Foliar Feeding

Nan's Nook : Archives : Botanicals : Cactus : San Pedro : Growing San Pedro
Posted by: ion Jul 20 03, 12:23 PM GMT
This is kind of a cut-and-paste (with editing) of some discussions I've been having in public and private.

Foliar Feeding Cacti:

There is an average of about 2 or 3 inches of rainfall every month around here, so I never water with plain water. If you don't get this kind of rain, then just substitue every 4th feeding with plain water instead of fertilizer water.

I am presently using 2 tbsp of Peter's All-Purpose (20-20-20 w/ chelated micros), 1 tbsp Calcium Chloride (Damp-Rid®), and 1 tsp of Superthrive to every 5 gallons of water. I allow the water to de-gas (chlorine) for a day in a translucent bucket in partial shade, then I mix in the fertilizer and such in the evening. I feed the cacti at night, by ladling the water over the surfaces of the plants (foliar feeding). I feed about every 3rd or 4th night, and I pour a little bit in the pots after it rains, too.

Every 3rd feeding, I reduce the Peter's to 1 tbsp and add a tbsp of Urea. On the fourth feeding (the one you should replace with plain water if you don't get rain) I feed as above, once. On the 5th feeding, I add 2 tbsp of Hydrated lime to the water. Then the cycle repeats. angel.gif

Every month during heavy feeding (late May to early September), I dump a bit of powdered dolomite (a type of limestone with high magnesium content) into each pot. There are smooth pebbles on the surface of the soil, so when it rains, the powder isn't just splattered out of the pots. It gets washed in between the rocks and down into the soil.

On a dim cloudy day (never water the surfaces of a plant in bright sunshine... this can magnify the light and burn the plants), you might try foliar feeding and find that the water just beads up and rolls off of the plants. At night, you will notice that the water "sticks" to the surfaces... this is because the stomata or "pores" of the cacti are open and they are able to absorb gases, water, and nutrients through the skin at this time. The base of the cactus may be "sticky" for water almost all the time... This is probably because the waxy cuticle in that region has worn very thin over time, but likely not because the stomata are open.

Benefits and conclusion:

I foliar feed all of my cacti at night... this gets the nitrogen (for alkaloid production), calcium and other nutrients where they need to be and also gives the roots time to soak in goodies before the day's heat. wink.gif

I've noticed my cactus flesh is getting more and more bitter-tasting since I've been feeding this way... even the fresh growth tips have more flavor than they did when I was only root feeding. devil.gif

I've also noticed that old cacti with grafts on top seem to get really concentrated with bitterness due to the lack of their own tip-growth.

Alkaloid production is a function of time in these plants... the more time an area of the flesh has to remain alive with no real new growth (think about how slow peyote grows), the more concentrated the alkaloids become. This is due to an odd form of nitrogen fixation in the flesh... the alkaloids are nitrogen-containing molecules. So, if nitrogen (in your fertilizer) is directly absorbed by the green flesh, there is a great chance that this will be much more nitrogen than is needed for growth, and that the plant will "fix" it by producing more alkaloids. biggrin.gif

Taste the flesh of new pups, old growth, and tip-growth on your pedros... you'll see what I'm talking about, and you can even monitor the effectiveness of foliar feeding on your own. wub.gif

Posted by: anok Jul 20 03, 02:13 PM GMT
cool,i'll have to try some cacti foliar feeding.
yucca root extract might be of some benefit also,its sticky and holds everything on the surface until it can be absorbed,maybe just boost the efficiency a little, i guess its a surfacant.

Posted by: CockyMandrill Jul 20 03, 02:38 PM GMT
It has to be doing something if you can taste the difference, I'll have to start foliar feeding soon, sounds like it could make for some potent healthy cacti.

Posted by: ion Jul 20 03, 10:48 PM GMT
Indeed. biggrin.gif

You don't need any sticky stuff, anok. The little water that flows over them and stays for the night will be plenty. I'd be worried about clogging the stomata if something other than nutrified water were applied.

