Slow release fertilizers

[August44]

I would like to use a slow release fertilizer the year so I don't have the problem of forgetting to fertilize. I know there are many different kinds and different mixtures out there. I will be using it on maples and conifers and buying two different types is ok with me. Suggestions and advice welcome. Thanks for help, Peter

 

[WNC Bonsai]

I fell into that mindset last year too and immediately ran into more problems. The problem with slow release is it usually is temperature based and different formulations release at diffreent rates. So you need to know when to apply, the release rate factor and what controls it, how long it will last (and that varies with the past factor). I initially put on some Osmocote but then things got so complicated due to a cool wet spring/summer that I finally just pulled it all off and started using MiracleGro. In the end that was easier than trying to juggle all the variables with using slow relase and/or organics.

Now on top of the fertilizer what do you plan to do to proactively treat for fungal and insect attacks? So to add that to your application program. It’s like growing apples, if you want those big shiny red unblemished orbs you have to fertilize and treat for all kinds of potential problems in advance—bonsai are no different of you like nice leaves.

 

[Wires_Guy_wires]

If you water every day, and you will at some point, then it's pretty hard to forget fertilizing.
Slow release is relative; hit those pellets with water and sunlight, and they might just be very quick to release. Or it might be so slow, that it releases next winter.
And then what? I wouldn't know. I avoid those situations.
One fertilisation every 4-6 weeks, that's every 15th of the month. Set a notification in your phone calendar and nothing can go wrong. It's not a bad thing to skip a few times as well. It's worse to over do it, or to have little control over the actual release.

 

[Orion_metalhead]

Nigel Saunders fertilizes by adding a tiny amount of soluble fertilizer to his water when he waters through growing season. Has anyone else experimented with this? Viable or not?

I was thinking of using slow release also this summer... 7-7-7 or something along those lines. Thoughts?

 

[August44]

Ok, I understand with the slow release fertilizer. What is the best liquid fertilizer to use, amt per gallon and times to do it (Number of days between fertilizing). I have heard that MG works well....the one with the Azaleas on the box?? Thanks. Peter

 

[WNC Bonsai]

Nigel Saunders fertilizes by adding a tiny amount of soluble fertilizer to his water when he waters through growing season. Has anyone else experimented with this? Viable or not?

I was thinking of using slow release also this summer... 7-7-7 or something along those lines. Thoughts?

That’s how MiracleGro is applied. There are tons of different fertilizer solutions and granules that can be dissolved in your watering can. There are also hose end applicators and injectors that add it automatically to your hose. Pick your poison and your method. I usually just use a watering can and apply a good even amount to each plant instead of applying it through my hose. When it comes time for the monthly feed I just water with the fertilizer mix in a watering can instead of using the hose.

 

[WNC Bonsai]

Ok, this is where it gets complicated. Like all things bonsai there are lots of little rules with the type of fertilizer to use, when to use it, etc. For example no fert until 4-6 weeks after repotting. No fert on most confiers until they have hardened off. Keep your N content low on trees in refinement to keep internodes short. This is where research on your idividual species comes into play, so what kinds of trees do you have and what stages are they in? BTW the individual species guides at Bonsai4me.com are very helpful.

 

[August44]

I am dealing with pines, spruce, larch, and Maples. None of them are finish bonsai even though a few are in bonsai pots. Let me make sure I understand what you are saying Cofga, if I repot, even if I don't trim much off the roots, no fertilizer for 4-6 weeks? No fertilizer on conifers until they have hardened off?...what does "hardened off" mean? Thanks, Peter

 

[WNC Bonsai]

Interestingly I was watching one of Ryan Neil’s videos on YouTube yesterday where he addressed these questions and yes he said 4-6 weeks. His answer was you have to allow the tree to get its water and oxygen balance established before adding fertilizer to the mix. Let the roots grow and reestablish then the tree will be in a better position for growth and feeding. Now some folks have said posh, feed away right after repotting.

The idea with not feeding confiers that are flushing growth in the spring is they send out those new flushes of growth and if you dump on N then they will extend and grow a lot. Now if that is what you need in a young tree and don’t mind some long internodes then use that to your advantage. However if you are seeking short internodes then mange the growth by controlling N concentration.

