A Discussion about Houseplant Soils (long post)

oh--great--those are great ideas!

Friends, look at what I found called soil conditioner! It is just pine bark! I have been using it for years in the ground in my bad blackland clay soil but didn't know what it was until now.
It is made by Texas Pride in New Waverly, Texas.

This particular bag has been outside for months which may account for it being so moist. I think it may be the right size. The photo is taken with the closeup setting.

Wow, what a thread. I just read most of it in one sitting. I have learned a great deal!

I am now dubious of any soil concoction I have previously used for my office plants; I would probably have to look pretty hard to find any of the above ingredients here (but I'm not doubting the value of the efforts).

If I were to create a new container for my office (low light plants -- I don't have any windows), could I succeed with not having a drain hole at the bottom, instead achieving drainage via wicking? I ask because the container I have in mind would work much better on my desk if I didn't have to worry about water draining from the bottom.

...which leads me to my next question: if drainage is so important, even for bagged container mixes, could the same be accomplished by installing a "grate" of hardware cloth (or similar) a half inch or so above the bottom of the container, therefore providing a place for water to go?

Sorry for the odd questions, but I must live up to my title of "king of the jury rig".

Yours,
David

... could I succeed with not having a drain hole at the bottom, instead achieving drainage via wicking? I ask because the container I have in mind would work much better on my desk if I didn't have to worry about water draining from the bottom.

Well - wouldn't you need a reservoir to wick the water to? You'd need to have a wick that extended from the bottom of the container up and over the side & it would be necessary that the wick hangs below the container bottom. This would necessitate that the container holding the plant be elevated and another container provided to collect what is wicked away, so it just wouldn't make sense.

... if drainage is so important, even for bagged container mixes, could the same be accomplished by installing a "grate" of hardware cloth (or similar) a half inch or so above the bottom of the container, therefore providing a place for water to go?

That you provide a piece of screen that is raised above the container bottom is no insurance that the water will suddenly decide to vacate the soil you're using. As far as drainage, there is no difference between a hole in the container bottom and a screen - the water will react the same way except for one important difference. If the soil that you are using supports a saturated layer of soil that is (as an example) 3 inches deep, the saturated layer of soil in the container with the hole will extend 3 inches above the container bottom, while the saturated soil in the container with the screen will be measured at 3 inches above the screen. You would simply be causing the water to "perch" above the screen, instead of the container bottom, which, in effect, only reduces the usable volume of soil in containers in the same manner that other "drainage layers" like packing peanuts & stones do. It's an ineffective attempt at increasing drainage.

Read the post this link http://davesgarden.com/community/forums/t/719569/ will take you to for a more thorough understanding of what I just said.

Al

For anyone needing STEM, it can be ordered through Southwest Fertilizer in Houston. The cost is 5.95 a lb. or 25 lbs for under 75.00. Cicada and I ordered a lb. each and the shipping was 9.91 for her and 9.34 for me here in Texas. It gets shipped through parcel post which he said would take a week to Kentucky.

The telephone number is: 713-666-1744

****edited to say the STEM came today by UPS

This message was edited Jan 9, 2008 8:11 PM

Thanks Al, I read the thread (incidentally, I had replied back in May and had forgotten about it!) again.

I will need to go on a search for the correct ingredients. I don't mind watering more often (after all, I'm here every day except weekends).

Regards,
David

This is great! My cousin in Houston went to SW Fertilizer and bought everything she needed to make her own soil and is so excited about it! She also bought a 3-1-2 Miracle Grow liquid fertilizer. I didn't see the instructions for houseplants on the side so I have the darkest greenest african violets you have ever seen.

When I did find the instructions, I knew that Tapla would have been saying, "Slow down, Gail".......it hasn't hurt them but the instructions do call for only 1 tsp to gallon of water. When you fertilize the reservoirs of water for the african violets we are supposed to use about 1/4th of what is recommended......still laughing at my avs.

I just found a local source for Turface. The stuff sells for only $8.50 for fifty pound bag. So I'm happy about that. I should be able to find the rest of the stuff for Al's mix fairly easily. I'm becoming more and more of a convert that this peat based potting soil that we are all using is just crap. I take care of a hundred container plants at the place where I work, and shortly after a plant has been re-potted the soil is completely broken down and becomes a hindrance to the plant. I can't wait to get away from that stuff as I'm sick to death of re-potting, because the soil has collapsed and is worn out.

