I just noticed I got this wrong. The mix is equal parts pine bark, Turface, and crushed granite, not perlite.

Alex

Howdy!

I've been using both of Al's mixes for several years now.

First, the 5-1-1 is 5 parts bark, 1 part peat, 1 part perlite.
With this mix, it is recommended to use slightly composted bark.

For the Gritty Mix proper, you want uncomposted bark, screened turface, and grit
in equal measure. This is a superior mix, offering an incredible amount of drainage/aeration
as well as durability. Your plants will outgrow the container long before the mix breaks down.

The Gritty Mix does not need to be refreshed each year, nor every two years even,
as long as the container is of sufficient size to allow for two year's of root-growth.
Re-potting should be done whenever the root-mass can hold all the soil together, but before
roots begin to circle the container.

Peat moss is disparaged for several reasons, primarily its small particle size.
However, it is also a pre-collapsed particle, which means that it offers neither structure
nor durability. When wet, it expands; when dry, it collapses (and compacts).
Peat moss is also difficult to wet when dry, and difficult to dry when wet. In a compacted state,
peat moss can actually "choke" roots. Roots will also die in the dry pockets that develop when
peat goes too dry and isn't uniformly re-hydrated. But it doesn't end there. Because peat based
soils (most bagged products) must be watered in sips to absorb moisture effectively,
the issue of salt accumulation develops. If one properly flushes a peat-based soil,
one then runs the risk of over-watering. Lastly, peat moss makes for a difficult
re-potting and root-pruning because it packs so tightly around roots. The longer one
has to expose roots while removing old soil, the greater chance for root-loss and/or
transplant shock.

As for Cacti and Succulent Mixes....read the package, they'll usually list peat moss as the
first ingredient. I made the same mistake when I started out, then I discovered Al's mixes.

Also, Perlite won't alter the drainage characteristics of a potting mix until the mix is primarily
Perlite (i.e. 80 percent of the mix or more). Perlite will reduce the overall water holding
capacity of the mix, so it's useful in that regard; however, this also reduces the room into
which roots can grow. Thus, another trade off.

Josh

Thanks for the advice, Josh and Ken. This is helpful.

Alex

I agree with Greenman - I have been usin it for about two years and what ever I use it for , the plants do well. I beleive it is esp good for conifers in containers. I plant conifers in hypertufa containers that stay outside and it works great. I do not need to replace the soil mix often.

If you read the post by Al in the container forum, there is lots of useful information. He also has some very useful information on fertilization.
We sometimes use too much fertilizer, and plants really dont need that much. Please read the posts. Best thing to do is try it on a sample of plants.

Here is a link that might be useful: Some stuff

Drainage is the key. I have been using Al's 5-1-1 for several years now. Big emphasis on drainage.

I use the Gritty mix in hypertufa contained with no loses - hosta, conifers, perennials.
Marshall

I've been using Al's (gritty) mix with pines, junipers, yews, and myriad other conifers for well over 20 years now, and though I do do a lot of experimenting with soils, have yet to find anything that works better. ;-)

I'm not self-promoting, just saying that I experiment with soils a LOT, and have yet to improve on the basic gritty mic mix. It holds LOTS of air, virtually NO perched water, ample volumes of water, is structurally very sound & durable, and it's adjustable for water retention to suit plants individually. Those are all the most desirable qualities you can have in a soil.

I wouldn't use wood chips other than conifer bark as a primary fraction of a container soil for several reasons. A pH spike during the composting process is inevitable. Wood chips break down much faster than conifer bark, so when using them, N immobilization should be expected. Also. because they break down so much faster, they generate a LOT of heat during the composting process, often raising sol temps an additional 10-15* higher than similar soils with bark as their primary fraction. Of course, N immobilization with the gritty mix is insignificant and heat build-up due to composting is never a problem because of how slowly the bark decomposes AND the excellent gas exchange of the highly aerated mix.

A 50/50 mix of a peat-based soil (like ProMix) and wood chips will yield a soil with the same drainage characteristics and perched water table height as the ProMix. Only when the wood chips (which are not a good choice for container media) are a very large fraction of the soil (about 80%) can you expect drainage & aeration to improve significantly. To get a visual on this, ask yourself how much perlite you need to add to a quart of pudding to get it to drain & hold air.

BTW - most commercial cactus mixes actually drain poorly & support way too much perched water to be healthy for cacti, succulents, or conifers.

All of the pines, junipers, and most other conifers I've grown would instantly rebel at wet media and the presence of significant amounts of perched water as the mix of ProMix and wood chips would be/have. They prefer a soil that holds little or no perched water and remains damp after watering instead of wet.

I have 320 lineal ft of bench space like you see in the picture below.

Most of the space is much more crowded with potential bonsai than you see, and conifers make up at least half of the near 300 trees. All are in the gritty mix; and I have no trouble keeping them happy & healthy.

Al

Al,

Nice bench pic, I like the pine at the top right, and the mix info is much appreciated!

