Overuse of Kelp?

Good Morning


I have this organic garden bed … quite a lot of soil … that I suspect has been overdosed with Kelp. The type of kelp is Ascophyllum nodosum, useful as a pre-flowering spray to optimise flowering. Its analysis is: 17% organic potassium, with less than 2% Nitrogen, plus small amounts of Sulphur, Boron, Calcium. The bed grew uniform 4 meter Haze plants but growth stopped suddenly in the early stages of flowering.


Another person (who has left here in a hurry!) had access to the garden bed. During discussion with him about soil ingredients I disagreed that Kelp should be added to the soil in granular form. But I suspect he went ahead and applied Kelp in granular form to the soil because I had never previously seen such rampant early stage growth … and I ‘ve been growing for a very long … while at the same time these large plants flowered so poorly (see photo … lots of stem small flowers).


So, if I ‘m correct in my suspicions there would have been an excess of Potassium available to the plants which threw soil mineral balance totally out of whack. (The basalt soil garden bed had previously been amended with animal manures and rock potash as I have successfully done many times previously.)


I don’t understand why the plants seemed to stop flowering suddenly as if they just ran out of energy one morning. The harvested heads also dried out very quickly as if they had no density (altho they look and feel solid). There was very little smell and the heads were not sticky.


Am I on the right track? Are these symptoms consistent with over use of Kelp?


Can anyone explain this?


Thanks in advance … Cheers ...

Kelp is a complete food. Kelp will contain all of your B, C, A vitamins, Iodine, Calcium, Magnesium, All Omegas; and so much more . WATER SOLUBLE .. forms of nutrition ..

Flower structure looks to be a genetic disposition.

How new is the garden bed? What is the soil like under the new covering?

A lot of variables but overall Kelp seems to be the emergency support and not the harbinger of what ails you.

Those buds look good perhaps tad too much N for a narrow leaf.

Really hard to od with kelp. Narrow leaf likes weak n in flowering. Try a flush towards harvest to take n out of the plant. She'll be smoother smoke.

I add the shit out of granular kelp to my soil, and use it in teas. I use a little seaweed extract as well. Pretty much all through the plants life, but lighter at the end.
I dont know anything about your product your using, but my kelp meal is 1-.1-2 and seaweed extract is .1-0-.44. Its not strong stuff. Maybe your kelp product is more of a strong "concentrated" typa nute?
If it is a sativa type, maybe the previous amendments got to it? Manure n nld dont mix well? Grasping here.
As said above, a haze isnt gonna get you beefy solid buds.
Light cycle? Outdoors i assume? What kind of light hours are present? Anything over 12 hrs will surely stop flowering a haze.

When did you cut it? It doesn't look fresh to me.

Too much kelp has been documented to have many adverse effects such as reduced/stunted growth. I would be more concerned about your potassium levels though, which I seriously doubt you're getting just from kelp. What else did your test show? My guess is you're using too much of a high K compost that is causing other macro nutrients to be less available.

^^^ Yes.

I use the lower-rated kelp meal and have for years, though in days gone by, many years ago, I often also mixed my own Maxi-Crop from soluble powder, but it was the 1-.1-3 back then.

It's been my understanding for many years that while kelp can be a very good thing in proper dose, that the excesses of micro-nutes it carries, in the event of an O.D., can cause the sorts of stress that have otherwise stable female plants producing or more prone to male stress flowers that so many incorrectly refer to as 'hermies' that aren't true hermaphrodites at all.

In your case, however, the K number of your kelp is much higher. Whether your micro-nutes are equally elevated in that particular product or not, I can't say.

Just a few thoughts on my observations and past learning.

I'll add that over time, it seemed to me that of the varieties of kelp meal I (am using/have used), the K component has been coming down (from a 4, to a 3, & now to a 2), while I believe the salinity has come up a bit. I've only speculated on the 'why' of this.

Edit: referenced P when what I meant was K. Sorry for the confusion/error.

Teddybrae said:

Good Morning


I have this organic garden bed … quite a lot of soil … that I suspect has been overdosed with Kelp. The type of kelp is Ascophyllum nodosum, useful as a pre-flowering spray to optimise flowering. Its analysis is: 17% organic potassium, with less than 2% Nitrogen, plus small amounts of Sulphur, Boron, Calcium. The bed grew uniform 4 meter Haze plants but growth stopped suddenly in the early stages of flowering.