Doug

I've been growing in it for years, Doug, and I know you'll be glad you decided on a well-aerated mix with durable ingredients, though it might take a little tinkering (mainly with your watering & fertilizing habits) to get to the point where it pleases you perfectly. If durability/longevity is your goal, the gritty mix is by far the best. Plants will need potting-up or root pruning/repotting long before you find any soggy soil issues with that mix.

Good luck.

Al

Thanks Al for all the effort you put into this potting soil issue. You are really making a difference.

Doug

Yesterday, I was doing some research, trying to help out a person who had contacted me by e-mail. As I was searching the net, I found a fertilizer that was unknown to me, but now after having learned of it, I'm very excited about it. I'm not sure how long it's been on the market, but it has a 3:1:2 ratio and a full compliment of all the minors. It also has only 1/3 of its N in ammoniacal form, so for those who put their plants outdoors - cool weather and/or periods of low microorganism activity shouldn't cause problems with (often undiagnosed) ammoniacal toxicity like the fertilizers deriving their N from urea.

I'm not going to link to it directly, but you can find out more about it by using the search words Foliage-Pro 9-3-6.

After studying the label, I can tell it's a well-thought-out fertilizer because the % of nutrients soo closely matches plants' actual usage, and by the fact that all the nutrients are available in the proper ratios to prevent antagonisms (between nutrients, which can cause uptake problems). The manufacturer has even made allowances for nutrient levels normally found in container media.

Take care

Al

With my new outside mix I planted hanging baskets and pots all yesterday........just love the new mix but can't move today as i am too sore. I also hung all my epis and hoyas in the trees........so pretty in bloom........

Ok Al,

I've found the Turface MVP for your gritty mix, but what I'm not able to easilly find is the Turkey Grit made of granite. The Grit I've found by calling around is medicated or has other minerals mixed in. It is possible that feed dealer could order it in, but it is almost $20 per bag. Is the granite absolutely necessary for the mix or could I use just the Turface and the bark?

Thanks,

Doug

Forget the last question. I just found the Turkey Grit, and only $9.50 per bag. I'm very excited that I'll finally be able to make the mix in the next couple of weeks.

Doug

It's used to adjust the water-holding ability of the soil. If you increase the % of Turface & decrease the granite, the soil holds more water. Less Turface & more water yields less water-holding ability. Try a masonry supply store for very coarse silica sand. It should be 1/2 BB size or larger. You might also find it at a place that sells swimming pool supplies. Tell them you want the coarsest sand they have/can get.

You can get by w/o it by experimenting with different volumes of perlite in its place, but when included, it makes SUCH a nice soil. ;o)

Al

OK - got it.

Al

I can't find the bark. The only bark I'm finding is mulch and is way to big. Any suggestions?


Debbie

I drove 100 miles round trip on Friday and bought 6 bags of the Turface MVP and I have the Turkey Grit. Now I am on a quest to find the perfect bark; I hope that I have better luck than you Debbie. It is still pretty cold around here, and much of the bark and mulch is not out yet or is frozen so I haven't been able to really look yet.

Doug

Around here the major brand that is sold everywhere is Jolly Gardener. Some of their mulches look OK, but many of them are dyed black or red, and I want to avoid that if possible. I don't know what the long term effects would be from this dye when used as a growing substrate. They have a great website showing all their mulch configurations, but I'm not sure yet if everything they make is available in VT. I'm only at the earliest stages of looking; however, I want to get this mix right the first time.

Doug

I found the perfect pine bark but it is packaged as soil conditioner. Mine is made by Texas Pride but look around your area for soil conditioner. The size of the bark is perfect to use.

Thanks Gessiegail; I'll look for it. I am determined to find the right stuff to make Al's mix.

Doug

This is my version of Al's soil. I found some pine mulch last night that did not look too bad and mixed a small batch of the soil. It still is not perfect, but I'm anxious to begin experimenting with it. I think that if I want the perfect size bark, I may have to order it on line, which I have found on Bonsai supply sites. It is not like I need a huge amount of the soil as I am only planning on using it on my indoor ornamentals. Any how, the stuff sure looks and feels different than anything I am used to, but I have a good feeling about it. I think this could be a whole new beginning for me as far as indoor container growing. I have always had great success, but only because I am a frequent re-potter.

