skewed, the later of which happens quickly when you use fertilizers that don't closely mimic the ratio at which the plant actually uses the nutrients.

I use the method described except I do it all in 1 water application instead of waiting and flushing as the second operation.

The nozzle I made to use on the watering can - it helps me to accurately aim the water wherever I want on the soil's surface:
{{gwi:22144}}

Al

Thanks very much for the reply and detailed information. I used what was called coir which I knew was coconut husk but the particles were not very fine. There were several pieces I sifted out that were almost the size of my small fingernail. Most particles seemed to be about a quarter of that size or smaller though.

I knew it had a higher or less acidic ph but thought that to be a plus. I guess I messed up because to the 5-1-1 mix, which was only about a 4th of a 5 gallon bucket of media, I added 4 tablespoons of dolomite. Because of that, I will probably have a mix that is too alkaline.

Please let me know if my understanding is correct. A media mixture that is too acidic will not facilitate the absorption of the nutrients by the plant even if the nutrients are in the mixture. Is the same true when the soil is too alkaline? So, I guess the media mixture I have made is extra alkaline because of the dolomite I added so the Ca and Mg will not be usable.

I only have two plants that I repotted (both philodendrons) using this mixture and after a week, they appear to be strong so I will probably redo a soil mixture using pine bark fines and correct my mistake. What are your thoughts on this?

Lastly. I have obtained most of my information about houseplants from a book I bought used. That is "Houseplants for Dummies" which I am not bothered to say fits me perfectly at the present time. From reading it, it was my understanding that a plant should be flushed with water (alone) about every 2 to 3 months to prevent the buildup of the residues or salts as they are called. It also discusses adding a 1 teaspoon of white vinegar to a quart of water for a more effective solution to flush with.

After reading your comments, I was thinking I would follow the fertilizer recommendations exactly but only use it on every other watering. On the non fertilized watering, I would flush out the salts by allowing the water to go through the mixture and drain out the bottom, carrying the contaminants with it.

I feel lucky that I have been able to keep these plants looking good for over a month now. While attempting to figure out what I am doing! It seems to be somewhat like raising kids. That is another undertaking where one starts out with little or no knowledge. :-)

Thanks again
Tom

The 'ideal' pH range for containerized plants is about 1 full number lower than for plants in the ground. You can compare:
For mineral soils:
{{gwi:2916}}

For container media:

The issue is more P, Mn, and B's availability for uptake them Ca and Mg, which are increasingly available as pH rises.

FWIW - as long as you're using a soil that allows you to properly flush the soil, and you're being reasonable about how often you water, it's going to be hard to go too far wrong. I think that if you can get your plants exposed to good light, you'll be on a downhill run (that's a GOOD thing). I wouldn't be afraid to use that vinegar or some citric acid when you water for the plants in the coir with dolomite, either.

Take care.

Al