In fact, any sticky pest repellents (like soapy water with stuff in it) should be applied during the day. This way, the pores can open up at night and "split the sheath" of goo. wink.gif


Posted by: Samsara Jul 20 03, 10:57 PM GMT
Thanks Doc! wub.gif

Ion you continue to amaze me. biggrin.gif Thanks for the info, I will have to start feeding at night.....

Keep up the research, I love it and I am sure the whole cacti community does too! biggrin.gif

Posted by: ion Jul 20 03, 11:51 PM GMT
The seed of the foliar feeding concept was planted by Bob Roberts... in regard to helping cacti get plenty of calcium before cutting (I've found it aids in scab formation and hardens them off from rot). wub.gif

I just figured to apply the concept to increase alkaloid production (once I learned exactly how alkaloids are made) and promote general health and growth speed. wink.gif

The flavor of some of my foliar fed graft stocks (I sample it every time I cut off those energy-redirecting axillary pups) is so bitter I can barely stand it... but I chew it up, anyway. biggrin.gif

It might be interesting to see what happens if I foliar feed my control plant and only root feed my experimental (dopamine in DMSO) plant. Wouldn't it be great if alkaloid production was the same in both plants, and both were higher than a non-foliar-fed plant? ohmy.gif

It's like killing 7 birds with one stone... overall health, disease resitance (also cleans off any rot-culturing honeydew), growth speed, nutrient and water uptake for cuttings, pulls heat out of the plant surface so that nightly reactions (CO2 fixing) reach optimum temperature more quickly, cleans the surface of light-blocking dust and soil bits, and to top it all off, it increases alkaloid production! laugh.gif


Posted by: entheopharm Jul 21 03, 03:11 AM GMT
Great read as usual ion! nerd.gif

I foliar feed just about everything outside, but I never foliar fed my cacti thinking it couldnt make much difference. Thanks for clearing that up biggrin.gif Now it makes perfect sense!

Posted by: Akasha Jul 21 03, 07:05 AM GMT
Excellent research and detail, ion! I reformed my watering method beginning last night. Thank you!

'These guys are good' biggrin.gif

Posted by: CockyMandrill Jul 21 03, 02:43 PM GMT
Does superthrive cause a noticable difference ion? If so I'll make sure to pick some up.

Posted by: Bob Roberts Jul 21 03, 05:57 PM GMT
Very good, Ion! It would be interesting if we could dig up some research about how long it must be dark for the stomata to open.

Keep this kind of thing coming!

One thing that we need to be sure of is that there is not an excess of water regularly going into the substrate so as not to encourage root rot. A mister/pump sprayer would probably also work.

Posted by: Fungusmaximus Jul 21 03, 06:19 PM GMT
Ive been using Ions advice about foliar feeding for bout a week now on some sunburned peyo pups and they have totally turned around! The cactus was looking better after the first night!
Damprid calcium is great for sunburned cactus! Ive foliar fed every night since. Note that I have a huge power fan blowing 24/7 I dont worry too much about overwatering or rot.

Posted by: ion Jul 22 03, 12:42 AM GMT
I haven't had a noticable difference in growth from Superthrive, yet... but I've only been using it for about a month. I have noticed, however, that my cacti seem to have fewer incidences of rot spots (bug bite induced or otherwise) and those that do occur heal very quickly (leaving only a tiny scab instead of a big one) since I started using Superthrive. If I had to give numbers, I'd say about 50% less rot and 75% faster healing. wink.gif

From what I can tell by the adhesion or beading of the water on the surface of the flesh, the pedros open up just after mid-dusk. Other cacti open up earlier or later, but all are open before midnight, which is when I water. cool.gif Peyote (grafted) seems to open up even when the day is dimmed by heavy clouds... so I dunno how accurate a gauge the "beading" concept is for cacti with less cuticle than pedros... or at least for slow-growing cacti that are grafted (it's possible that the forced growth creates greater interstitial area between cells, making them seem to be open when they are not).

