It looks quite awesome!

I would use a tablespoon of lime per gallon.

Nice job! I can see the happiest roots in that mix:-)

Mike

Yes, indeed, a good looking mix. As Mike says, add the Dolomitic Lime.
The bark is uncomposted. That's a minor deviation that will require more watering
up front - until the mix settles a bit and "binds." I've never used composted bark
in my 5-1-1, so you're in good company. I prefer the uncomposted bark because it
makes the mix last so much longer. Just be aware that it is a deviation.

How 'bout a shot of slow-release fertilizer?

Josh

Tip - generally, when you make the 5:1:1 mix, you're looking for bark that has some fine material in it, that has dust up to 3/8" material. The gradual variation in particle size helps to keep things homogeneous. I'm afraid you might get some stratification in your mix because of the abrupt disparity in particle size. {{gwi:20507}}
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The gritty mix, on the other hand, uses particles that should be fairly close to each other in size, which helps to prevent stratification and keep things homogeneous.

Still, you should see a marked improvement in root health in the mix you've made. As Josh mentioned, don't be afraid to use your fertilizer regularly, even in winter - and the lime Mike mentioned would be a good idea, too.

Al

Mike and Josh -- I went ahead and potted the lipstick plant and the rooted goldfish cuttings in the mix. I soaked the mix for a while before using it. After potting, I flushed with water until it ran out and then left it to drain. I love the look and smell of this mix. Thanks for reminding me about the lime. I looked for it on Saturday at Lowes and Home Depot but they did not have it. I will call a nursery and see if it can be located. Can I add it to the top couple of inches for the ones I have already potted?

Al -- I will look for bark that has different sized pieces. Is that what Josh meant buy uncomposted bark? I am having a difficult time finding small bark. I finally resorted to Petsmart and the Repti Bark. When I first wet down the mix, I worried about losing all of the peat to the bottom of the container but it seemed to stick to the bark and perlite fairly well. Can I add something to the remaining mix to decrease stratification? I now have perlite, peat, crushed granite, turface, pumice and this bark. Can I use this bark in the Gritty Mix?

Here is a photo of the lipstick and the goldfish after potting.

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This is an interesting (physics?) question: adding bark to the gritty mix. I might wonder if it would actually make your water retention worse? It'll decrease the surface area in the mix--and I assume since the gritty mix is all relatively similar-sized particle, adding a large medium to that, would break up areas that might collect water between them.
On the other hand, since bark itself can absorb some moisture, maybe it would increase humidity, while lowering water retention?
I'm just guessing here, as I'm still trying to wrap my head around the concept of perched water and water retention as a result of particle size (rather than how absorbent a material is!). It'll be fun to see what other (more knowledgeable) people say!

Ideally, the inorganic soil particles would be sized from about 1/10" to no larger than 3/16", and the bark fraction slightly larger, say from 1/8" to 1/4" to allow for some reduction in size over the life of the soil due to breakdown/composting.

PWTs disappear as particle size becomes larger than just over 1/10", so a soil with particles around that size maximizes the amount of water a soil can hold without it holding water between particles. This ensures a healthy root environment, free from the deleterious effects of perched water, from the bottom of the container to the top - even when the soil is at container capacity (holding all the water it can).

This is an interesting (physics?) question: adding bark to the gritty mix. I might wonder if it would actually make your water retention worse? It might not be exactly true, but bark holds about as much water as the average between Turface and granite combined. The aim of screening materials for the gritty mix to certain sizes is to ensure that as much water as possible will be held on the surface of soil particles and inside particles that are internally porous. What bark does to water retention depends on the size of the bark in relation to the other materials in the soil, how wet the soil is at watering time, and what mix of other ingredients are in the soil.

If you made a gritty mix of equal parts of screened Turface and granite, adding bark wouldn't change water retention much; but if the soil favored one or the other (Turface or granite), the bark could change water retention. If your soil was 4 parts Turface and 2 parts granite plus 3 parts of bark, the bark would decrease water retention; but it would increase water retention if the mix contained 4 parts granite and 2 Turface.

Also, even though it's very difficult to over-water anything in the gritty mix, letting your soil dry down some between waterings allows the bark fraction to work as a water reservoir and a sponge. When you water an almost dry gritty mix, the Turface sucks up water on contact - VERY quickly; but water pouring through the soil isn't absorbed as quickly by the bark. This is a benefit because any perched water quickly diffuses as gas (water vapor) and can be absorbed by the bark that didn't get fully saturated when you watered. If you water while the soil is still wet, the bark can become fully saturated and unable to absorb (sponge up) any excess water that might tend to want to perch near the bottom of the container.

I'm still trying to wrap my head around the concept of perched water and water retention as a result of particle size (rather than how absorbent a material is!). There is a difference between how absorbent a soil particle is and how absorbent a conglomeration of particles is. A tiny particle of sand holds water only on it's surface. Let's call that amount of water 'x'. You might expect that a conglomeration of 100 particles to hold a volume = to 100x, but actually it's much more than that because of the added water held between the particles. Once particles reach a certain size (about .1") water can't be held in the air spaces between the particles, only in the immediate area of contact between particles and on their surface. It's the size of the spaces between particles that determine whether or not they can hold water against the force of gravity.

All tiny particles (like fine sand/peat/compost) = small spaces between particles and lots of water in those spaces - more accurately - a tall PWT. All large particles (like BB size) = no water in the air spaces between particles and NO PWT. When large particles are mixed with fine particles, the fine particles surround the large particles, so the HT of the PWT and soil aeration is largely unaffected. This is why it's impossible to effectively 'amend' soils based on fine particulates by adding larger material, like pine bark or perlite. Unless the larger particles make up a very large fraction of the soil, the fine particles simply 'filter in' around the large particles and negate the effort - except as it relates to o/a water retention. You can see that if you add a fist full of marbles to a pint of peat moss, that the marbles will take up space and reduce o/a water retention without having any impact on drainage or aeration.

