Japanese Maple newbie

[Saz34]

Hi! I was recently gifted a Japanese maple, it’s 5 years old according to the label and it’s beautiful. I want to do the best by it and keep it healthy but I need some help with fertiliser. I can’t seem to find a straight answer on google in terms of what to use.

Is it good to use Osmocote Trees, Shrubs & Citrus at the beginning of spring / autumn and seasol as a top up every fortnight? If not can someone recommend me what to use? I’m very confused with all the high / low nitrogen / phos etc.

Thanks

[Alex_B]

Hi Saz,

I tend to use a mixture of powerfeed liquid fertilizer and seasol every fortnight during the growing season. The powerfeed is the fertilizer while the seasol, to my understanding, is sort of like a tonic for roots so its not a fertilizer but I combine the two in the same watering can. You can use osmocote but as I understand people only tend to use that once they report a plant so it get mixed in with the soil but this should not be your primary fertilizer as bonsai tend to get all the nutrients out of the soil fairly quickly.

During winter I will be using charlie carp liquid fertilizer as it is a bit more balanced but I could probably just get away with continuing to use the powerfeed its just that I bought both and don't want to waste one haha. In winter you should fertilize about once a month to my understanding (I'm still very new to bonsai) as most plants become dormant during the winter so they don't need the nutrients as much.

Hope this helps and welcome to the world of bonsai.

[shibui]

Don't get caught up in overthinking fertilizer.
There will always be someone who thinks they know a lot but often the opinions are hot air.
Plants need a certain amount of each nutrient. Most fetilisers are formulated to have that mix the plants require so you can use any plant fertilizer and your tree will be fine.
Osmocote and similar controolled release ferts slowly release a mix of nutrients aver a long period. Those are great for those of us who are busy or forget to fertilize regularly. They work best when buried in the soil so most of us add it when repotting and maybe drill some more into holes in the soil each year when the tree won't be repotted. Controlled release gives a constant background nutrient availability.

Liquid fert is easy to apply, quick acting and leaves no mess. Many growers use a liquid fertilizer every few weeks while the tree is growing to give a boost to the trees.
Note that powerfeed has seasol as part of the mix. I can't see what good adding more seasol will do.
Also note that seasol is not sold as a fertilizer. It has very variable rates of nutrients depending on the time of year and the source of the seaweed. That's why it is sold as a soil conditioner, not a fertilizer. Many people use it as a supplement buy you should not rely on it as the basis of your fertilizing schedule.
Many bonsai growers use organic, solid fertilizer on their trees. There are lots of home mixtures and a few commercial ones available. Organic solids release the nutrients as they slowly decay over weeks or months. Organic ferts may have a variable amount of nutrients so may not always supply everything the trees need. It can also look unsightly sitting on the surface slowly decomposing.

There is no point fertilizing trees that are dormant as they don't take up nutrients. No leaves = no fertilizer however many evergreen trees are still slightly active in our winters so some fert can be good for them.

Higher N fert are generally used to promote strong, vigorous growth. Used when trees are still growing, thickening and developing branching. High N fert may promote vigorous growth with long internodes that can make it difficult to develop good ramification in developing bonsai.
Low N and higher K is used to promote flowering. Not required for trees that are still growing and developing.
High K is sometimes recommended to increase winter hardiness. That is only needed in very cold climates so we don't need to worry anywhere in Australia.
balanced is a confusing word. In fertilizer balance does not mean equal as in 10.10.10. Balance means the correct amount of each nutrient as trees require them. To add even more confusion fert is measured differently in Australia where we measure the elemental parts of the fertilizer. In Britain and USA they measure the total amount of the compounds that are included so 10.10.10 in USA is the same as 10. 4.4. 8.3 here in Australia.

All that can be quite confusing so as I started out with, don't overthink it. Fertilizer companies know what they are doing. They make fertilizer that is mixed to have all the nutrients in the correct balance for most plants. Just get a fertilizer and use it according to directions and your plants will be fine.

[treeman]

I would not recommend using osmocote on Japanese maples if they are developed. It contains too much nitrogen and leads to big leaves and course growth which is the last thing you want. Organics would be better. It takes very little to keep Japanese maples happy.