Uncle Bill's Bonsai Tree Fertilizer for Fall & Winter - No Nitrogen 0-10-10

Late-Season Bonsai Feeding Without Added Nitrogen

Uncle Bill’s 0-10-10 is a specialized liquid fertilizer for established outdoor bonsai during the transition from active summer growth into fall.

It supplies phosphorus and potassium without adding nitrogen. This makes it an option for bonsai growers who want to stop adding nitrogen late in the season while the tree and its roots are still active.

The simple explanation: Use a complete fertilizer during the main growing season. Use 0-10-10 only for a short late-season feeding period, then stop when the tree becomes dormant.

This is not a complete, year-round fertilizer and it is not intended for feeding a dormant tree throughout winter.

What Does 0-10-10 Mean?

• 0% Nitrogen: Does not add nitrogen during the late-season transition
• 10% Available Phosphate: Supplies phosphorus used in energy transfer and normal root and flower functions
• 10% Soluble Potash: Supplies potassium used in water regulation, enzyme activity, and normal plant functions

Fertilizer cannot force a tree into dormancy, guarantee winter survival, or correct problems caused by poor watering, weak roots, disease, or improper winter protection.

Which Bonsai Can Use 0-10-10?

It is best suited to established, cold-hardy bonsai that live outdoors and are still healthy and active in late summer or early fall.

Examples include:

• Japanese maples and other deciduous maples
• Chinese and Japanese elms
• Hornbeams and beeches
• Oaks and other cold-hardy deciduous bonsai
• Junipers
• Pines and other cold-hardy conifers

Timing varies by species and climate. Follow the tree’s condition and your local weather rather than relying on a calendar date alone.

When Should I Use It?

Consider switching to 0-10-10 after the strongest summer shoot growth begins to slow, but while the tree remains healthy and the soil is still warm enough for active roots.

• Deciduous bonsai: Use during the late-season transition while the foliage remains healthy. Stop at leaf drop or the first hard frost.
• Pines, junipers, and other evergreens: Use only while the soil remains unfrozen and the tree has not entered winter dormancy.
• During winter dormancy: Do not fertilize. Water according to the tree’s needs and provide appropriate winter protection.

How to Use Uncle Bill’s 0-10-10

• Mix 1 tablespoon per gallon of water.
• Apply enough mixed solution to water the soil normally.
• Allow excess solution to drain completely from the pot.
• Repeat every two weeks during the limited late-season feeding period.
• Stop at leaf drop, the first hard frost, or when the tree becomes dormant.

You do not need to pour the entire gallon onto one bonsai. Use only the amount of mixed solution normally needed to water the pot.

Beginner tip: If the soil is bone dry, moisten it with plain water before applying liquid fertilizer.

Switch—Don’t Stack

0-10-10 should not automatically be added on top of BioGold, Bonsai Thrive, Uncle Bill’s 3-3-3, or another primary fertilizer.

If your tree has been receiving pellet fertilizer, allow the current dose to finish or remove the pellets if they are contained in fertilizer baskets. Then begin the short 0-10-10 late-season schedule.

More fertilizer is not better. Using several fertilizers together can supply more nutrients than a small bonsai pot requires.

When Should I Not Use It?

• Do not apply it to frozen soil.
• Do not apply it to a fully dormant tree.
• Do not apply it during drought or severe heat stress.
• Do not apply it to a sick tree or one with an unresolved watering or pest problem.
• Do not apply it immediately after repotting or major root pruning.
• Do not use it as the only fertilizer throughout the growing season.

Wait to fertilize a recently repotted or stressed bonsai until it has stabilized and resumed normal growth and water use.

Can I Use It on Tropical Bonsai?

0-10-10 is generally not the best routine fertilizer for tropical bonsai growing indoors. Actively growing tropical trees normally need a complete fertilizer that also supplies nitrogen.

For everyday tropical feeding, use a complete fertilizer such as Uncle Bill’s 3-3-3 or Bonsai Thrive. Choose 0-10-10 only when you have a specific reason to follow a no-nitrogen program.

Can It Make My Bonsai Flower?

No fertilizer can create flowers by itself. Flowering also depends on the species, maturity, light, temperature, pruning schedule, and seasonal care.

For a regular flowering-bonsai feeding program, consider a flowering fertilizer such as Hanasaku. Use 0-10-10 only when a species-specific or late-season program calls for a nitrogen-free formula.

A Simple Seasonal Feeding Plan

• Spring through summer: Use a complete primary fertilizer appropriate for your bonsai.
• Late-season transition: If desired, switch to 0-10-10 while the tree and roots remain active.
• Winter dormancy: Stop fertilizing.

What You Receive

One 8-fluid-ounce bottle of Uncle Bill’s 0-10-10 concentrated liquid bonsai fertilizer.

When mixed at 1 tablespoon per gallon, one bottle makes approximately 16 gallons of fertilizer solution.

For plants only. Do not ingest. Keep out of reach of children and pets. Follow the directions on the product label.