We know now that particle size has the most significant impact on o/a water retention, but only up until the point that the PWT disappears. A pint of Turface particles the same size as particles of fine play sand will hold more water than the sand because the Turface has internal porosity, but because most of the water is held BETWEEN particles, the increase in water retention isn't as great as it would be if the particles were larger, say .1". Then, there would be no water in the air spaces between particles and much water inside the very porous Turface particles, making the increase in water retention significant.
Got it? ;-)

Al

This post was edited by tapla on Thu, Jan 10, 13 at 21:17

Well written, Al, I'm adding it to my Clippings :-)

Incidentally, I've just come in from screening bark for my seed-starting mix.
I bought a bag of Turface yesterday, and two bags of bark today. Now it begins...

Josh

I have a question about the picture of the potting mix that Val posted. Can that same mix be used to repot philodendron, pothos, and chinese evergreen houseplants? What does the 5-1-1 ratio mean? I have only used miracle grow and bacto potting soils, and I think my plants would do a lot better in some other kind of potting mix. They aren't faring to well.

Thanks, Josh.

PT - Yes, that mix could be used to repot the plants you mentioned, and offers much greater potential for healthy root systems than soils that retain excessive volumes of water after the pot has stopped draining. If I was repotting any of the 3 plants you mentioned, without question I would put them in the gritty mix, which is equal parts of screened pine or fir bark, screened Turface, and crushed granite in a size range that finds almost all of the particles centered at from just below 1/8" to slightly larger than 1/8".

It's extremely durable (structurally stable), which is a very important feature of a quality soil, and guarantees excellent aeration, which is a key element of a healthy root environment, for several years - for much longer than it would be prudent to go between repots.

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"5:1:1" means 5 parts of an appropriate sized pine bark, and one part each of sphagnum peat and (preferably coarse) perlite. Well aerated soils require a commitment on your part to finding or making the soils, and a little more frequent watering. Once you locate the ingredients and are set up to build the soils, it doesn't take that much effort. The up side includes a much higher probability that plants will be able to grow much closer to their genetic potential on a healthy root system (they can't, on a compromised root system), and a lot less angst/effort to attain the degree of satisfaction and accomplishment most of us are looking for from the growing experience.

Much more info can be found at the link I left just below.

AL

Here is a link that might be useful: Click me & I'll take you to more soil info.

Thank you AL for taking the time to answer my questions. I would have had more questions, but I found the thread about suppliers for the ingr., and I found answers for what all the ingr. were, and where to start looking for them. Now, my only question is, should I wait for the spring(zone 8) to repot, or can I do it anytime? After reading all the info concerning potting mixes, I thought I was fairly smart about whats best....WRONG......... Thank you again for your help. Will let you know how my plants do,after repotting.

If I were you, and unless I thought the plant was circling the drain, I'd wait until at least Memorial Day to repot, Farther north, I'd wait until Father's Day. There are good times to repot, and not so good times. It makes no sense, from a horticultural perspective, to repot during the not so good times, unless the life of the plant hangs in the balance.

All my houseplants get repotted, along with all my tropical plants growing on for bonsai, between Father's Day and Independence Day. They recover much faster and are susceptible to fewer disease & insect problems if I repot then. The WORST time to repot is early spring. After a long winter of low light & usually dry conditions, the plants are usually at their lowest energy level of the entire growth cycle. Because days are longest around the summer solstice, plants are able to make the most food/produce the most energy at this point in the growth cycle, so they recover faster than at any other time.

Best luck to you. Let me know if you think there are any other questions I can help with. Take care.

Al

Thank you so much for your info. The reason I was asking about when to repot, I repotted some chinese evergreen divisions 2 yrs. ago, and I put 3 of the plants together into a 8" diam. pot, thats about 9" tall. The bottom leaves are starting to turn yellow on one of the 3 plants in that pot. I think now it was a mistake to put the plants in that deep of a pot. I think now I may have been overwatering, and the soil at the bottom was staying wet, and not drying out enough between watering. I kept up with when I was watering, every 3 to 4 weeks, until water ran out the bottom of the pot. I may have damaged the root system, I hope not. Probably should be using shallower pots? Two other divisions from that same plant are doing ok, I put them in a lot smaller pots. Thank you for helping me with my plants.

If you were using the same soil, shallower pots would compound the problem because the potential ht of the PWT is a constant, regardless of pot depth. A soil that supports 4" of perched water in a 6" deep pot will be 67% saturated at container capacity, while the same soil in a 12" deep pot would only be 33% saturated.

Al

Thank you Al, for your input. That makes perfect sense. All the more reason I can't wait to get all the ingr., and get all mt plants repotted. And then, hopefully, I will see my efforts rewarded with big, lush, beautiful plants, that I should have had a long time ago. Thank you.

If I make the 5-1-1 mix is it necessary to screen the pine bark like it is for the gritty mix?

Sometimes. It depends on what you buy & what % of it is actually usable.

Al

Hi all, I am trying to make my own 5-1-1 mix, but I'm having a hard time finding the ingredients. I need to repot a Ficus Lyrata. I live n Central America and the supply of ingredients is limited in the big box stores and garden centers.

I've not seen any pine bark. I've found Perlite, and I don't recall seeing any Sphagnum peat, let alone Dolomitic lime.

Here are some of the items I've seen can anyone tell me if you think it will work? Can I substitute plain dirt for the Sphagnum peat?

Thanks,

Luis

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