Sourcing and providing the right feed and fertilizer for your bonsai tree is essential.
But many people who care for these precious trees wonder what fertilizer is best.
The best fertilizer for a bonsai depends on the season, the environment (indoor/outdoor) and whether you want the tree to flower or not.
In general, however, you should use a fertilizer that is high in nitrogen in the Nitrogen-Phosphorus-Potassium (NPK) ratio.
However, some bonsai, such as flowering species, may require different ratios, e.g. B. those with more phosphorus.
Read on as I unpack the best NPK fertilizer ratios for different bonsai tree growth scenarios.
I will also give some recommendations for fertilizers.
Best fertilizers for outdoor bonsai trees
When looking for the right type of fertilizer, you need to consider the time of year and the weather when you arelet the tree grow outside.
While some growers choose to use a balanced ratio of nitrogen, phosphorus, and potassium throughout the season, it may be best to use a fertilizer with a low nitrogen ratio when the weather turns colder.
So as the year progresses you can start reducing the amount of nitrogen in your fertilizer mix.
In fact, some growers even forego nitrogen altogether during the winter season so their bonsai trees don't have to waste energy growing when they are dormant.
Overall, however, you should follow these general fertilizer ratios (or a similar ratio) based on the time of year you're experiencing:
- Spring - NPK 10-6-6
- Summer – NPK 6-6-6
- Autumn - NPK 3-6-6
- Winter – NPK 0-10-10
Best fertilizers for outdoor bonsai trees
Below are some of my recommendations for the best fertilizers for outdoor bonsai trees, from spring to winter mixes.
Spring - The Grow Co Slow Release Bonsai Food Pellets
This bonsai tree fertilizer is ideal for outdoor trees experiencing spring weather.
You can use this fertilizer for bonsai varieties including ficus, juniper, schefflera, jade, ginseng, money tree, bamboo and other dwarf tree varieties.
Summer - The Grow Co Liquid Organic Bonsai Food
For the summer, I recommend a gentle and balanced fertilizer mix for outdoor bonsai trees.
The Grow Co Organic Bonsai Food has a balanced NPK of 1-1-1 that will not burn or damage tree roots.
Fall - Dyna-Gro Bonsai Liquid Food
For the fall season, when the weather gets cooler, I recommend trying a mix with a lower nitrogen content, such as B. Dyna-Gro.
It has an NPK ratio of 7-9-5, which you can dilute to your desired concentration before use.
Winter – New England Bonsai Gardens Herbst; Winterdünger
I recommend a nitrogen-free fertilizer for outdoor bonsai trees during the winter months, like this New England Bonsai Gardens Fall Winter Fertilizer.
This food has a NPK ratio of 0-10-10 and supports root health.
It also protects bonsai trees from penetrating winter weather.
Best Fertilizers for Indoor Bonsai Trees
Indoor bonsai trees, on the other hand, will not withstand the changing weather, so the time of year is not that important when choosing a fertilizer.
In most cases, your home will generally maintain the same temperature and humidity year-round, although access to natural light can change throughout the year.
Because of these conditions, you should find a liquid fertilizer with a more balanced NPK ratio (6-6-6 or 1-1-1) for indoor trees.
And you won't change that ratio too often since thenindoor bonsai treeswill grow all year.
The main exception is when you are facing specific problems like root damage or a lack of buds that require a specific nutrient ratio to be fixed.
Overall, remember that indoor bonsai fertilizer should definitely have some nitrogen content, but not so much that it overwhelms the plant.
You should also consider the type of bonsai plant you have.
It's more common to grow tropical and subtropical bonsai varieties indoors as they thrive better in this environment, so you'll likely need a fertilizer suitable for these trees.
Best Fertilizers for Indoor Bonsai Trees
Below are some of my top fertilizer tips for bonsai plants growing indoors.
I have selected a liquid fertilizer as well as a pellet/granular fertilizer to give you options for different preferences.
Uncle Bill's Bonsai Brew
I recommend this product as the manufacturer makes it specifically for indoor bonsai trees.
It is a balanced NPK (3-3-3) formula in a water soluble liquid blend that is easy to apply to indoor bonsai.