I'm wondering how you overwinter potted conifers? Also, any chance for a photo tour of some of your conifers?

There is a bonsai and suiseki show in Denver next summer, which I am looking forward to!

Thanks,
Nate

Al,

Thanks for the info, and I love your potential bonsai conifers.

I have started repotting into square 1 gal "rootmaker" pots using the gritty mix. This should, hopefully, make for very happy conifers. One question I have is, should I wait until spring to fertilize (I would typically use Dyna-Grow Grow or Foliage)? Or is this medium so nutrient poor that something should be provided now?

Thanks,
Alex

That's a dwarf white pine that is destined to be a 'literati' style bonsai in a few years, Nate. I over-winter 75-100 conifers of various sizes, covering many genera in an unheated garage. Very occasionally (once/month?) I'll toss a little snow on the soil surface to keep the soil from getting too dry. In spring, they go in the shade (of my garage - on the north side - on a bench similar to that in the picture) for a week or so, then get moved to a full sun position when there's a day or two of cloudy weather forecast.

Alex - the Rootmaker pots + the gritty mix will yield some really happy plants.

You need to fertilize very regularly when growing trees in containers. Best, is if you shoulder the ENTIRE responsibility for ensuring your plants get all the nutrients essential to normal growth, and your FP fertilizer will do that very well.

I fertilize right up until winter really hits, and don't withhold or reduce the amount of N(itrogen) supplied, as many suggest you should. (Who does that for Mother Nature?) ;-)There seems to be some sort of forgone conclusion that you should stop applications of N as fall approaches. You'll find mostly anecdotal evidence suggesting this as appropriate, but little, if any, scientific. In some circles convention dictates we only fertilize while plants are in actively growing, or from bud break - late summer. I often see it contended that late (fall) feeding of N is sure to 'force' new growth and the new growth will be killed by frost.

Please consider that bud set occurs in mid-late summer, and while it takes N to fuel new growth, N plays no role in the initiation of bud-break. For that stimulus, look solely to photo-period, which also holds largest sway over branch extension.

The acquisition of resistance to chill is related to both photo-period and decreasing temperatures and is actually improved with regular balanced N supplementation, so there is no reason not to continue supplementing N through fall and into early winter. Let your guide be soil temperatures. As long as soil temps are >55* plants will assimilate and store not only P & K, but N as well. This (tendency to store N) plays a pivotal role in fueling new growth in spring when soil temperatures are reduced and assimilation of N is depressed. BTW - please do not fertilize with organic sources of N like various meals, fish/seaweed emulsions, or urea when soils are cooler than 55* (ammonium toxicity).

Al

Al,

Speaking of winter, what are your thoughts on how much dormancy conifers require, and does it vary among genera?

Thanks,
Nate

It varies by species, genetic coding, & cultural conditions. Generally speaking, evergreen conifers enter a true BUD dormancy, but maintain the ability to carry on photosynthesis and root growth when conditions are favorable; even some (branch) extension can take place during the dormant phase.

Al

Maybe the term I'm looking for is vernalization, or something similar. The idea that some conifers need an occasional period of exposure to cold. If deprived of a chill period the plant will lose vigor. I'm wondering, if I put a Picea pungens in a refrigerator for a month in October, would that be enough? Then bring it back to room temperature for the remainder of the winter? The goal would be to use it as understock for grafting in the fall.

Once trees enter full dormancy, which is brought about by a combination of decreasing photo-period and increasing chill, they require a certain amount of chilling, measured in 'chill units' to release them from dormancy. It's convenient to equate 'chill units' with hours of chill, but chill units are a function of both time AND temperature with units accumulating faster at temperatures between 35-40 than at temperatures below 35 or above 40*. Usually, you can get some rough measure of the number of chill units a tree needs by its zonal hardiness, but not always. Usually, trees hardy to lower zones need longer periods of chill to release them from dormancy.

I think that if you put the tree in the fridge for a month & then try to overwinter it indoors, you'll have a dead tree in short order. Frost-free refrigerators are very dry, and indoor conditions are very inhospitable to trees. I'm not an expert on grafting, but it would make more sense to me to do your grafting when sap was rising in spring as opposed to fall when turgor is minimal, but since I'm on shaky ground here with the grafting observations I might be off the mark. I'll leave that to you & your research or others better versed in grafting conifers than I.

In any case - I wish you best luck in your endeavors. Take care.

Al

Al,

To date, the grafting I've done has been in the winter/spring. One issue I'm running into is that in the typical scion collecting months (e.g. feb, mar) certain trees in the mountains are unreachable to winter road closures.

One thing I've been thinking about doing is collecting scionwood in the fall (when the tree is reachable), putting the understock through a brief forced chill period, and then grafting.

In the past, I've grafted as early as January, bringing in potted Picea pungens from the outdoor potyard into the basement grafting chamber. It seems to stress the plant, but some have made it. I'll probably try to push that envelope a little farther, so I appreciate knowing what factors are involved. If I figure anything out, I'll report back.

Thanks,
Nate