Also, I've noticed that growth tips always bead up... perhaps stomata must reach a certain age or position on the cactus before being allowed to open at all. This may be some defense against greater heat and/or air movement as elevation increases... I have no clue, but I always try to associate behavior with plausible evolutionary adaptation. think.gif

I used to worry about root rot, too... but during the hot season, all of my pedros (and most of the other cacti) fare excellently in constantly moist, basic soil... they just don't seem to care at all.

One thing: I've noticed that diffusa seems slightly less water and sun tolerant than pachanoi or williamsii. I've been keeping her under shade, out of any rain, and only watering every other time I water the cactus garden... she does great this way. wub.gif


Posted by: MajorBuzz Jul 22 03, 09:31 AM GMT
Mescaline production is at it's maximum during dormancy, right? If so, then I would assume that we should spray the cacti with a solution of Peters or other nitrogen rich fert during the winter months. What do you think?

Posted by: ion Jul 22 03, 04:18 PM GMT
That's not exactly what I meant with the post I believe you are referring to, buzz... I'll explain:

During dormancy, the cacti should not be taking up any water or nutrients at all... so don't feed them or water them during this time... doing so may break dormancy or, worse, encourage rot.

In the beginning of dormancy, the cacti seem to take any excess nutrients in the flesh and use them up or "fix" them if they can't be used (without sun or proper temps)... this means that alkaloids can be produced even without growth of the cactus. The rate at which this is done may not even be significant, but I believe it does happen, just from my observations and insight as to how alkaloids work.

By the end of dormancy, the cacti have dehydrated a bit, and thus the overall concentration of alkaloids is higher by weight... same concept as drying mushies: dry is more "potent" than fresh, due to a lack of water being accounted in the weight.
This is only of interest if the cacti are going to be extracted without water, as it is just a reduction of mass needed to be extracted.

Alkaloid production may benefit with a foliar spraying of fertilizer just before going into dormancy, but certainly not during the dormant period.
However, you only want plain or basic water to get into the soil... fertilizer the soil just before dormancy can lead to rather acidic soil conditions... this may really hurt the plant.

Do you see what I mean, now? smile.gif


Posted by: ion Jul 22 03, 04:37 PM GMT
BTW, folks... in case you are wondering, it is a bad idea to use a fertilizer with higher nitrogen than either phosphorus or potassium on cacti. This will not enhance alkaloid production any more than using a balanced N-P-K fertilizer.

for instance:
20-10-15, or 20-20-7 is not good... it is better to use 20-20-20.

Too much nitrogen can cause yellowing and/or "hollowing" of cacti. Yellowing is self-explanatory... Hollowing is a condition where the center of the pith becomes a hollow hole or tube. The cacti can survive this, but the condition can invite disease and pests to live in the center of your cactus (think about evil squirrels in a hollow tree tongue.gif ). I'm not sure why this happens, but my guess is that the excess nitrogen is probably in the form of ammonia gas... since it cannot be usedas quickly as it is coming in, this evolves into bubbles which are released into the interstitial spaces, eventually separating the cells and forming a large cavity.

I have noticed that heavy alkaloid producers are less prone to this condition than those species that do not make many alkaloids... I'm even thinking that this is one reason why they evolved to make alkaloids in the first place, and not terpenes or some other poison!
Nevertheless, I have seen pedro with the hollow condition... I now own a crest of this particular cactus. This was brought on by way too much nitrogen and no basification of the soil.


Posted by: Archaea Jul 28 03, 02:19 PM GMT
Genious, seriously genious.

Lets see this worked into a seedling tek where a dilute nutrient solution is sprayed on the seedlings during the dark period, I will give a few batches of pedro seedlings the treatment and compare. If some cytokinins were in the spray it might be possible to get grafted speeds with plants on their own roots.

I have noticed some of my cacti seem to absorb water through the spines or areoles during the day, I have often wondered if the Ca and Mg salts in my hard water were absorbed this way.

I too use the peters 20:20:20 because it has an awesome macro/micro formula. I use it at every watering in the growing season at a rate of 1/4 tsp per gallon with great results, I bet with even better results once I implement the foliar method.

The foliar feeding is brilliant. A surfectant couldn't hurt but shouldn't make as much of a difference as it does with leafier plants.

