The Never Ending Abuse of Phosphorous (Bloom foods) to Enhance Flowering

[burnonehomie]

I wrote this years ago and thought I'd share it here.

The never ending abuse of Phosphorous to enhance flowering

A common mistake for growers when they reach the flowering stage is to start hitting the plants with a high P fert like a 10-50-10, continuing to use this blend exclusively, and when their plants start experiencing a deficit of N, Ca, Mg or micros as reflected by the dropping of lower leaves and chlorosis, they wonder why. Plants flower as a response to long nights, not because of fert blends high in P. A ratio of 10-60-10 is WAY too high in P. The plant will only take what it needs and compete for other elements that may be more important at the time.

You may have heard that too much N can inhibit flowering. No question about it, exclusive use of a plant food that is rich in N such as blood meal, a 5-1-1 blend, or ammonium nitrate/sulfate may inhibit flowering especially if the phosphorous level is low, but most balanced blends have sufficient amount of P to do the job. The question is - "how much P is enough to support a good flowering response and still retain my leaves?"

Manufacturers/horticulturists will give you element analysis and what effect the elements have on plant growth, but remember this does not necessarily mean you will get better yields. Using a high P fert exclusively during flowering can actually work against you due to impending leaf drop. It's an abundant amount of healthy leaves going into 12/12 and maintaining their health that produces a lot of bud, not high P ferts.

I rotate fert blends as the plant *requires* them, not because it is "the thing to do." For example, when your plants are going thru the stretch phase during early flowering, they may need more N, especially if you're getting some yellowing in the lower leaves. Give up the cannabis paradigms and give them what they need. Go back to mild high P fert when the stretch ends, maintaining the foliage in a healthy state of growth until harvest for maximum yields. A 1-3-2 blend such as Peter's Pro Blossom Booster, 10-30-20, is one of the best flowering blends on the market because of several factors - it is higher in nitrate N and Mg. It is sold under the Jack's Classic label. An added benefit of Peters blends is their use of high quality, very pure salts that will eliminate root burn if used judiciously.

Uncle Ben

nice post. +rep

 

[Uncle Ben]

Although there is
no specific research, it appears that applying between
10 and 20 ppm phosphorus with every irrigation will
supply enough phosphorus to a plant (any plant, not just
orchids) for normal growth and flowering. Once this
sufficient level is reached, then there is not any
particular benefit to applying any more phosphorus.
Thus in this case, there is no benefit to using a high
phosphorus fertilizer.

Yep, this principle goes full circle back to my original thread post when I said - The question is - "how much P is enough to support a good flowering response and still retain my leaves?"

Glad you enjoyed itburnonehomie.

Change gears. About 30 years ago I bought a 1962 book called General Viticulture by Winkler. Yesterday I dusted off that book and while reading the chapter on pruning techniques, which goes into the botany of it all too, guess what point was made regarding vine vigor and capacity? That's right, leaf mass and I quote:

The capacity of a vine varies directly with the number of shoots that develop. The TOTAL LEAF AREA, not the rate of elongation of the shoots, determines capacity.

That translates across all plant material lines,where leaf mass drives "capacity" or the propensity of a grapevine or any other plant to produce high quality yields, as well as support root growth and other plant parts.

Again, your goal as a grower should be to produce and maintain as much leaf mass until harvest for the best yields.

UB

 

[wyteboi]

Here's another really important point, balancing foods with water quality:

First, the ideal fertilizer for any crop, not just
orchids, is one that balances you water quality.
Probably the most important aspect of this comes with
the management of the substrate pH. .......That means that the amount of acidic nitrogen should be balanced by the alkalinity of your irrigation water.

My well water is neutral in pH, but the alkalinity is high (high Ca bicarbs), so, the 21-7-7 that I sometimes use is a good choice.

...and........

