Humic Acid effect on palm trees?

[PalmX]

The fertilizer I like to use on my other plants offers a product for healthier roots that contains Humic Acid in it.

I do use it on my Aroids and Philodendrons with great success, but was curious if anyone has experience any possible side effects when using it on palms? Specifically with palms that are potted. 

[sonoranfans]

I have been using a 17% humic fulvic acid plus kelp product on my yard, palms and plants, for 14 years.  https://www.natureslawn.com/product/natures-magic/   I have used dried humic acid powder and mixed it in water to deliver but the dried form lacks the fulvates/fulvic acids as they are only stable in a liquid.  There is literature out there, I haven't seen a test with genetic controls(use clones) but again not much is funded that isn't patentable. That said, I have used humic acid 2x a year typically and I always plant my new palms with a good dousing, but no fertilizer.  Humic acid suppresses harmful nematodes which is a problem in sandy florida.   Overall I have had good growth with my overall gardening practices and the humic acid treatment is something I will always do in sandy soil.  We have a real wet season so I put it down 6-8 weeks before the wet season comes.  Flooding rains will rinse it away so consider its better to apply it a few weeks before the hot/wet season.  The final decomposition products of mulch are Humic acid and fulvic acid and their salts(fulvates).  This way you are not adding anything to the soil that you don't -eventually- get from mulching, just more concentrated than you will ever get from mulch and its delivered immediately.  I dilute the 17% humic  in a sprayer or 1/2 cup per 5 gallons water in a watering can.  Humic has many soil functions including chelating and rinsing away excess salts and metals.

On potted palms its a must and perhaps 3x a year to rinse out excess fertilizer salts which tend to accumulate even faster in pots than in soil during the dry season.

[Phoenikakias]

Unless you use a very light medium and water the heck out of the plant. I use this method on malagasian palms, which would otherwise not survive in my summer hot conditions. When I mean light however I mean really light ingredients such as leca, pumice, seramis, pine bark, lava. I use only slow release fertilizer not under 6 months and plants up to now never displayed any nutritional def. Whether they will ever become root bound is questionable, but I am happy seeing them survive grow larger.

[Than]

Is it of any use to apply humic + fulvic acid fertilizer at this time of the year?

[Phoenikakias]

Never too late!

[Johnny Palmseed]

3 hours ago, Than said:

Is it of any use to apply humic + fulvic acid fertilizer at this time of the year?

As stated by @Phoenikakias above, it’s never too late. You can apply this whenever it is convenient. It is a supplement and not a fertilizer so the timing is not critical. And as stated by @sonoranfans, if you are approaching a rainy season, you should apply it early enough for it to be absorbed as opposed to washed out. Otherwise, just wait until after the rains.

[Than]

I bought a 1lt bottle of humic+fulvic acid today (humic 4.5% w/v and fulvic 15.5% w/v). It says that if applied as foliar spray the dosage is 100-300 ml per 100 lt of water "in repeated applications". If used in root watering then dosage is 1.5 lt per 1000 sq.m.

I am a bit lost (I was sh!t in maths at school). How much should I use to root water an individual young Syagrus or a Ravenala? Or should I use it as a foliar spray? In that case what exactly does repeated applications mean? Once every how often? 

[Johnny Palmseed]

@Than I would use this product on the roots. The rate of 100 - 300 ml per 100 lt is easy to change to 1 -3 ml product per 1 lt water. That is a very light dosing rate which makes sense for foliar applications. Using it on the roots would not need to be diluted as much. The 1.5 lt per 1000 sq m correlates to about 660 sq m in a single 1 Lt bottle. You would mix in whatever amount of water is appropriate to get the product applied. You would not need to follow the above ratio since the water is just added to the product to get the job done. When I mix mine, it is specified at 2-3 ounces per gallon which equates to 2 per 128 or 3 per 128. This is for 100 sq ft so about 10 x 10 or about 9-10 sq m. 1000 sq m is a square measuring 31 m X 31 m. If you have a palm root area that is circular, use the π r² formula to get the area. Or just ask Siri.

[Than]

7 hours ago, Johnny Palmseed said:

You would not need to follow the above ratio since the water is just added to the product to get the job done

Aha, this is good to know! Thanks a lot.

I did ask chatGPT to do the maths for me but it came up with some random numbers and explained that if I followed the ratio written on the bottle it would be too small an amount..