Posted by: CockyMandrill Jul 29 03, 02:21 PM GMT
I'm really interested in the long term benefits of this, it should give optimum nutrients for mescaline production so we would have very very good potency. Who knows, 1 ft might be a super strong dose from foliar feeding.

Posted by: ion Jul 29 03, 08:40 PM GMT
wink.gif I dunno about super strong... but anything's possible! ohmy.gif

Thanks for having faith in me, folks. wub.gif


Posted by: Archaea Aug 05 03, 03:35 PM GMT
I have noticed quick results in the "glow" of the cacti from foliar feeding allready!!!

I used Peters 20:20:20 at 1/4 tsp per gallon without a surfectant.

Honestly they "blued" up even more almost overnight, and I am stoked!!!

I am going to try this on some seeds I just planted and compare to a control group. I will spray about 400 pedro seedlings nightly and leave a control group of around 100. I will try to post the results.

Posted by: ion Aug 05 03, 08:14 PM GMT
Wow, thanks! biggrin.gif

I love to see the results of others' experiments... especially experiments similar to my own! wub.gif


Posted by: Bob Roberts Aug 05 03, 08:49 PM GMT
Bet ya Nitrate Nitrogen would work better than Ammonia-containing Nitrogen!

Posted by: ion Aug 06 03, 02:31 AM GMT
Bet ya it would! wink.gif
...and it is much less likely to give the cacti that "nitrogen splitting" problem I'm always going on about. biggrin.gif

BTW, folks, nitrate nitrogen sources are notoriously better at increasing alkaloid production than ammonia-based nitrogen sources! devil.gif

Thanks for mentioning the nitrate, Bob! I would have totally forgotten about that little alkaloid tidbit! wub.gif

*edit: I just remebered that cacti don't like much sodium at all... so no sodium nitrate... maybe potassium nitrate or something like that...
...makes me wonder what's in Peter's. huh.gif


Posted by: MajorBuzz Aug 06 03, 12:33 PM GMT
So where do you find nitrate nitrogen?

Posted by: CockyMandrill Aug 06 03, 02:40 PM GMT
peters is 2% Nitrate Nitrogen 18% Urea

Posted by: ion Aug 06 03, 02:45 PM GMT
I'm looking... smile.gif

Peter's and all the other combo ferts like it use mostly Urea nitrogen... damn...


Posted by: CockyMandrill Aug 06 03, 02:53 PM GMT
Hey ion, have you ever heard of this?

Hydrogen peroxide is added to foliar feeding solutions, fertigation, irrigation, etc., to improve oxygen levels. Higher oxygen levels improve the plant's ability to take up any available nutrients.

Just a lil info i thought that could possibly make foliar feeding even better.

Posted by: ion Aug 06 03, 03:07 PM GMT
Huh... huh.gif Never heard of that. Maybe we should ask Bob...

Bob? biggrin.gif

It doesn't make any sense to me... plants use CO2 for photosynthesis, and expel O2... I would think an over concentration of O2 surrounding the plants would hurt them (by not allowing O2 to escape by leveling the diffusion gradient) or not do anything at all. Not to mention that peroxide can hurt any exposed healing tissues... it won't hurt the skin, though, and it would probably reduce the chance of infections by killing bacteria and spores on the surfaces.

If we use anything, seltzer water would be more appropriate... but dissolved CO2 creates carbonic acid (this is why cola will eat a nail in a few days). The acid may not be too much for the soil if properly limed, but I worry...

Again, Bob? huh.gif


Posted by: CockyMandrill Aug 06 03, 03:14 PM GMT
heres the benefits
What Are The Benefits?
Not only is oxygen a major component of the plant structure itself and one of the main elemental nutrients the plant feeds on, it also performs many important functions within the plant participating in all metabolic processes. Adding H2O2 will provide extra oxygen to help with all these functions including:

helping to oxidise metallic elements to make them available for plant use.
helps root uptake.
helps with transport mechanisms within plant structured.
helps stimulate protein production at a cellular level, enhancing photosynthesis.
helps break down the carbohydrates created through photosynthesis.