Superfly Bonsai Slow Release Fertilizer Pellets
This bonsai fertilizer is not a liquid fertiliser, but it has a fairly balanced mix of NPK (5-7-4).
The nutrients release over a period of 1-2 months to support indoor bonsai tree growth, including root, leaf and flower development.
Best fertilizers for flowering bonsai trees
If you want your bonsai tree to start flowering, you need a fertilizer with a unique nutrient ratio.
In this case, your fertilizer should not be as balanced, but should have a higher phosphorus content in the NPK ratio.
You need more phosphorus because it is the nutrient that supports fruit and flower growth in most plants.
You can try a fertilizer with a ratio of 6-10-6, 3-12-6, 7-9-5 or a similar ratio as phosphorus helps bonsai trees to form healthy roots and flowers.
A lack of phosphorus for a bonsai tree can lead to stunted growth, at which point it has trouble flowering.
Best fertilizers for flowering bonsai trees
I have a few fertilizer recommendations if you want to get your bonsai tree to bloom.
Note, however, that you may still need to change the nutrient ratio of your fertilizer slightly depending on your growing environment (indoor/outdoor or time of year).
Dyna-Gro Bloom
Dyna-Gro Bloom liquid plant fertilizer is an incredibly effective bonsai fertilizer when you want to encourage flowering.
It has an NPK ratio of 3-12-6 (quite high in phosphorus) to encourage more vibrant, healthier buds.
And since it's a liquid fertilizer, you can dilute it as much as you want or need before applying.
Dyna-Gro Liquid Grow
Dyna-Gro Liquid Grow is another valid option if you want to get your bonsai to bloom.
It's a less intense concentration of phosphorus that still provides enough nutrients to support flowering.
It uses an NPK ratio of 7-9-5 so your bonsai tree still gets enough nitrogen and potassium to support the roots and leaves.
Best fertilizers for beginner bonsai tree growers
When it comes to bonsai beginners, choosing a fertilizer may seem difficult.
But that doesn't have to be the case.
When you are just starting out you should generally stick to a balanced NPK ratio (i.e. 6-6-6) as your main focus at this point is to keep the bonsai tree healthy and vibrant.
Experts recommend moving on to varying NPK fertilizer ratios once you've nurtured the tree with a balanced mix.
Dyna-Gro mixes are always a pretty failsafe fertilizer option if you want to try your hand at bonsai tree care.
Which bonsai tree fertilizer is the best - liquid or granulated?
Another factor that can affect which fertilizer is best for growing bonsai is the type of fertilizer.
There are many fertilizers on the market, but you'll mostly find them in liquid feed or pellet/granular feed.
I tend to find that granular fertilizers are the best option whether you are an experienced bonsai grower or a beginner.
However, you should look at the pros and cons of each fertilizer category below to see for yourself.
Granulatdünger
One thing to remember about granular fertilizers is that you simply sprinkle them on the soil of your bonsai tree.
You don't have to add water right away or mix water with the granules before applying.
Also, granular/pellet fertilizers are slow-release, meaning they will dissolve into your soil over time (about a month or two).
This gradual release is gentle on the soil and the bonsai tree, so most people recommend using this type of fertilizer.
It also has the benefit of being visible to the eye, so you can tell when it's fully dissolving and leaking.
liquid fertilizer
On the downside, liquid fertilizers are somewhat inconvenient to use, and beginners might struggle to find success with them.
Because liquid fertilizers aren't slow-release, they're very concentrated, which means you'll need to dilute them.
Therefore, you need to mix them with water and then apply the mixture to your bonsai tree soil.
In a way, they are beneficial because they provide nutrients to your tree quickly.
However, they don't last as long and can spread unevenly due to the way bonsai soil tends to drain.
Final Thoughts
Many bonsai growers face a similar problem either early in their growth journey or even after years of practice.
People want to know the best fertilizer for bonsai trees, which is why I created this guide.
Overall, bonsai trees require a combination of nitrogen, phosphorus, and potassium (NPK) in fertilizer to support their roots, leaves, and flowers.
In general, bonsai trees should have a balanced NPK ratio for optimal growth.
But depending on the season and growing conditions, you may need a different fertilizer ratio to properly support the plant.
So think about all your decisions when choosing the best fertilizer for your bonsai tree.
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