Fertilizer injectors

I've been experiencing some nutrient deficiency issues in some of my trees, and am thinking that the problem may partly stem from under-fertilization. I typically apply a "dose" of liquid fertilizer every 7-10 days but in between I believe the 1-2x daily watering (in this very sunny, warm summer) may be leaching most of the fertilizers out of the pots. I would like to experiment with use of a more frequent, weaker fertilizer application. Not sure about those timed-release products (like osmocote), and don't really want "poo-balls" on all the plants. So this post is about the potential use of fertilizer injectors.

There was a thread earlier this year (see: Hose end Sprayers) about using hose-end sprayers for dispensing fertilizer. The consensus was that they are best avoided, and that concurs with what I've generally heard about them.

The other option is to use an injector that works upstream, allowing one to water and dispense a continuous stream of fertilizer. These types of systems are used by nurseries and can be very expensive. However, there are lower-priced options available - such as this one available through amazon. I'm wondering if anyone has used this or a similar product? If so, any experience to share?

Chances are a lower-end product like this won't be very accurate or precise in the amount of fertilizer dispensed. However, I don't think that's a big concern for the use I'm thinking of. I'd be starting out with a very weak fertilizer solution anyway - just want to have something in the water stream.

Any thoughts would be appreciated.

I use a time release product called Multicote, because it is balanced and has minors (trace elements)

coh wrote:The other option is to use an injector that works upstream, allowing one to water and dispense a continuous stream of fertilizer. These types of systems are used by nurseries and can be very expensive. However, there are lower-priced options available - such as this one available through amazon. I'm wondering if anyone has used this or a similar product? If so, any experience to share?

Chris, that's exactly what I'm using. A friend gave me a spare one he had, and it works fantastically. So much faster than using watering cans and fertilizing 2gal per can took a long time. I'm much better now at feeding every 7 dys now.

Billy M. Rhodes wrote:I use a time release product called Multicote, because it is balanced and has minors (trace elements)

Billy,

Thanks...I will look into this (and note that Jay is now testing a version of osmocote as well). How long have you been using this?

Fore wrote:
Chris, that's exactly what I'm using. A friend gave me a spare one he had, and it works fantastically. So much faster than using watering cans and fertilizing 2gal per can took a long time. I'm much better now at feeding every 7 dys now.

Chris,

Thanks...just to be clear, are you saying that you're using the exact one that I posted in the amazon link? Or some other type/brand of fertilizer injector?

coh wrote:

Billy M. Rhodes wrote:I use a time release product called Multicote, because it is balanced and has minors (trace elements)

Billy,

Thanks...I will look into this (and note that Jay is now testing a version of osmocote as well). How long have you been using this?

I have been using Osmocote/Multicote for at least 20 years.

Yes Chris, that EZ Flo off Amazon's site.

Thanks guys. Does anyone else who has used one of these (not necessarily the one that I linked) have anything to add?

One thing I'm noticing as I'm scanning the EZ Flo website specs is it seems its minimum dilution rate for the "SLOW" setting is 1-1000 with the hose bib feed ratio, that will be too strong fed daily with a product like Dyna-grow and I think it would be too strong with other chem ferts as well. They mention a dilution of 1-2,000 ratio available with the coupling connection but I can't find further specs about that kind of connection but thats a lot closer to what would be appropriate for fertilizing bonsai on a once a week basis. I wouldn't feed at those strengths with every feeding.

I find that my dilution of dyna is 1-3,000 (thats 1/4 tsp per gallon) once a week won't burn. so that gives you an idea of how weak concentrated ferts like that need to be in order not to burn and thats fed weekly. You would just have to get a system that would allow you to dial down into that sort of range. But if you want to feed daily I'm not sure what ratio you would need to be able to offer, maybe 1-20,000? I'm not sure about pre-diluting the mixture as it goes in the pressure bottle before hand to help achieve that sort of dilution.

Thats about all i can think of.
-Jay

Thanks for your thoughts, Jay. I will look at those specs more closely before deciding. I was figuring that I'd be starting with an already very diluted solution. Was not necessarily thinking about using the fertilizer with every watering, but definitely more frequently than I'm currently doing.

