The best bonsai fertilizer is one you can apply little and often without burning shallow roots growing in a tiny volume of fast-draining soil. In practice that means either slow-release pellets that sit on the soil surface and feed a bit with every watering, or a liquid you dilute and use on a regular schedule. Organic cakes such as Biogold are the traditional choice for outdoor trees, higher-nitrogen pellets suit vigorous tropicals and developing trees, and mild liquids or foliar mists work well for indoor bonsai on a windowsill. We picked seven products that cover each style, with every detail taken from what the listing states.
Part of our Houseplants & Container Gardening guide →
In this guide
- 1. Biogold Original — Best Organic Pellet
- 2. Perfect Plants Bonsai Pellets — Best Set-and-Forget Feeding
- 3. SUPERthrive Bonsai-Pro — Best Liquid Concentrate
- 4. The Grow Co Bonsai Pellets — Best for Small Training Pots
- 5. Ho Yoku Bonsai Fertilizer — Best Feeding Guidance
- 6. TPS Nutrients Bonsai Liquid — Best Small Liquid Bottle
- 7. Gardenera Bonsai Mist — Best Foliar Mist for Indoors
- What to Look for in a Bonsai Fertilizer
- Frequently Asked Questions
Disclosure: Urban Lotus Project earns a commission from qualifying Amazon purchases made through links on this page, at no extra cost to you.
How we compared: we compared 12 current Amazon bonsai fertilizer listings on what each listing states about formula, form, feeding interval and use; we did not test or handle the products, and availability changes.
| Product | Best for | Key features | Buy |
|---|---|---|---|
| Biogold Original | Best organic pellet |
| Buy now →Check current price |
| Perfect Plants Bonsai Pellets | Best set-and-forget feeding |
| Buy now →Check current price |
| SUPERthrive Bonsai-Pro | Best liquid concentrate |
| Buy now →Check current price |
| The Grow Co Bonsai Pellets | Best for small training pots |
| Buy now →Check current price |
| Ho Yoku Bonsai Fertilizer | Best feeding guidance |
| Buy now →Check current price |
| TPS Nutrients Bonsai Liquid | Best small liquid bottle |
| Buy now →Check current price |
| Gardenera Bonsai Mist | Best foliar mist for indoors |
| Buy now →Check current price |
Prices change often; check Amazon for today’s price. As an Amazon Associate we earn from qualifying purchases.
Fertilizer only works as well as the soil it sits in. Bonsai soil should drain in seconds and hold air, which is why feeding has to be frequent; see our guide to the best bonsai soil before you change your feeding routine. For how fertilizer fits into overall tree care, our trees and shrubs guide covers the basics that apply to trees large and small.
1. Biogold Original — Best Organic Pellet
Japanese organic bonsai fertilizer in roughly half-inch pellets, N-P-K 3.5-3.7-3.3, in a 900 g bag.
Check price on AmazonWhy We Like It
- Traditional Japanese organic bonsai fertilizer
- Low, nearly even N-P-K suits steady growth
- Large 900 g bag for a whole collection
- Pellets sit on top, easy to see and remove
| Specification | Details |
|---|---|
| Form | Organic pellets, about 1/2 inch |
| N-P-K | 3.5-3.7-3.3 |
| Size | 900 g |
| Feeding interval | Not stated in listing |
| Best use | Outdoor and indoor bonsai in the growing season |
Biogold Original — compressed specs
Biogold is the product many bonsai clubs and nurseries reach for, and the listing’s numbers explain why it works for refined trees: an N-P-K of 3.5-3.7-3.3 is mild and balanced, so it supports steady growth without the long, coarse shoots a high-nitrogen feed can push on a tree you are trying to keep compact. The pellets sit on the soil surface, and each watering carries a small amount of nutrients down to the roots. Because they are visible, you can pull them off when you want to slow a tree down, such as before repotting or during a hot spell.
Compared with the synthetic pellets on this list, Biogold is the gentlest and the only one that presents itself as a traditional organic cake. The listing does not state a feeding interval, so follow the package directions on how many pellets per pot size and how often to replace them. The same shelf also carries a 280 g BioGold listing with triangular pellets designed not to roll off the pot, if you only have a few trees.