Doug

The soil structure looks wonderful, Doug - strong work! Are you sure it was pine or conifer bark? Wood products from hardwoods or with lots of sapwood can cause some significant N immobilization, so you may need to watch for that.

Al

Thanks Al. It said pine mulch, but who really knows what else is thrown in there. I was a little concerned about the N immobilization as well, and threw out as much of the big pieces of wood as I could find. It also did not say pine bark mulch just pine mulch. The only real strictly bark stuff around here appears to be Pine Bark Nuggets and you could choke and elephant with that stuff. Each piece is two - three inches in size. Even the stuff that says Orchid bark is far to large to be used. This stuff appears to be the best compromise that I can make for right now until I order the Pine Bark Fines from an online source.

Doug

Here is the URL of the stuff I used. It does say shredded Pine bark, but are there laws governing how much other stuff gets in there? I don't know.

http://www.jollygardener.com/mulches_pine_mulch.htm

Well, although it is way too early to give a definitive report on using Al's mix, I have to say the results are encouraging thus far. I have re-potted (washing off as much of the old potting mix as is feasible) around a dozen Hoya plants (95% of what I grow at home) with the new mix. These were mostly plants that have been problematic for me - very easy to over water and rot the roots, many were cuttings from plants that had to be started over for that very reason. None of the new plants have gone downhill from the re-potting, and one particularly sensitive one is already producing new growth in the week since the re-pot.

Other observations: This gritty mix only holds about half to one third as much water as the peat mix I was using. I know this because weighed each pot before and after watering with a very accurate digital scale. The mix weighs roughly double regular potting mix, so when you are used to just picking up a pot to see if it needs watering, it will totally throw you off. Until I become more used to the mix, I am weighing the pot to see if it needs to be watered. The water runs through the mix very quickly, which means that you need to be set up to accommodate that fact by watering over a sink or having your plants on an egg crate in a tray, or some other means to allow the water to go somewhere. Otherwise you will be emptying a lot of plant saucers. I think I will have to water two to three times as often, but that is not necessarily a bad thing if it produces healthier roots and thus a healthier plant because of it. Even though it is very early, I thought I would write down my initial reactions to the new mix, and will report periodically on progress.

Doug

Somehow I missed your last post (with the link), Doug. Sorry about that.

In one respect it takes more time and effort to grow in fast soils, but from another perspective, I've found the increase in vitality of the plants goes a loong way toward minimizing other problems like insects, disease (including root rot), nutritional deficiencies associated with wet soils, and all the other troubles that a lowered level of vitality brings; so, the effort on one end kind of balances out the effort it would take to correct the troubles on the other end.

Glad you're encouraged - do report back, please. ;o)

Al

Al,

I made a huge leap of faith this weekend and re-potted 80% of my plant collection (around 40-50 plants - I lost count after awhile) into the gritty mix. I'm hoping for good things. I know one thing for sure; the root systems of these Hoyas that I grow looked, with a few exceptions, terrible. I had many plants with virtually no roots left, or very unhealthy looking roots. When I got these cuttings, I used rooting hormone and put them into a propagator with straight perlite as the rooting medium. After a month, they all had wonderfully healthy white root systems where upon I planted them into my usual peat mix to which I added liberal amounts of perlite and bark. Now six to eight months later the roots look awful.

I have had some success growing these plants, but with every success, there are a couple of miserable failures. Sometimes the leaves get limp - deadly, the only way to save the plant is to take cuttings and re-root; sometimes the new growth dries up, which many of us call stick syndrome, and sometime the plant just sits there and does nothing. I think many of these problems if not all of them are directly related to the unhealthy conditions of the roots. I am truly hoping that many of these problems will begin to vanish with this new potting medium. I will report back every couple of weeks with an update. My fingers are crossed!

Doug

Doug - what did you use as a Ca source in the mix? What is your fertilizer of choice? If it is not complete with all the secondary macros and all the minor elements, how do you intend to supply them?

Al

Al - I'm using a product called garden lime in the mix to provide the calcium. The fertilizer that I use is a complete one developed by Michigan State University specifically for soil-less mixes. Many Orchid enthusiasts use it, and refer to it as MSU. It is available in two formulations - one to use with tap water and one to use with rain or RO water. I use the tap water version at a 1/2 teaspoon per gallon every time I water and flush the soil with pure water on every third or fourth watering. The fertilizer can be found at this link: http://www.growinhydro.com/21332.html

Doug

OK - Just checking. It looks like a superb fertilizer - wanted to be sure you had all the bases covered. ;o)

Al

Thanks Al! I appreciate it.