Posted by: ion Aug 06 03, 03:26 PM GMT
There's no question that it will help if applied to roots; that's why we want aerated soil, after all.

I just don't think it would do much good in foliar application... except maybe when it soaks into the ground. tongue.gif

It would help if we ladle the water over them, IOW, but not if we spray only enough to coat the plants.

So like I said, if you decide to try it, just don't let it touch any exposed flesh (like from wounds)... peroxide makes the inner flesh turn brown (oxidation like a bite from an apple) after a minute of contact.


Posted by: ion Aug 07 03, 07:29 PM GMT
Man... did I find the motherlode or what!? Check it out!

[URL= ii: soil fertility management]FERTILIZER INFORMATION[/URL]


Posted by: Archaea Aug 08 03, 03:11 PM GMT
Some orchid specific food contain a bit of Nitrate N, but they tend to have some ammonia as well.

There is an ingrediant in peters with sodium in it, I forgot what it is but I saw it there this morning. Still I like the results.

Posted by: Bob Roberts Aug 08 03, 07:32 PM GMT
Sources for nitrate nitrogen

Potassium nitrate (KNO3) -- soluble and basic

Calcium nitrate [Ca(NO3)2] -- soluble and basic -- the Peter's Excel 15-5-15 Cal-Mg fertilizer I use contains 11.75% Nitrate Nitrogen, 2.05% Urea Nitrogen, and 1.20% Ammoniacal Nitrogen. In addition, there are micronutrients. When I pulse fertilize at 200 ppm N, I'm giving 66 ppm calcium and 26 ppm magnesium and this fertilizer combats the effects of high sodium in your water. I love it, I use it on everything at the nursery, and I have no complaints other than Nitrate nitrogen is readily leached out of the soil and when it rains I have to go back with a higher rate. Plus it's more expensive.

Edit- oops forgot Ammonium nitrate (NH4NO3) -- soluble and acidic

Then you've got Sodium nitrate (noone really uses it) and Nitric Acid (to lower pH and alkalinity)

As far as the hydrogen peroxide thing goes, I've heard of it being used in hydroponics quite a bit and in some sensitive, pre-disposed to root rot plants. I couldn't say how it would affect the cactus, however I'd say that a solution shouldn't ever go over 3% and it would probably be better to start lower than that. It does drive chlorine out of the water. Probably would be better using it on the soil, but worth a try anyway!

Posted by: ion Aug 08 03, 11:21 PM GMT
That fert you're using sounds pretty good, Bob! Where can we get some? huh.gif

In all my searching, I've been looking for a 1:1:1 ratio fertilizer with only nitrate nitrogen (calcium nitrate, potassium nitrate, and magnesium nitrate, specifically) plus all of the sugar acid chelated micros.

I can't find any fertilizer that meets this standard. huh.gif

I'd love it if you could direct me to a good database or just a fert like this, Bob... I'd also like to get in on some good soil fungi, too. wub.gif

Thanks! biggrin.gif


Posted by: Bob Roberts Aug 09 03, 01:13 PM GMT
The reason why we use low amounts of phosphorous is because in soil-based media, phosphorous is relatively immobile. In soilless media, phosphorous is readily leached when there is a high irrigation rate and low pH. For that reason, if you are concerned with having an evenly balanced fertilizer, I would suggest using this Scotts Excel 15-5-15 Cal-Mg and adding some Triple Super phosphate, but it's really not necessary to do that but once a year. Another thing to think about is that the use of mycorrhizae greatly increases nutrient uptake, especially phosphorous.

If you are looking for a professional, 1:1:1 fertilizer, try a 15-16-17 Peat Lite Special. They usually contain higher amounts of Nitrate nitrogen, but are acid-forming. So, you would want to figure out the potential acidity and correct it with liming applications.

Hey, was just doing some searching and found a site called talking about using the Scotts Excel 15-5-15 Cal-Mg!

"Use a water- soluble, nitrate based, fertilizer like Peters EXCEL, 15-5-15 cal-mag with trace elements that cacti love. We then greatly reduce the concentration recommended by the Peters company and use only 2-3 teaspoons of Peters per 5 gallons of water"

There's a link for buying the Miracle Gro Excel. It's good stuff.