In addition, an ideal fertilizer should supply a
sufficient amount of each nutrient for growth. That
means that the nutrients contained in the fertilizer
should complement those supplied by the irrigation
water. If the water does not contain a specific nutrient,
like calcium or magnesium, then it needs to be supplied
by the fertilizer. It also needs to be supplied at a
concentration high enough that it influences plant
growth. For example, some 20-10-20 fertilizer contain
magnesium, but the amount supplied is so low that it
really doesn’t influence the nutrition of the plant.

Thanks for the links and info!
I am reading on nutrition and am going to read everything on that site , i imagine.
I am already starting to think the RO/DI water is a waste of time? Its lacking important foods and from my understanding it is "starving" for ions. So i imagine when i use it, it throws the food into a frenzy until the ions are back where they are meant to be? that could change the properties of the food , i guess?
Sorry guys , i get a lil obsessed with my fish and plants
My guess is , if i mix or bubble the ro with a lil tap (or even by itself) for a couple days prior to mixing food in (or topping the fish tank off) the ion thing should fix itself. I know alot of this shit is unnessacary to know , but it will all help me in the long run.
You guys already saved me from gettin too far lost in the bottle/forum bullshit. I am back to the old ways now and my babies love me for it.
This is one of the best threads on the net.

wb

 

[wyteboi]

Again, your goal as a grower should be to produce and maintain as much leaf mass until harvest for the best yields.

UB

^^^^^ That is what it all boils down to.
I can agree and honestly say i have the hands on to prove that one.

wb

 

[DaveCoulier]

Thanks for the links and info!
I am reading on nutrition and am going to read everything on that site , i imagine.
I am already starting to think the RO/DI water is a waste of time? Its lacking important foods and from my understanding it is "starving" for ions. So i imagine when i use it, it throws the food into a frenzy until the ions are back where they are meant to be? that could change the properties of the food , i guess?
Sorry guys , i get a lil obsessed with my fish and plants
My guess is , if i mix or bubble the ro with a lil tap (or even by itself) for a couple days prior to mixing food in (or topping the fish tank off) the ion thing should fix itself. I know alot of this shit is unnessacary to know , but it will all help me in the long run.
You guys already saved me from gettin too far lost in the bottle/forum bullshit. I am back to the old ways now and my babies love me for it.
This is one of the best threads on the net.

wb

RO isn't a waste of time. The low EC of it is still quite beneficial. You just should balance your water source with your fertilzer. You can cut RO water with tap water. Anywhere from 50-50, to say 70-30. Not sure which range would be best though.

I know if using RO we often add Cal/Mag supplements to the water often to add back what was lost, but does the addition of Cal/Mag into the RO water form carbonates and bicarbonates? Thats something Im not versed on.

Wheres Kriegs when you need him

 

[Uncle Ben]

Like I quoted before, the fertilizer and water quality (profile) must complement each other. If you use tap water and soil, then you can get by with something like Peters which has about 8 elements and no Ca. If you use RO water and basic water culture, then you need something like Dyna-Gro that supplies 16 elements, in sufficient quantities to where they'll do the plant some good.

 

[Kriegs]

RO isn't a waste of time. The low EC of it is still quite beneficial. You just should balance your water source with your fertilzer. You can cut RO water with tap water. Anywhere from 50-50, to say 70-30. Not sure which range would be best though.

I know if using RO we often add Cal/Mag supplements to the water often to add back what was lost, but does the addition of Cal/Mag into the RO water form carbonates and bicarbonates? Thats something Im not versed on.

Wheres Kriegs when you need him

Right here. This thread is daily reading for me.

The simple answer is "yes". Whenever you have H2O and CO2 together (always, in real life), you will have bicarbonate. Whether added Ca or Mg will make more depends on your water pH after RO. Assuming a 6.5 pH or thereabouts after RO, you will get some formation of Ca and Mg bicarbonates.