Pros
- Mild balanced organic formula
- Easy to adjust by adding or removing pellets
- Large bag size
Cons
- Feeding interval not stated in listing
- Organic pellets can attract birds or develop surface mold outdoors
- Slower effect than a liquid
Check Biogold Original price on Amazon
2. Perfect Plants Bonsai Pellets — Best Set-and-Forget Feeding
Slow-release 18-6-8 pellets that the listing says feed for 6 months per application; named for juniper, maple and gardenia.
Check price on AmazonWhy We Like It
- One application covers about six months
- Higher nitrogen supports leafy growth
- Lists iron among the included nutrients
- Small bag lasts years for a few trees
| Specification | Details |
|---|---|
| Form | Slow-release pellets |
| N-P-K | 18-6-8 |
| Feeding interval | Every 6 months per listing |
| Size | 5 oz |
| Named species | Juniper, gardenia, Japanese maple |
Perfect Plants bonsai pellets — compressed specs
If you forget to feed, this is the simplest fix on the shelf. The listing describes a one-time application every six months, which suits busy owners and anyone with a ficus or juniper they mostly want to keep healthy rather than actively develop. The 18-6-8 formula leans on nitrogen, which drives leaf and shoot growth; that is useful for a young tree you are thickening or a tropical growing indoors under lights, but it can produce longer internodes on a refined tree.
Against the other pellets here, it has the longest stated interval after The Grow Co and a more nitrogen-heavy ratio than Biogold. The listing also claims a bag lasts years, which makes sense given how little a small pot needs. Use a light hand with pots under 6 inches.
Pros
- Twice-a-year application
- Clear N-P-K on the listing
- Named for common outdoor bonsai species
Cons
- High nitrogen can lengthen shoots on refined trees
- Harder to adjust once applied
- Small 5 oz bag for large collections
Check Perfect Plants Bonsai Pellets price on Amazon
3. SUPERthrive Bonsai-Pro — Best Liquid Concentrate
A 7-9-5 liquid concentrate with macro and trace elements, no urea, diluted for watering and misting.
Check price on AmazonWhy We Like It
- Concentrate stretches a long way
- Contains no urea, per the listing
- Use for watering and foliar misting
- Works in soil and soilless media
| Specification | Details |
|---|---|
| Form | Liquid concentrate |
| N-P-K | 7-9-5 |
| Size | 32 oz |
| Nutrients | Macronutrients plus trace elements |
| Application | Dilute; water in or mist foliage |
SUPERthrive Bonsai-Pro — compressed specs
Liquid feeding gives you the most control: you decide the dose each time you water, and you can stop instantly. SUPERthrive’s bonsai formula is a complete fertilizer with trace elements, and the listing notes it contains no urea, which matters in inorganic bonsai mixes such as akadama, pumice and lava where there is little soil life to convert urea nitrogen. The slightly phosphorus-forward 7-9-5 ratio is a reasonable all-season choice.
The listing says to dilute and use frequently, which is the classic weakly-weekly approach many bonsai growers prefer. A 32 oz concentrate is the largest liquid on this list, so it suits a growing collection better than the 8 oz bottles further down.
Pros
- Precise control over dose and timing
- No urea for inorganic mixes
- Largest liquid volume on the list
Cons
- Needs mixing every feeding
- Easy to forget compared with pellets
- Exact dilution not given in listing text
Check SUPERthrive Bonsai-Pro price on Amazon
4. The Grow Co Bonsai Pellets — Best for Small Training Pots
Gentle slow-release pellets placed around the trunk; listing cites up to 9 months per application and doses by pot size.
Check price on AmazonWhy We Like It
- Longest stated release window on the shelf
- Dosing explained by pot diameter
- No mixing into the soil needed
- Named for indoor and outdoor species
| Specification | Details |
|---|---|
| Form | Granular slow-release pellets |
| Release | Up to 9 months per application |
| Applications | 35+ for 6 inch pots, 20+ for 10 inch pots |
| Size | 5 oz |
| N-P-K | Not stated in listing |
The Grow Co bonsai pellets — compressed specs
This listing is unusually clear about how far a bag goes, with application counts given for a standard 6 inch training pot and a 10 inch decorative pot. You place the pellets around the base of the tree rather than mixing them in, and the listing notes they work with top dressings of gravel, moss, pumice and lava rock. It names a wide range of species, from juniper and ficus to jade, Fukien tea and satsuki azalea.
