Mountain Pine

Mountain pine (Pinus mugo) is one of the best types of pine for bonsai.
It is hardy, compact, and tolerates shaping well.
Pinus mugo is strictly an outdoor bonsai.

Advantages:
- short needles;
- slow growth;
- tolerates cold well;
- easily forms a dense crown;
- responds well to pinching.
But it does not like:
- watering mistakes;
- does not tolerate sharp and unskilled pruning.

Light and placement:
- full sun;
- at least 6–8 hours a day;
- protection from strong winds;
- does not live in an apartment.

Watering:
- water only after the top layer has dried;
- in summer — abundantly, but not daily;
- in winter — minimally;
- it is better to under-water than over-water.

Soil
Pinus mugo does not tolerate dense and wet soil.
Ideal substrate (see here)
50% akadama
25% pumice
25% lava (drainage)
It is recommended to add 10-15% organic matter (see here)
pH: slightly acidic to neutral (6-7)

Transplanting:
- Do not remove more than 30% of the roots.
- Do not expose the root collar sharply.
- Shorten the main root gradually.

Formation
Candles (main technique)
In the spring, when the candles have grown 2-5 cm, pinch them with your fingers (not with scissors).
Leave 1/2–2/3 of the length.
This:
- reduces needles;
- makes the crown dense;
- enhances growth.
Needles:
Summer–fall;
- remove old needles;
- leave 5–7 pairs on each shoot;
- open up access to light inside the crown.

Pruning branches:
- late fall or late winter;
- never prune everything in one season;
- pine trees do not have dormant buds — mistakes cannot be corrected.

Wire:
- aluminum or copper;
- apply in autumn or winter;
- check every 2–3 months as it quickly “grows into” the wire.

Fertilizers:
- from April to September (see here)
- do not feed immediately after transplanting and in winter.

Wintering:
Pinus mugo is frost-resistant, but the roots in the pot are not;
temperature: from -5 to +5 °C;
bury the pot in the ground or insulate it well;
protect from wind and winter sun.

Common mistakes:
- keeping indoors;
- overwatering;
- radical pruning;
- poor drainage;
- trying to shape it all at once.