Posted by: ion Aug 09 03, 02:14 PM GMT
Once again, Bob... you rock! biggrin.gif

So wait a minute... is every professional 15-5-15 Cal-Mg fertilizer out there subtitled "Excel"?? You mentioned Scotts, Peters, and Miracle Grow... all with "Excel" after the name... huh.gif

Are all of these fertilizers exactly the same?

I'll go hunting on those websites and run some searches. Thanks, man! smile.gif

Oh! So are you saying that if mycorrhizae (that's a toughy) are used, we shoul reduce the feeding schedule?


Posted by: Bob Roberts Aug 09 03, 02:24 PM GMT
Twas a monopoly at once, Ion! Read this

Basically the same stuff, IMO. The Miracle Grow is made by Scotts who, I believe owns the Excel technology. So you are really getting the same product essentially.

Yes, mycorrhizae do reduce the need for watering and fertilizing. The presence of P suppresses mycorrhizae growth, which has prevented the potential use of them to improve plant growth in commercial operations.

However, I have a sneaking suspicion that Monrovia Nurseries has found a way around this as have some others

Posted by: ion Aug 10 03, 01:17 AM GMT
Well that explains a lot... in the past, I was having trouble figuring out exactly what company "peters" was... huh... thanks again. smile.gif

That stuff really is expensive, man! You weren't kidding... ohmy.gif

That site doesn't even say what size bags it's selling... kinda frustrating. :\

We need to find something that is available at normal retail locations. I'll see what I can come up with.


Posted by: Bob Roberts Aug 10 03, 04:48 PM GMT
I'm sure that price is for a 25 lb. bag, Ion. That's the only size I've seen. As far as finding it retail, I'd say that your best bet is to go to a reputable nursery and have them order it through their hardgood supplier. It's worth the effort. Just tell them you are growing some plants at home and don't have a commercial license. You won't go through this stuff very fast. To make 1000 gallons @ 250 ppm N, we use 14 lbs. So, say you're doing like a 100 ppm N constant, that's like less than 7 lbs (/me doesn't feel like doing math now) for 1000 gallons of solution. It equates to probably 2/3 -1 year supply of fertilizer for your cacti. Just remember that $27.00 is about average retail for 25 lbs.

Oh, and I'd highly recommend Hummert for supplies if you can't find them locally. Haven't used the online ordering, but they probably have everything you want to make your fertilizer mix, Ion. Course I don't have to remind you about what makes what precipitate, eh? wink.gif

Posted by: ion Aug 10 03, 05:38 PM GMT
Sweet! But I'm not going to thank you again... don't want to get all redundant! tongue.gif

Heh... I understand general precipitation theories, but their are definitely things out there that don't seem to follow along the normal lines of thinking. For instance, take two salts that will dissociate in the water (ionize) completely, but even if the two salts are neutral (not strong base, like KOH or something), it is still possible for the opposing ions of each salt to combine into something that will precipitate... it happens slower than an all-out A/B neutralization reaction, so you don't notice the problem immediately... it's pretty annoying. :/

So it's always good to have a list handy of what salts not to mix in water together, even if you know what does what... there's always a possibility that you may forget and waste a bunch of expensive salt, by accident! sad.gif

I'm assuming, oh grandaddy of plant know-how, that you have one of these types of lists... please share it with the rest of the class! biggrin.gif


Posted by: Bob Roberts Aug 10 03, 08:33 PM GMT
Heh, appreciate the flattery, Ion. wub.gif So, here is something that I have on my desk and just typed up for ya.

Posted by: ion Aug 11 03, 12:04 AM GMT
Typed?! You sicko... wub.gif

Thank you ever so much my good man! Now I can print this out and glance at it while making purchases... biggrin.gif


Posted by: Archaea Aug 11 03, 06:07 PM GMT
Very cool!