The gap is the N-P-K, which the listing does not state, so you cannot compare its strength directly with Perfect Plants or Ho Yoku. It is described as gentle and fully balanced, making it a reasonable pick for beginners with mall-bought ficus or juniper bonsai. Our bonsai for beginners guide covers watering and light, which matter more than fertilizer for new trees.
Pros
- Very long feeding window
- Clear dose guidance by pot size
- Works with top dressings
Cons
- N-P-K not stated in listing
- Long release is hard to stop if a tree weakens
- Small bag for big trees
Check The Grow Co Bonsai Pellets price on Amazon
5. Ho Yoku Bonsai Fertilizer — Best Feeding Guidance
19-5-9 slow-release granules with a stated dose of 1 teaspoon per 3 inches of pot width and schedules by tree type.
Check price on AmazonWhy We Like It
- Separate schedules for tropical, conifer and deciduous
- Simple teaspoon dosing by pot width
- Uniform granules for even feeding
- Pitched for recovery after pruning
| Specification | Details |
|---|---|
| Form | Slow-release granules |
| N-P-K | 19-5-9 |
| Dose | 1 tsp per 3 inches of pot width |
| Schedule | Tropicals every 60 days; conifers 2 to 3 times a season; deciduous twice a year |
| Size | 10 oz |
Ho Yoku bonsai fertilizer — compressed specs
The standout here is the instructions. Rather than one schedule for everything, the listing splits feeding by tree type: tropical trees every 60 days, conifers two to three times per growing season and deciduous trees twice a year. That reflects how differently a ficus indoors and a maple outdoors actually grow. The dose of one teaspoon per 3 inches of pot width is easy to follow, and the listing says each granule carries the same blend, which helps avoid hot spots.
At 19-5-9 it is the most nitrogen-heavy formula among the picks, a touch above Perfect Plants, so it suits trees in development more than finely ramified specimens. For a refined tree, use the low end of the schedule or alternate with a mild organic such as Biogold.
Pros
- Species-specific feeding schedule
- Easy teaspoon measurement
- Larger bag than most pellets here
Cons
- High nitrogen for refined trees
- Granules less visible than large pellets
- Not organic
Check Ho Yoku Bonsai Fertilizer price on Amazon
6. TPS Nutrients Bonsai Liquid — Best Small Liquid Bottle
An 8 fl oz liquid bonsai food with kelp and micronutrients, made in the USA; also sold in a 32 oz size.
Check price on AmazonWhy We Like It
- Kelp plus micronutrient formula
- Fast-absorbing liquid delivery
- Compact bottle for one or two trees
- Made in the USA, per listing
| Specification | Details |
|---|---|
| Form | Liquid |
| Key ingredients | Kelp and micronutrients |
| N-P-K | Described as balanced; numbers not stated in listing text |
| Size | 8 fl oz (32 oz also listed) |
| Origin | Made in USA |
TPS Nutrients bonsai liquid — compressed specs
For a single indoor bonsai, a big jug of concentrate is overkill. TPS Nutrients sells this bonsai liquid in an 8 oz bottle, with a 32 oz version on the same shelf when you need more. The listing highlights kelp and micronutrients and positions the formula for compact growth and root strength. It is a good fit for indoor ficus, Chinese elm and jade, where regular small feedings during active growth beat infrequent heavy ones.
Compared with SUPERthrive, the listing gives less detail on the formula, describing it as balanced without printing the numbers in the text. TPS also offers a ready-to-use foliar spray on the shelf if you prefer misting.
Pros
- Small bottle, little waste
- Kelp-based micronutrient formula
- Larger size available
Cons
- N-P-K numbers not in listing text
- Frequent feeding needed
- 8 oz runs out fast for collections
Check TPS Nutrients Bonsai Liquid price on Amazon
7. Gardenera Bonsai Mist — Best Foliar Mist for Indoors
A ready-to-use 3-1-2 fertilizer mist in an 8 oz spray bottle; just a few spritzes per feeding, per listing.
