Chinese juniper (Itoigawa)

Where Juniperus procumbens is the species most beginners start with, Juniperus chinensis is the species most experienced growers end up with. The Itoigawa cultivar in particular — selected from wild trees on a specific mountainside in Niigata Prefecture, Japan — produces an unusually fine scale foliage in a rich blue-green, and the species' wood carves into deadwood features (jin and shari) more dramatically than almost any other bonsai genus.

This is the juniper behind most of the famous Japanese masterpieces. It's not difficult in any individual aspect but it rewards experience: timing of pinching and wiring, the patience for deadwood to weather naturally, the eye for asymmetric design. New growers should probably start with procumbens and graduate to chinensis after a couple of years.

The two main forms you'll encounter are Itoigawa (fine blue-green foliage, the standard for refined work) and Kishu (slightly coarser, brighter green, more vigorous). Both are excellent.

Water when the surface of the substrate has dried — typically every 2–3 days in summer, every 4–7 days in spring and autumn, every 7–14 days in winter. Chinese junipers tolerate dryness better than wetness; the most common cause of death is overwatering.

Water thoroughly when you water — until it runs from the drainage holes — then let the substrate dry between waterings. This wet-dry cycling is what juniper roots want.

Tap water is fine. Foliage handles overhead watering well in most conditions but avoid wetting it heavily in still, humid evenings.

Light feeding. Half-strength liquid feed every two weeks from May through August. Slow-release organic pellets in spring (April) and early summer (June). Stop feeding by early September.

Heavy feeding produces coarse, juvenile-style needle foliage instead of the fine scale foliage that's the species' main aesthetic asset. Some growers feed mature show-quality trees only with organic pellets and avoid liquid feed entirely.

Very free-draining. Junipers tolerate poor substrates better than rich ones.

Repot every 3–5 years on established trees. The window is late March to early May — wait for visible root activity (new white root tips at drainage holes, or new shoot extension above). Chinese junipers tolerate root work poorly. Remove no more than a quarter of the root mass on healthy trees. Don't bare-root. Preserve the mycorrhizal fungi — they're partly responsible for the species' health.

Keep freshly repotted trees out of strong sun and wind for at least three weeks afterwards. Water carefully — slightly drier than usual — until you see new shoot extension confirming the roots are working.

Junipers are pinched, not cut. Pinch out soft growing tips with clean fingertips through the growing season — May through August. Don't use scissors on scale foliage; cut tips brown immediately and stay brown for months.

Pinch in waves rather than all at once. Work through the tree over four to six weeks, pinching the strongest growth first and leaving weaker areas alone so they catch up. This is how energy balance is maintained.

Major branch removal happens in late winter or early spring before growth begins. Cuts heal slowly — consider leaving stubs to be carved into jin rather than cutting flush.

Heavy structural work is best combined with substantial deadwood. Itoigawa wood carves beautifully and bleached deadwood is a defining feature of refined specimens.

Wire is fundamental to juniper styling. Apply from late summer (August) through to early spring (March). Itoigawa branches are flexible and take wire well — major bends are possible without breaking. Use copper for structural branches, aluminium for finer work.

Wire can stay on for 6–18 months. Check every two months — the bark is reasonably forgiving but wire can still bite in during summer growth flushes. Branches set well and usually hold their position after wire removal.

Be ambitious. Itoigawa rewards dramatic styling — branches bent in tight curves, trunks twisted into spirals, the wood manipulated into shapes that look impossible.

Informal upright, cascade, semi-cascade, windswept, literati, and root-over-rock all work brilliantly. Deadwood is a defining feature of the best Itoigawa bonsai — substantial jin and shari read as natural mountain weathering and dramatically extend the design possibilities.

Formal upright and broom styles don't suit the species. Most refined Chinese junipers emphasise asymmetric, dynamic compositions where deadwood and living veins create visual tension.

Properly hardy in the UK. Down to -10°C with no protection. Below that, shelter from wind. The species evolved on exposed mountains and shrugs off cold; the bigger UK winter concern is damp, not freezing.

Position pots with morning sun rather than afternoon sun in winter — sudden warming followed by hard freezes is harder on roots than steady cold.

Never bring indoors. Junipers cannot live indoors.

Cuttings (semi-hardwood, August–September) — moderate success rate, the standard route. Air layering is possible but slow. From seed produces juvenile needle foliage for many years and is rarely used for bonsai. Most quality Itoigawa material in the UK is imported from Japan or grown by specialist UK nurseries from cuttings of established mother trees.

Generally healthy when grown outdoors correctly. Most problems trace back to overwatering, poor airflow, or attempting techniques the tree isn't strong enough for.