Doug

Al,

Do you have any helpful hints on determining when to water the gritty mix? I know it must vary considerably depending on environmental conditions, but I could use a little guidance. I've lost all ability to judge from hefting the pot, because this stuff weighs 2-3 times the weight of the peat-based mix I've used all of my life. The surface of the pot looks dry 12 hours after watering, but dig down a little way and it is very wet. I've weighed the plants dry and wet, but weighing each pot every time to determine if it needs to be watered is a little tedious, and I keep second guessing the scale which I probably should not do. Putting your finger into the mix to judge dampness is not working for me, because it feels dry, but I don't think it is - if you can believe the scale or look up through the drainage holes and it looks very wet.

I've only lost one plant so far, which was no big deal - I was not particularly fond of it any way, but when I pulled it out the soil looked dry on top, but was soaking wet on the bottom. It had a large drain hole in the bottom that I partially covered with a piece of broken crockery. This stuff is so foreign to me; it is very hard to know when to water. I'm constantly afraid I'm going to over water or under water, and right now it looks like I erring on the side of watering too much. I'm not ready to give up on this stuff yet, but could use a little of your wisdom in working with it.

Doug

For JuneyBug:

If you have particular questions, I'll do my best in answering them.

Al

I'm just absorbing it all right now.
I now know why GessieGail's gessies and AVs are sooo great looking!
I knew my soil was too wet, and now I know why!
This is so radically different than what is conventionally understood.
It seems to be the answer my plants needs.
I've bookmarked this so that I can come back to it often.

Thanks so much.
June

Tapla,

I located this thread and realized that it goes well with another of your threads that I just read.. I am learning so much here at DG and I appreciate your input.

Hoya (if you're still following this thread) - I just got a D-Mail pointing out that I had neglected your questions a little upthread and asking a couple additional questions. I don't know how I missed your question, but I'm sorry.

One easy way to tell when you need to water plants in the gritty mix is to feel the soil at the drain hole. You can insert a short wick into the drain hole, and when it feels dry, it's time to water. After just a short time, you'll develop a 'feel' for when water id needed & you won't even need to check the wick. Most plants can go 3-5 days between waterings indoors, but that is a pretty broad generalization, so make sure you figure out what works best for you.

'Diamond' also asked "What type of fertilizer do you recommend?" and " Can this same mix be used for outdoor potted plants?"

If I had to choose only one fertilizer that I would apply to all my plants, I wouldn't hesitate for a second to choose a fertilizer with a 3:1:2 RATIO. MG and Peter's both make 24-8-16 granular soluble, MG also makes 12-4-8 liquid, and Dyna-Gro makes Foliage-Pro 9-3-6, which has all the micro-nutrients in a favorable ratio. It also has Ca and Mg, which are lacking in most soluble fertilizers. All of the fertilizers I mentioned are 3:1:2 ratio fertilizers, and the Foliage-Pro 9-3-6 would be my choice.

Yes, the soil works very well outdoors, I grow all my long term woody plantings as well as other plants that will go 2 years or longer between repots in the 1:1:1 soil of Turface, crushed granite, and pine bark.

Al

Thank you, Al, for all this wonderful information. I like to know what I'm talking about when dealing with customers at work (which has now effectively come to an end for the season). Many of the questions are about fertilizers and I know mostly the basics. The soil and fertilizer info is quite valuable and I will certainly put it into practice with my own plants. Unfortunately, most people just want basic information until they are more experienced or comfortable with either houseplants or gardening. I can see their eyes glaze over when I become too detailed with instructions, so just try to have a simple answer to get them going, with hopes they will have success and will return when they have a bit more confidence and experience. The best thing to teach them is to "feel" when the plants need watering and I try to 'show' them what this means.

How can I bookmark this page on this site? I'm a Mac,don't know if that matters. I know how to do it from my "general use" toolbar but didn't know if there was a way to post a link on my DG home page.

Click the tiny manila folder in the upper right hand corner of this page. that will take you (and this page)to "tags" where you will name this tag and it will be put into YOUR files.