VF-11 and other cool fertilizer tricks on palms

[Mauna Kea Cloudforest]

Problem statement: during the Winter, ammonium nitrate stops being metabolized by bacteria when the soil temperature drops. This is why many grower greenhouses reek of ammonium during the colder Winter months. Obviously it's challenging to keep palms happy if they are used to warmer soil temperatures to feed. To me, there are two very specific solutions: 1) calcium nitrate, and 2) foliar sprays.

Let me start with 1) and it get it out of the way. Yes, calcium nitrate is more readily assimilated by bacteria at lower temperatures, hence plants will keep on growing much better with lower soil temps if fed with calcium nitrate during the Winter. Palms are way hardier if properly fed in the Winter unless you can somehow keep the soil dry so that they go dormant. I have no such luck here given we get 50-100 inches of rain between November and April. So calcium nitrate is a great way to keep sugar levels elevated in the foliage and thus drop the freezing point a couple of degrees. FYI, you cannot get calcium nitrate unless you get it wholesale at commercial suppliers. It's only available to farmers and orchardists.

So now let me get to the more dubious topic of foliar sprays. I don't have much experience with these on palms, and I've stopped to foliar spray years ago after reading all the science which suggest that foliar feeding isn't effective. But that can't be all correct, as one common practice in apple orchards is to spray nitrate directly on the leaves 6 weeks before harvest. In addition, calcium sprays are also common do address bitter pit in apples. So there most definitely is something to foliar sprays.

Has anyone played around with foliar sprays, in particular VF-11 and Kelp sprays? The only issue I see is with waxy palms such as bizmarck and braheas. The water just beads off and nothing is absorbed. Removing the wax is an option, but not a good one as it compromises the palm's ability to fight heat, drought and cold.

VF-11 is interesting but it's a bit of a scam due to the high dilution level of the product. See https://sharepoint.cahnrs.wsu.edu/blogs/urbanhort/archive/2010/06/10/here%E2%80%99s-the-plant-food-everyone-is-talking-about.aspx. VF-11 is a bit of a rip off because it's essentially potassium nitrate and potassium phosphate in a highly diluted form. You can make your own using stomp decomposition accelerators, which are nothing more than concentrated potassium nitrate. At the dilution levels in VF-11, a small jar of stump decomposition accelerator would make enough VF-11 that you could open up your own store.

But the idea of nutrient delivery over foliar sprays is sound. Kelp spray is perhaps the best way. I plan on experimenting a bit with foliar sprays and I am really curious to hear what others have done.

[sonoranfans]

on the calcium nitrate, too much calcium in your soil inhibits magnesium uptake, and we know how important Mg is to photo synthesis. This is trickier than it sounds I expect. On the foliar sprays, there are lots of marketing claims, and many horticulturalists dispute the claimed degree of impact. I would like to see an intdependently reviewed article, not just claims.

[Mauna Kea Cloudforest]

on the calcium nitrate, too much calcium in your soil inhibits magnesium uptake, and we know how important Mg is to photo synthesis. This is trickier than it sounds I expect. On the foliar sprays, there are lots of marketing claims, and many horticulturalists dispute the claimed degree of impact. I would like to see an intdependently reviewed article, not just claims.

Wouldn't you just add epsom salts to compensate by feeding on calcium nitrate? I actually got the Calcium Nitrate formula from a wholesale nursery friend of mine, this is what they do during the Winter months and it works well. On my avocados the calcium also inhibits fungal growth and makes roots less susceptible to root rot.

[sonoranfans]

on the calcium nitrate, too much calcium in your soil inhibits magnesium uptake, and we know how important Mg is to photo synthesis. This is trickier than it sounds I expect. On the foliar sprays, there are lots of marketing claims, and many horticulturalists dispute the claimed degree of impact. I would like to see an intdependently reviewed article, not just claims.

Wouldn't you just add epsom salts to compensate by feeding on calcium nitrate? I actually got the Calcium Nitrate formula from a wholesale nursery friend of mine, this is what they do during the Winter months and it works well. On my avocados the calcium also inhibits fungal growth and makes roots less susceptible to root rot.

yes you get into the position of balancing the Ca/Mg ratio, which is done in most palm ferts. In this case you will need to ensure that it is balanced in the soil...

[George Sparkman]

Hi Axel,

are you sure your rainfall total is correct ?

It seems really low. That's almost like Indio,CA.

Annual rainfall: 115mm between Nov-April, bone dry the rest of the year

[Mauna Kea Cloudforest]

Hi Axel,

are you sure your rainfall total is correct ?

It seems really low. That's almost like Indio,CA.

Annual rainfall: 115mm between Nov-April, bone dry the rest of the year

Deuh! cm, not mm. Thanks for catching that. About 50 inches.

[Jastin]

Axel,

Is this what you need? http://www.amazon.com/Atlantis-Hydroponics-Calcium-Nitrate/dp/B0013LQJKU

[George Sparkman]

The number just did not fit with what you were telling me about your place when you were here a few weeks ago.

From what I have been reading in your posts you seem to be going full throttle with your garden !

[Mauna Kea Cloudforest]

Axel,

Is this what you need? http://www.amazon.com/Atlantis-Hydroponics-Calcium-Nitrate/dp/B0013LQJKU

Dang! Yup, this is it. You can find just about everything on Amazon. Free shipping too. A little pricey compared to $30/50lbs from our local commercial Ag supplier. $1.4/lbs versus 60 cents/lbs.

The number just did not fit with what you were telling me about your place when you were here a few weeks ago.

From what I have been reading in your posts you seem to be going full throttle with your garden !

Yes, it's an annual Spring ritual. About 30 palms went into the ground, including all the ones you sold me. The mad foxes do seem happy in the cool nights as you suggested. Still planning on hauling in a 36" boxed bismarckia and a large kentia, so not quite done yet. I have to first remove a papaya that's got a 1.5 feet diameter trunk, and a giant capulin cherry that's now over 30 feet tall. Papayas look pretty when smaller, but once they get real big they get out of hand. The capulin cherry is now host to the dreaded Japanese fruit fly, so it's got to go.