Check price on AmazonWhy We Like It
- No mixing, no measuring
- Gentle 3-1-2 ratio
- Convenient for windowsill bonsai
- Fits a misting routine you already have
| Specification | Details |
|---|---|
| Form | Ready-to-use spray mist |
| N-P-K | 3-1-2 |
| Size | 8 oz |
| Use | Foliar feeding |
| Feeding interval | Not stated in listing |
Gardenera bonsai mist — compressed specs
A foliar mist is the most convenient way to feed a small indoor tree, and Gardenera’s ready-to-use bottle needs nothing more than a few spritzes. The 3-1-2 ratio is a common houseplant balance, and the listing pitches it as free from harsh chemicals. It makes sense as a supplement for indoor tropicals between root feedings.
Foliar feeding alone delivers far less nutrition than feeding the roots, so treat this as a top-up rather than your only fertilizer for an actively growing tree. TPS Nutrients has a comparable 16 oz bonsai spray on the shelf if you want a bigger bottle.
Pros
- Easiest product to use
- Gentle ratio for indoor trees
- No mixing
Cons
- Small dose per spray
- Best as a supplement, not a sole feed
- Can spot leaves in hard-water areas if overused
Check Gardenera Bonsai Mist price on Amazon
What to Look for in a Bonsai Fertilizer
Pellets or liquid?
Pellets and granules feed slowly with every watering and suit people who want low maintenance or who grow outdoors where frequent watering would wash liquids through quickly. Liquids give fine control and fast response, which helps indoors and with trees in recovery. Many experienced growers use both: organic pellets on the surface as a base, plus a dilute liquid every week or two in spring.
Reading the N-P-K
- Higher nitrogen (such as 18-6-8 or 19-5-9) pushes leaves and shoots. Good for young trees you are thickening and for indoor tropicals.
- Balanced or low numbers (such as 3.5-3.7-3.3 or 7-9-5) support steady growth without coarse shoots. Good for refined trees and conifers.
- Late-season feeding for outdoor trees should be lower in nitrogen so new growth hardens off before frost.
Indoor vs outdoor trees
Indoor tropicals such as ficus, jade and Fukien tea grow most of the year, so they can be fed lightly from spring through early fall and sparingly in winter. Outdoor temperate trees such as junipers, maples, elms and pines should be fed from spring leaf-out through late summer and not at all while dormant. Junipers in particular are outdoor trees; our guide to juniper bonsai care explains why.
When not to feed
- For about four to six weeks after repotting, while new roots form.
- When a tree is weak, wilting or dropping leaves from a watering or pest problem.
- During dormancy for outdoor deciduous and coniferous trees.
- On dry soil: water first, then feed.
Signs of too much fertilizer
White crust on the soil or pot rim, brown leaf tips and edges, sudden leaf drop and long, weak shoots are common signs of overfeeding. Flush the pot with plenty of clean water, remove surface pellets and skip feeding for several weeks.
Frequently Asked Questions
How often should I fertilize a bonsai?
It depends on the product. Slow-release pellets are replaced every one to six months or more depending on the label, while liquids are typically used weekly or every other week at a dilute rate during active growth.
Can I use regular houseplant fertilizer on bonsai?
Yes, a balanced houseplant fertilizer diluted to half strength or weaker works for many bonsai. Bonsai-specific products mainly offer dosing suited to small pots and fast-draining soil.
Should I fertilize bonsai in winter?
Do not feed dormant outdoor trees. Indoor tropicals that keep growing under lights can get light, occasional feeding through winter.
Is organic fertilizer better for bonsai?
Organic pellets release gently and are less likely to burn roots, which is why they are traditional. Synthetic products are more precise and work well too when used at the right rate.
Why is there mold on my fertilizer pellets?
Organic pellets can grow harmless surface mold in humid conditions. It usually does not hurt the tree, but you can replace the pellets or switch to a synthetic pellet or liquid if it bothers you.