Posted by: Toad Aug 15 03, 05:10 PM GMT
Have been following thread closely(nice link's guys) and started to foliar feed some of my pedro's before work . These are all cut pedro's and no tips.
I leave before 5:30 AM so it's plenty dark.
I have been using the same nutes that I mist on all my plants.
This is the maintenance dose of:
Dyna-Grow Grow 7-9-5, 4.4% Nitrate Nitrogen and 2.6% Ammoniacal Nitrogen. With all essential trace elements.
Pro-Tekt 0-0-3 (The Silicon Solution). Contains 3% Soluable Potash from potassium silicate, and 7.8% silicon.
The added silicon in the Protekt is supposed to reduce stress caused by heat, cold, drought, insects and diseases. Blah, Blah right off the bottle.
I have noticed when misting that the droplets are very pronounced and stick evenly on all angles of the pedro if applied evenly and lightly. How Obsessive Cumpulsive is a ladle, pfft. It's quite beautiful if you take the time to notice. wink.gif
The pedros that have been sprayed are plumping up visually and rigid to the touch in just over a week.
The rate is over twice the uptake as the others. This is producing more baby spots than the other group IMHO.
I have not seen the bluing as described with the damprid.
SO.. I gotta get some. Let's see 5 bucks for a enough to water my lawn. tongue.gif

Posted by: ion Aug 16 03, 01:08 AM GMT
Glad to hear it, toad! smile.gif

Contains 3% Soluable Potash from potassium silicate, and 7.8% silicon.

Potash is Potassium hydroxide.  I think it means 3% soluble potassium... but it's hard to imagine any silicate mineral being very soluble at all in normal water.  Is that stuff acidic?  I'm confused... huh.gif
Silica sounds like a good idea, but only if the plant can actually use it as a foliar thing... it gets most of that from soil, I think.  See what you can dig up, if you would, please. think.gif

How Obsessive Cumpulsive is a ladle, pfft. It's quite beautiful if you take the time to notice.

What?! laugh.gif
The droplets are pretty, yes... but I'm not sure what you're talking about, here. laugh.gif

I think the bluing is from nitrogen. The ferts most others and I are using are balanced even across NPK. That may have something to do with it. Not sure, though. What makes a cuticle turn blue, Bob? smile.gif

Damprid is good, but be careful if using a pray bottle... there are some precipitates of calcium, and they can clog a sprayer up mighty quick! Just dunk your hand in the bucket of the water, ferts and damprid... when it dries, you'll notice it is crusty... you'll also notice that it is difficult to wash this crust off! wink.gif


Posted by: Toad Aug 16 03, 07:53 PM GMT
The silicon: from Overgrow.

Pro-silica: (Soluble Silicon)
”… increases resistance to pathogens by accumulating in…(leaf and root) cells of plants, providing a barrier against penetration by invading fungi such as powdery mildew and Pythium….Foliar applications leave deposits of silicon…on the leaf surface that promote effective physical barriers to…infection.”. Pro-silica is also alkaline.
Tank: 1ml/gallon/with each tank change
Foliar spray: 1 part in 5

And here's a long advertisement driven read. biggrin.gif

I switch out my nutes with straight water every other foliar spraying and have seen no visible accumulations on the cacti exteriors.
I brought up the evenly spaced droplets as a testiment to the way the cacti open stomata are working before dawn.
I have some sunburn issues on a button that I will address with the damprid. Picked up today. wink.gif
And in leau of and in addition to Bob's answer on Nitrogen; What is a good sourse of straight nitrogen?
I have blood meal but don't like the idea of attracting varments or is that an issue?

Posted by: ion Aug 16 03, 11:52 PM GMT
Straight nitro to cacti can be a bit finnicky... too much and they can literally pop! ohmy.gif

Nan uses Urea. I just use 20-20-20 ferts. I have used the urea, but I dislike the pretty drastic change in pH. I dunno... I'm looking for a cheap potassium, calcium, magnesium nitrates mixture. biggrin.gif

Nitrate nitrogen is probably best for our purposes (plant growth and alkaloid production). Do not use sodium nitrate. Cacti dislike sodium.

That stuff sounds interesting. Where do you get it and how much does it cost?