I'm currently using a considerably stronger solution than you every 7-10 days (about twice as strong) and have not noticed any burning, but I really don't have many of the susceptible tree species.

coh wrote:
I'm currently using a considerably stronger solution than you every 7-10 days (about twice as strong) and have not noticed any burning, but I really don't have many of the susceptible tree species.

Yeah, its been the real "light" feeders that have given me issues, the Maples, beeches etc. Things like the Rain tree or the apples etc..they can't get enough. The light feeders also have to have the Osmocote done very sparingly as well.

-Jay

Boy, I've really been dosing them up. Matt Ouwinga hooked me up with this and told me he figured out the dosing conversion long ago, but uses MGrow, 14oz, using the 3 or fast setting gave him 1:100ppm to give a dosage of 1 tbsp per gallon of injected water. Since I was already giving twice the amt. of MG before I got the injector, I used 28oz of MG using setting 3 now for about 2 mos now. I've had no leaf burn at all on any plants, cypress, PP, JBP, JM, Larch, Trident, Shimpaku and a couple of other deciduous trees. I did this after reading Walter Palls advice where he uses 5x the concentration that's recommended. Interesting Jay we're having different results.

Edit: When this heat wave hit us last week, I moved the JMs to 30% shade cloth, so maybe that's helping the trees tolerate the higher dosage. Walter said as long as you gradually incr. the strength, in well draining soil, it should tolerate it well.

Fore wrote:in well draining soil,

Thats the key.

i'm in pure Turface which holds 40% water by volume and thats just the particles themselves not counting the spaces between the particles. It holds on to a LOT of water (a bit too much IMO) and if that water is fertilizer with a high E.C. (i.e salts) it burns my roots or hyper accumulates in the plant tissues and I get toxicities. Either the plant can't absorb the fertilizer fast enough (burns the roots), or it absorbs to much over too long a period (burns the foliage.) I can't tolerate even a little blackening of a leaf tip and have seen a few folks blaming marginal leaf scorch and tip blackening on heat or desiccation, when in fact its a fertilizer burn.

I suppose if my trees were planted in pea gravel or something like that, I could fertilize them at 5x strength and they would be fine. As I remember Walter also follows his fertilizing with a strong flushing of the medium to REMOVE all that extra fertilizer he's feeding his trees. The grass under his benches must be wonderfully lush!

-Jay

ETA. I will be changing my soil recipe next year and including a percentage of granite grit (a la Julian Adams) and perhaps with less Turface in the mix I may be able to UP the ferts!! Always experimenting!!

Chris (Fore), what are you using as a soil mix?

LOL Jay, you're absolutely correct! I'm using Turface/Grit/Lava in about a 2:1:1 ratio.

I went ahead and purchased the EZ-FLO 3/4 Gallon Hose Bib Fertilizer Injector so I could tinker do some experiments. This should be considered a very preliminary review.

The unit was easy to set up. I'm not sure how well the connections and tubing will hold up over time, but so far (about 2 weeks) so good.

There is a dial adjustment on the top of the unit with 4 feed rates - from slow (2/3 tsp per gallon) to fast (2 tablespoons per gallon). So far I've only tested the "fast" setting. I mixed up a batch of fertilizer to a concentration (TDS) of about 1400 ppm and filled the plastic bottle. Set the dial to fast, and ran the water for a couple of minutes to let the system equilibrate. At that point I tested the water coming out of the hose (after fertilizer injection) and found about 13 ppm of TDS above what was present in the municipal water. This is pretty much what was expected - a gallon has 256 tablespoons, so 2 tbl/gallon = 2/256 = 1/128. Dividing the stock solution (1400 ppm) by 128 yields about 11 ppm.

I tested the water numerous times while watering and the results were consistent.

The solution in the bottle becomes diluted over time as fresh water is added during the siphoning process. As of today the bottle contains about 600 ppm of fertilizer, and the output water has about 4 - 5 ppm of fertilizer. Again, this is about what one would expect (600 / 128 = 4.7).

At some point I will be testing with higher fertilizer concentrations and also the slower injection rate, and will report on the results. If anyone else has experience with any of these units, please feel free to add your thoughts.