January — A Quiet Season, Yet One of the Most Important in Bonsai

January is the coldest time of the year. Bonsai trees pause their growth and quietly wait for spring.

Although it may look like there is little to do, this is actually a very important season for management — it determines how the tree will look in spring.

No Repotting

January is a full dormancy period. Disturbing the roots weakens the tree, so repotting should not be done.

Only Conifers Can Be Worked On

During winter, only conifers (evergreen bonsai) should be handled.

• Japanese Black Pine

• Japanese White Pine

• Japanese Red Pine

• Juniper

  
  

Deciduous trees should be left untouched until spring.

Winter Work — Shaping the Tree

Because foliage is inactive, winter is suitable for structural work.

• Pruning

• Wiring

• Branch positioning

  
  

Junipers can also be worked for jin and shari.

When wiring, never bend fully in one attempt. Bend only about 60–70%, then continue the following year.

After heavy bending, protect the tree from dry wind. Wrapping the trunk with raffia helps prevent damage.

Needle Care (Winter Work for Pines)

Black pine and white pine require removal of old needles.

Remove last year’s and older needles to improve airflow and encourage spring buds.

⚠ Always cut with scissors — never pull them out (to protect buds)

Watering — Depends on Species

Trees still need water in winter, but frequency changes.

Standard

• Black pine / Red pine / Juniper / Deciduous: once a day

White pine

• Mid-winter: once every 2–3 days, thoroughly

• Too much water weakens the tree

  
  

Always soak the entire root ball, not just the surface.

Fertilizer

• Pines: small amount acceptable

• Deciduous trees: generally unnecessary

  
  

Winter Color Changes Are Normal

Trees often look different in winter.

Normal reactions

• Juniper / Cedar → turns brown

• Cherry → loses leaves

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If the foliage has gloss, it is alive. Water properly and wait until spring (April–May).

If color does not return in spring, the branch is dead.

Placement — Outdoor Is Best

Most Japanese bonsai species are very cold-hardy and should remain outdoors.

They tolerate freezing temperatures without problem. Keeping them indoors for long periods weakens the tree.

If you want to enjoy blossoms or fruit indoors (e.g., plum or cherry),limit it to 3–4 days, at most one week, then return the tree outside.

Some tropical species are exceptions.

Winter Tasks

• Remove weeds

• Water properly

• Protect from strong wind

  
  

Though quiet, this season strongly influences spring growth.

The Meaning of Winter Care

Winter is not when bonsai stop growing —it is when they prepare to grow.

It is not a season for the grower to act, but a season to prepare the environment.

Doing less is the most important work.