Cacti already use lots of silica. Recently we had a discussion about whitish silt at the bottom of some syrup... this was likely silicate structures from the cells. It's possible that silica could hinder filtration a bit, but if it helps the cactus, then I think it's worth it. smile.gif


Posted by: ion Aug 17 03, 12:04 AM GMT
Here's my info on potassium silicate:

Additional Names: Soluble potash glass; soluble potash water glass

Literature References: Variable composition: K2Si2O5 to K2Si3O7; may also contain water.

Properties: Colorless or yellowish, translucent to transparent, hygroscopic, glass-like pieces; strong alkaline reaction. Usually very slowly sol in cold water, or depending on the composition, almost insol. More readily sol in water when heated with it under pressure. Insol in alcohol; dec by acids with precipitation of silica. Keep well closed.

Use: As binder (e.g., in carbon electrodes, lead pencils, protective coatings, insol pigments); detergent, in glass and ceramics manuf.

Looking at this, I gather that it needs to be dissolved in warm water and with no ferts present. think.gif
I'm learning that not all potassium silicates are created equal, however...

Posted by: ion Aug 17 03, 12:14 AM GMT
The agricultural grades of this stuff are incompatible with reactive metals (Aluminum, Zinc, Tin, Lead), acids, and ammonium salts.

It can evolve Hydrogen gas on contact with the metals, creating an explosion hazard.

It will react and precipitate silica with acids. This silica isn't very nice... it is glass powder, and will cut you.

It will evolve ammonia gas in contact with ammonium salts... this means do not mix it with fertilizers containing ammoniacal nitrogen sources!

Posted by: Archaea Aug 17 03, 02:38 PM GMT
I use DE in my mixes for Si. I figure that organic acids dissolve some, does that sound right?

I know that grasses tend to have fairly high silica content and composted grass clippings make a great soil-mix ingrediant.
Do you think that there is appreciable soluble Si in manure tea?

I notice the tissue in the creases between the ribs seems to be getting darker with the foliar feeding.

Also I have sprayed some of my seedlings with the peters 20-20-20, at this stage (2 weeks) there isn't any noticable differance.

Posted by: ion Aug 18 03, 01:48 AM GMT
DE does have a basic pH when it is not "acid washed", so I'm assuming this is from some amount of silicate salts in the DE. The thing is, "silicate" is the conjugate... silicic acid is the substance that we want and it is bound to a very strong "base" ion when in silicate form... this is why solutions of silicate salts are basic and not acidic. If there are acids in the water when you add the DE, they will likely replace the silicic acid in the silicate compound and force the silica (unbound silicic acid degrades to silica in the presence of acids) to precipitate and become mostly unusable by the plants. Silicate compounds are an odd example in electrochemistry, and they aren't easy to pin down (like NaCl, for instance).

I'm a little inebriated, so please bear with me. blush.gif

There may be some good silica levels in manure, but I don't think this form of silica is very soluble... so not much would end up in the tea.

Yes, the inner rib darkening is a good sign. smile.gif

No, I don't notice any difference with seedlings, either. I think it's due to the simple fact that they really have no surface area... water just beads up into one giant bead and rolls off tongue.gif
In fact, even ferting the soil for seedlings doesn't do too much. It helps a tad, but only if you're really paying attention. I think seedlings are so small that they do just fine with the little bit of available goodies already in the soil. smile.gif


Posted by: wizeoldgnome Aug 18 03, 05:22 PM GMT
can i assume that foliar feeding should cease with the watering for the dormant season.(im getting pretty bummed guys,fall/winter is right around the corner. this has been a great growing season for me, thanks to you all)

Posted by: ion Aug 19 03, 12:04 AM GMT
Yeah... all feeding should stop. sad.gif

It's been a good year, though. Had some problems, but all went pretty smoothly looking back. wub.gif

It ain't over yet... wink.gif

I may have some absolutely stunning things to show you all by the end of this. biggrin.gif

...and I may have some things up my sleave for reducing this whole dormancy thing... devil.gif

Posted by: wizeoldgnome Aug 19 03, 06:23 AM GMT
ohmy.gif huh.gif biggrin.gif -waits in anticipation-

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