Another person (who has left here in a hurry!) had access to the garden bed. During discussion with him about soil ingredients I disagreed that Kelp should be added to the soil in granular form. But I suspect he went ahead and applied Kelp in granular form to the soil because I had never previously seen such rampant early stage growth … and I ‘ve been growing for a very long … while at the same time these large plants flowered so poorly (see photo … lots of stem small flowers).


So, if I ‘m correct in my suspicions there would have been an excess of Potassium available to the plants which threw soil mineral balance totally out of whack. (The basalt soil garden bed had previously been amended with animal manures and rock potash as I have successfully done many times previously.)


I don’t understand why the plants seemed to stop flowering suddenly as if they just ran out of energy one morning. The harvested heads also dried out very quickly as if they had no density (altho they look and feel solid). There was very little smell and the heads were not sticky.


Am I on the right track? Are these symptoms consistent with over use of Kelp?


Can anyone explain this?


Thanks in advance … Cheers ...


View Image

Click to expand...

G `day TB

Don`t blame the kelp .
Blame the guy who harvested a month too early . That`s a sativa dom bud . Needs 70 - 100 days ...

Thanks for sharin

EB .

Using cold-processed liquid seaweed from the maritimes. Just gave em the first feed of this particular product and did they ever blow up! Really makes everything about the plant bigger, i did notice quite a bit of stretch though.

Been using it for years, never had any issues that i know of.

thanks for the input so far Guys!

Elmer ... not too early. plants had stopped flowering ... stalled for some reason.

Moose Eater ... one possible consequence IF Kelp had been mixed into soil is K overdose because the soil had already been adequately amended with rock K.

Kis ... as above. rock potash only available relative to soil acidity. unlikely single source of overdose. no compost added. only mix animal manures into rich local basalt soil just like I 've done successfully many times before. regularly grow haze variety this years growth was unusually large so I suspect soil tampering.

thanks so far!

Note pls that there are three types of "Kelp" that I know of. I reiterate this is 17%K low nitrogen etc suitable foliar spray pre/during flowering.

Teddybrae said:

thanks for the input so far Guys!

Elmer ... not too early. plants had stopped flowering ... stalled for some reason.

Moose Eater ... one possible consequence IF Kelp had been mixed into soil is K overdose because the soil had already been adequately amended with rock K.

Kis ... as above. rock potash only available relative to soil acidity. unlikely single source of overdose. no compost added. only mix animal manures into rich local basalt soil just like I 've done successfully many times before. regularly grow haze variety this years growth was unusually large so I suspect soil tampering.

thanks so far!

Note pls that there are three types of "Kelp" that I know of. I reiterate this is 17%K low nitrogen etc suitable foliar spray pre/during flowering.

Click to expand...

I think it's important people distinguish between kelp meal and seaweed extract powder. Very different products. Seaweed extract powder is what's in Maxicrop and all the bottled nutrients. It's high in K because it's stabilized with potassium hydroxide.

Kelp meal is relatively low in NPK. K is only a few %.

A good read is TL Senn's book, Seaweed and Plant Growth. Different species of kelp will contain slightly different nutrient levels, enzymes, metabolites, etc....but in general most kelp meal is N. Atlantic Sea Kelp (ascophyllum nodosum).

Kelp is best used in small amounts at greater frequency based on with current research that I've seen. That means it's much better get your annual dosage in over multiple applications rather than all at once in the case of seaweed extract powder especially.

Hope that helps.

KIS, any idea as to why the particulate kelp meal I've seen and used over the last 25 years or so has slowly dropped in K, from a 4 to a 3 to a 2, and the salinity has increased? (*This has included at least 3 different sources/labels).

My best guesses were 1.) Over-harvesting lading to taking younger and younger kelp from the sea. 2.) Changes in washing/rinsing/processing taking out less salt, 3.) Changes in sub-species overall, or 4.) Who knows?

moose eater said:

KIS, any idea as to why the particulate kelp meal I've seen and used over the last 25 years or so has slowly dropped in K, from a 4 to a 3 to a 2, and the salinity has increased? (*This has included at least 3 different sources/labels).

My best guesses were 1.) Over-harvesting lading to taking younger and younger kelp from the sea. 2.) Changes in washing/rinsing/processing taking out less salt, 3.) Changes in sub-species overall, or 4.) Who knows?

Click to expand...

No clue, it could just be a labeling thing too. You're only required to list a minimum %, meaning it could be 5% K but only have 3% on the label.