Has anyone compared results of using Tapla's gritty mix vs a CHC-based mix in growing citrus in a cold climate (like New England)? From my readings so far the principles are similar, with the primary difference being the degree of detail available regarding mix formulation and "tweaking". Also, it appears the coconut husk has better long-term stability.

I had been depriving citrus roots of air for over 15 years using Miracle Grow potting soil, and it has worked exceptionally well in that regard. Coupled with my "loving" watering practices, it's almost a miracle that ANY citrus survived my care, and few did.

Thanks to another forum and this one, I can look forward to filling my sunroom with fragrant blossoms, fresh (FREE) fruit and the satisfaction of finally succeeding thanks to the education that experienced members are providing.

Going from my killer-soil to the gritty mix has been somewhat surreal, since the gritty mix doesn't "feel" like soil. But, after 2 1/2 weeks, my Four Winds citrus is doing fine. Using a sharpened dowel to check for moisture has been eye-opening, and it's hard to believe the trees are still fine when the surface of the "soil" feels like dry aquarium gravel.

So, thus the questions.....Which medium is more forgiving? (If I leave on vacation in January, which one will forgive an overwatering neighbor?) When I repot, what benefit or drawack (either cultural or personal) is there from changing? Lighter pots? Higher/lower frequency of watering in the summer? Longer-lasting before repotting?

I can't imagine a whole forum with people using one soil mix and another using a different soil mix without a plethora of comparisons. I see no "need" to change, but am curious as to the differences.
Tanksalot
Stan F.

Tanksalot, welcome to The Citrus Growers Forum. We are excited to have you as a member. Some years back I grew citrus in a type of gritty mix very similar to Tapla's. It worked well, and the trees had very little trouble. The only "problem" might be that gritty mixes are quite heavy. About 8-10 year ago I begun experimenting with Coconut Husk Chips (CHC), as a medium for container citrus trees. I added various secondary ingredients such as peat moss, choir, compost, and even Spanish Moss. Eventually, I settled on 4 parts CHC and 1 part peat moss. A couple months back, I had four trees that that needed to be transplanted into larger containers. I transplanted them into Rootmaker Product's 50-gallon Air Root Pruning containers, using large (1 to 2 inch) CHC and Miracle grow potting soil. (I agree with you Miracle Grow Potting Mix is a terrible product when used by it self. It quickly compacts and drives out all the root zone aeration. However, with large CHC to break it up it works OK). Both Tapla's mix, and a CHC mix, share the two important primary properties absolutely required by container citrus trees. That is, both mixes drain well, and both mixes supply the tree's root system with excellent aeration. Most any type of blend that drains well, and has a high level of porosity, whatever the ingredients, could possibly work well for citrus.

The reasons, that I prefer to grow my citrus trees (100+ different varieties) in CHC are:

1). Coconut Husks Chips holds moisture up to 7 times it weight, therefor I don't have to water as often as with a gritty mix.

2). It has excellent drainage.

3). CHC is very durable - last up to 5 years.

4). It is a very stable carbon source.

5). CHC has the optimum pH required by citrus - 6.5pH.

6). Provides the critical moisture-oxygen balance.

7). It is made from a renewable resource.

There is no perfect growing medium for containerized trees. Every medium has pluses and minuses. The goal is to find a medium that has as many benefits as presently possible, with the fewest number of minuses. JUST A NOTE OF INTEREST: The number-1 medium used commercially WORLD WIDE is 3 parts pine chips (or other conifer bark), plus 1 part good peat, and 1 part sand.

Again welcome to the forum Thanks for becoming a member. - Millet (791-)

I agree with Millet , for me was a great deal switching to CHC mix

Danero2004 - What mix did you use before the CHC mix?

Tanksalot
Stan F.

Millet:
Thanks for taking the time to formulate a concise, detailed and "professional" reply (that was the most appropriate word I could think of). I've got the CHC ordered, and will thus be compelled to purchase more citrus in order to compare and satisfy my curiosity.....as well as my fascination with citrus.

Thanks again

Tanksalot

Tanksalot, from what source are you purchasing your CHC. The pre preparation needed for citrus could be different depending where you purchase the CHC. - Millet (790-)

The Crystal Company in Missouri. I'll be getting the Ca(NO3)2 on ebay.

The Chrystal company has the best CHC available. They pre-wash their chips and squeeze dry them under high pressure three times. Besides removing much of the salts, it also put many small fissures in the chips, which allows the chips to quickly absorb water. When you soak the chips in Calcium Nitrate, also include a little magnesium sulfate. - Millet (790-)

Stan,

I experimented with using the Ace hardware CHC chips (search for my other posts here) and sure enough, unless I did the Calcium Nitrate + Magnesium exchange process my tree experienced leaf tip burns from the excessive salts; it was revealed within 2 weeks of planting. I had quadruple rinsed that particular batch (I soak, then just compress them by hand while rinsing, then soak again). I have seen no signs of burn on any of the trees I rinsed + did the Calcium Nitrate Cation Exchange on.

My next batch of CHC will certainly be from Crystal. To answer your question:

BOTH seem to be forgiving of temporary over-watering (ie neighbor during vacation). I still find it hard to believe the CHC/peat mix is forgiving from over-watering (i.e. has some aeration left), since when you water. that mix sucks up an incredible amount of it, much more than the gritty mix. But I did some testing by over-watering for three weeks and I did not see any signs of damage. With MG mix, I can see early signs within 2 weeks of over-watering.

My local hydroponic store did a test by taking the same plant types and placing them in various soils in a container without drain holes, then filling the entire container with water. In a very short time the typical potting mix plant died, followed later by a mix with some CHC, then lastly by an entirely CHC mix. Combine that with Millet's comments about CHC and I'm guessing there is something to the CHC holding pockets of air internally, despite being submerged in water.

* Prep: The biggest difference with the gritty mix is obviously in preparation: gathering the components and the sifting required. There is some work to the CHC but not nearly as much (just the CEx soaking if bought from Crystal).

* Weight: The granite in the gritty mix makes it heavy weather you've watered recently or not. But a recently watered CHC mix is nearly as heavy as gritty IMO.

* Temps: I think the gritty mix is more susceptible to colder temperatures (i.e. the root zone is colder in winter). The flip side might be it is also cooler in summer, both due to the larger macro-pore (aeration) and thus lower water content between particles.

* Price: The difference in price for the gritty mix can vary tremendously, depending where you live and access to the ingredients. Whereas we are all ordering CHC from the same place and the price of peat (or bagged MG mix) is fairly close in the lower 48.

I have access to all three (standard) components of the gritty mix almost as cheap as they come at retail. If I recall correctly, I can build about 2CF of mix for approx. $47. The CHC from Crystal Company is $55 for 4cuft (per Millet, Crystal Co says it can be up to 6cuft expanded) plus a bag of peat or small bag of MG for $4 bucks more. One time costs for CHC: Epsom is cheap, but the Calcium Nitrate will cost you about $20 medium bag (you probably won't use more than 1 cup full) unless you get it from a friend

* Cold Winter: I live in Zone 9 so I can't speak with any experience here.

Hope it helps,
Chris

Why don't you use fine grain cocohum instead of peat moss?
/Robert

I don't know what cocohum is, but if you mean coir, the answer is you can use equally either peat or coir. - Millet 769-)