Japanese garden juniper as bonsai

Placement

Outdoors year-round, in full sun. A juniper will not survive long indoors: light is too low and it cannot go dormant. You can bring it inside for a day or two to display it, then it must go back out.

In winter, leave it outdoors but protect the roots when temperatures fall below about 14 °F, for example in a cold frame or an unheated shelter: in a pot, roots freeze much sooner than in the ground.

Soil mix

A basic bonsai mix, or one that drains slightly faster. Juniper roots dislike staying wet.

Watering

Let the surface dry slightly before watering, but never let the mix dry out completely. Water thoroughly until it drains. In hot, windy summer weather a small pot may need watering once or twice a day; stay alert in winter too, since a dry week can be enough to dry out the root ball. Misting the foliage helps, especially after repotting.

Pruning

During the growing season, pinch or cut at their base, with fine scissors, any long shoots that stick out of the silhouette. Don’t shear it like a hedge: removing every growing tip weakens the tree and turns the needles brown. Thin out pads that get too dense. Junipers do not reliably regrow from bare wood, so always keep some foliage at the end of each branch. Major work is best done in fall or winter.

Wiring

Junipers wire and bend well, even dramatically; wrap thick branches in damp raffia before bending, and take care near deadwood, which breaks easily. Remove wire before it bites into the bark, cutting it at every turn.

Repotting

About every two years, in early spring, in a free-draining mix; very old trees can go longer. Don’t prune the roots too hard.