There's a pH "sweet spot" for bicarbonate formation between 5-ish and 7.5ish. Lower pH than 5 favors free Ca/Mg and less bicarbonate. Higher pushes towards true carbonate formation (like calcite - CaCO3)

In the general sense, Ca, Mg, pH, CO2 and bicarbonates are all links of a single chemical chain. When dissolved CO2 is rising, pH is dropping, and Ca and Mg dissociate from the carbonate ion (CO3) and become available. Degassing of CO2 will increase pH, and drive the equation toward precipitation of solid CaCO3 (calcite), or Ca(Mg)CO3 (dolomite).

I've skipped over a few things, but that's it in a nutshell.

What we want as growers is to get Ca and Mg to our plants. I imagine these supplements are slightly, maybe substantially, acidified to keep the ions freely available until you use them. The acid buffers inherent in soil, or the hydro operator will keep the pH in a range that keeps enough of the Ca and Mg ions free. Only at pH's beyond 8.0 would you have to worry about your added Ca or Mg locking up with something and not getting to your plants.

 

[Kriegs]

BTW, the answer to my previous Q on where to get nitrate N?

Dyna-gro.. Peters, too... no wonder you love that stuff..!

 

[DaveCoulier]

Right here. This thread is daily reading for me.

The simple answer is "yes". Whenever you have H2O and CO2 together (always, in real life), you will have bicarbonate. Whether added Ca or Mg will make more depends on your water pH after RO. Assuming a 6.5 pH or thereabouts after RO, you will get some formation of Ca and Mg bicarbonates.

There's a pH "sweet spot" for bicarbonate formation between 5-ish and 7.5ish. Lower pH than 5 favors free Ca/Mg and less bicarbonate. Higher pushes towards true carbonate formation (like calcite - CaCO3)

In the general sense, Ca, Mg, pH, CO2 and bicarbonates are all links of a single chemical chain. When dissolved CO2 is rising, pH is dropping, and Ca and Mg dissociate from the carbonate ion (CO3) and become available. Degassing of CO2 will increase pH, and drive the equation toward precipitation of solid CaCO3 (calcite), or Ca(Mg)CO3 (dolomite).

I've skipped over a few things, but that's it in a nutshell.

What we want as growers is to get Ca and Mg to our plants. I imagine these supplements are slightly, maybe substantially, acidified to keep the ions freely available until you use them. The acid buffers inherent in soil, or the hydro operator will keep the pH in a range that keeps enough of the Ca and Mg ions free. Only at pH's beyond 8.0 would you have to worry about your added Ca or Mg locking up with something and not getting to your plants.

Thanks Kriegs for the answer.

 

[wyteboi]

Like I quoted before, the fertilizer and water quality (profile) must complement each other. If you use tap water and soil, then you can get by with something like Peters which has about 8 elements and no Ca. If you use RO water and basic water culture, then you need something like Dyna-Gro that supplies 16 elements, in sufficient quantities to where they'll do the plant some good.

So what would your opinion be on ro water, soil and peters? Would i want to go with something like dyna-gro to get back what i lost during ro? I mean of course i will know all this before long because my babies will tell me but i love learning , i like opinions but i love the facts you guys provide.
Again thanks UB, dave , kriegs and the other advanced folks on here!

wb

 

[Uncle Ben]

So what would your opinion be on ro water, soil and peters? Would i want to go with something like dyna-gro to get back what i lost during ro? I mean of course i will know all this before long because my babies will tell me but i love learning , i like opinions but i love the facts you guys provide.
Again thanks UB, dave , kriegs and the other advanced folks on here!

wb

Why bother with RO water when tap water is fine for soil?

This link explains the relationships better than I can or ever will be able to. http://www.staugorchidsociety.org/PDF/IPAWaterQuality.pdf

 

[wyteboi]

Why bother with RO water when tap water is fine for soil?

