The growth habit of pines is different from most other species. The many different recommended methods for pruning pines can give many beginners a real headache trying to work out what to do and when. Here is the Shibui guide to pines….
First, lets look at pine growth habit. Here is a young Japanese Black pine that has been allowed to grow freely for a couple of years.
Note the bare section on the lower part of each new growth and that the 3 year old needles have mostly fallen off. Also note the whorls of branches. These grow from the smaller candles around the base of the strong, main candle each year.
In Spring, candles elongate and needles open – base of candle has no needles. After the new growth has matured in Summer, new candles will form at the tip of the previous growth. The following Spring these new candles will elongate and open like last year. Usually the centre candle will be strongest and smaller candles will open around the base of the strong one. Pine needles live for 2-3 years. Around the end of summer, older needles will turn brown and drop off leaving a bare area.
I find that pine roots grow quite strongly and the pots become full of fine feeder roots after a year or 2 which can make it hard to water and fertilise properly. If you have a pot bound pine you may notice the needles becoming yellow.
Most growers use a slightly more open mix for pines but they will survive in most types of potting mix. Fertilize regularly (every 2-3 weeks when the plant is active, less in winter) with any plant fertilizer.
Japanese Black pines are pretty tough and can be rootpruned quite hard in winter and early spring. I regularly remove 80% of roots when moving trees from the growing beds to pots and 99% of the trees survive and grow on strongly.
Pines are adapted to strong light levels. Shaded parts of the tree will grow poorly and may die so make sure all parts of your tree get plenty of sunlight. I keep my pines in full sun all year round, rotate trees regularly so all sides receive direct sun and remove excess growth so the branches you are going to keep are not shaded by other growth.
The tricky bit with pines is that back buds rarely grow from parts of the tree where there are no needles so always leave some needles when pruning. When buying a pine, look for one with needles or shoots close to the trunk and main branches. Pass up any that have long areas of bare wood unless you think you might be able to style a literati or use the bare areas as a feature.