Once the new growth hardens off it will not start expanding again so you can apply the N. Hardening off in this case occurs when the cutilces have completely formed on the new growth. This is seen in the change from light green to darker green and the shiny surface that is the cuticle.

The video I Refer to was BSOP Series: Spring Fundamentals. There are now dozens of his free videos on his Mirai channel on YouTube and the BSOP series is well worth the time to watch (BSOP=Bonsai Society of Portland). He takes you through the whole year going over what is going on in the trees etc.

 

[0soyoung]

There are lots of choices and one should use the fert system that works for them.

I use Osmocote-Plus (15-9-12, includes minors) and apply it at the rate of one-quarter to one-half teaspoon per pot gallon of substrate, once or twice a year. The release of the contents of the prills is temperature dependent. More fert is released the higher the temperature. Plants use more fert the higher the temperature. Maybe I am naive, but I do believe that the prill cover film has been engineered and tested to indeed release fert at rates to match general plant needs to a good approximation.

I use Turface MVP for my substrate. It has a CEC of about 35, Generally, I only apply new doses to fir, spruce, and most of my pines about the time of or after the summer solstice, which is when the new growth has pretty much hardened and, buds are being set for the next season. Good nitrogen nutrition is essential for budding.


btw, a 'pot gallon' is the amount of substrate that fills a standard black plastic 'one-gallon' nursery pot, which is actually something like only 80% of a US gallon, but is a quantity that is easy for me to eye-ball with all the various sized containers that I have trees growing in.

Also, I do have mushrooms in many pots in the fall - too much P discourages mico.

 

[Wires_Guy_wires]

Interestingly I was watching one of Ryan Neil’s videos on YouTube yesterday where he addressed these questions and yes he said 4-6 weeks. His answer was you have to allow the tree to get its water and oxygen balance established before adding fertilizer to the mix. Let the roots grow and reestablish then the tree will be in a better position for growth and feeding. Now some folks have said posh, feed away right after repotting.

I'm from that school of thoughts. I can explain this in human language: we break off parts but we don't provide the means to rebuild them, and we expect the tree to rebuild them anyways.
So, there's this carpenter dude, we drive a truck through his shed and tell him to fix it or he dies (in the case of plants this is quite literal). But we don't give him wood or nails to do so. Now he's going to have to invest his own resources instead. That's risky. We don't know if he has that kind of money. We assume he does, because he looks healthy. But can we know for sure?
Most plant structures can be built from carbon and water, but not all of them and not that well if there's nothing to support that growth.
In the lab, we put cuttings on full strength nutrients right away. They keep growing as usual, even without roots. They acquire the energy and supplements to start building, and away they go! Rooting stronger than ever!
When they're placed on empty medium, they do root faster but all growth after that is weaker than ever before. Then, when those fine and sensitive roots finally start taking hold, all adjusted to low levels of nutrients and fighting for survival, we slap them with fertilizer. That's risky in my opinion.

A light supplemental feed can be is beneficial to recovery. Maybe 1/4th of regular dose, or even lower. But absolutely no nutrients is not something I'd advise. Now bonsai might not be a field I've been in for long, but I've studied rooting behavior of (micro)cuttings and established plants for a looooong time. We want them back to health ASAP, not struggling to survive for 5 months. Those are usually the hottest months.
When looking at literature about, for example, black pines.. We see that cuttings are usually placed on full or half strength WP (woody plants) nutrients, and they perform pretty well. I'd suspect that if nutrient-devoid media would benefit the cuttings, somebody would have used it by now and would have written extensive papers about it that would mess up the current consensus. Don't get me wrong, I'd love to see that happen! But it didn't and it doesn't. That's why I think what I think.

Maybe plants have a way of making auxins without nitrogen, I don't know. But the indole acetic acid and indole butyric acid I do know about, all contain nitrogen. If nitrogen isn't supplied in the soil, the plant will take it from it's chlorophyll and other structures (that's why we see yellowing in plants that have pH issues and can't take up nitrogen, or in general nitrogen deficiencies). That's some interesting stuff to think about. I could be absolutely wrong about the benefits of nutrients, but I haven't found anything to counter those arguments myself. I'm counting on everyone else to try and do it for me.