This link explains the relationships better than I can or ever will be able to. http://www.staugorchidsociety.org/PDF/IPAWaterQuality.pdf

Thanks for the link.
I have always used tap, its just when i got lost in the labels , i changed everything, then you got me back on track , but i still own a ro , so i might as well use it till the filters need replaced.
My main concern (in the last few months) is the really strong bleach smell my tap has........i been fuckin with fish and plants for years and a loud clorine smell is fine but this bleach shit aint right. its so strong after running bath water that it smells like the chemical room for public swimming pools.
Dont taste that bad though

 

[Kriegs]

Thanks for the link.
I have always used tap, its just when i got lost in the labels , i changed everything, then you got me back on track , but i still own a ro , so i might as well use it till the filters need replaced.
My main concern (in the last few months) is the really strong bleach smell my tap has........i been fuckin with fish and plants for years and a loud clorine smell is fine but this bleach shit aint right. its so strong after running bath water that it smells like the chemical room for public swimming pools.
Dont taste that bad though

That's raw chorine for sure. This may be a case where you want to leave your MJ water out overnight, but I wonder if even that old bromide is legit.

A lot of municipal systems temporarily go back to treating with raw chlorine gas for times of year when contamination risks are higher. The US has had a really wet winter this year, so your supplier probably added this extra step to remove pathogens. They'll likely quit that when rainfall / snowmelt backs off.

Anyway, it's gaseous chlorine that produces the smell. Choramine, a product of systems that treat by using a combination of lime, chlorine, and ammonia, does not smell and does not de-gas when water is left standing overnight.

Chloramines have never been shown to have an adverse affect on any plants. They do exert an extremely fleeting suppression on soil flora, but they repopulate right back - within hours. And it's a partial kill, not total.

Bottom line -- municipal tap water is fine for growing. The quality of most tap water probably, but doesn't always, improves by standing out overnight.

 

[Kriegs]

Hey, UB and crew..

I have seen folks purport that the yellowing of the cotyledons on a MJ plant is a cue to start feeding. Seems to me, those cotyledons are doomed to drop anyways, and "feed me" is not necessarily what the plant means by that.

On the other hand, while they're there, perhaps that's a useful cue they provide? I can't say that I've ever watched the "shrivel and drop" process closely enough to have an inkling on it either way.


What say you?

 

[Uncle Ben]

Hey, UB and crew..

I have seen folks purport that the yellowing of the cotyledons on a MJ plant is a cue to start feeding.

Sounds like alot of purportin' to me.

Forum rule of thumb - if it's been said in a forum and repeated, then it must be true.

 

[blahblahblah123]

Hey, UB and crew..

I have seen folks purport that the yellowing of the cotyledons on a MJ plant is a cue to start feeding.

Honestly I think your behind if your just now giving the plant nutes when the cotyledons die..

 

[riddleme]

Honestly I think your behind if your just now giving the plant nutes when the cotyledons die..

Joking, right?

 

[Kriegs]

Joking, right?

No doubt...

blahblahblah?

bwah-hah-hah-hah!


Just razzin' ya, bro... love your avatar, though.

There's no way I'm behind on anything, dude, with these gals. They're beau-yoo-tiful and packing it on everyday. The whole-plant pic is 2 weeks seed from soil; 12/12 out of the gate.

 

[Kriegs]

Some dyna-gro goodies I picked up on my lunch hour -- got FoliagePro for veg and stretch; Liquid Grow for post-stretch flowering. Been reading up on and comparing stuff all over, and I'm stoked about these products -- thanks UB.

The 12/12 superskunks got a 1/2-dose of the FP today.

 

[Uncle Ben]

Some dyna-gro goodies I picked up on my lunch hour -- got FoliagePro for veg and stretch; Liquid Grow for post-stretch flowering. Been reading up on and comparing stuff all over, and I'm stoked about these products -- thanks UB.

The 12/12 superskunks got a 1/2-dose of the FP today.

I'd say you're good to go. The rest is up to you regarding balancing plant nutrition along with light, temps, water quality, etc. Don't be afraid to call the tech guys up. They work with the professional folks so you'll get a straight answer.

Have fun,
UB