Bonsai Trees

Season Planner


Bonsai Season PlannerSpring is perhaps the most exciting time of the year for the bonsai enthusiast. This is the time when plans and dreams can be acted upon and enthusiasm is at its greatest.

The trees come back to life with a burst of energy and promise. Buds open, leaves and shoots emerge looking fresh and green. This is the busiest time of the year and there is much to be done.

  • Repot trees - now is the perfect time to improve a tree's appearance by giving it that special pot
  • Protect freshly repotted and tender trees from strong winds, rain and frost
  • Lift trees that you previously earmarked for collecting last year and search for others
  • Check garden centres for the arrival of any new stocks of trees and examine carefully before purchase, especially the root and base structure
  • Dig up trees in your garden which you have been growing on and replace by planting out new stock that will benefit from a period in the ground
  • Style potential material that has an established root system, protecting from frosts
  • Prune out any dead branches or twigs as they become apparent
  • Structural pruning can be carried out, but avoid large branch removal, at this stage, on Chinese elms which will later callous badly, or on pines and spruce, as resin will bleed from the wound and stain the bark. Don't be alarmed by maples and birch bleeding as they will come to no harm. The bleeding can be prevented or reduced by root pruning at the same time
  • Start preparing selected trees that are to be exhibited later in the year by giving them extra protection and attention
  • Repot and prepare all accent plants
  • Reduce your collection if it is becoming too large. This is an ideal time of the year to asses the quality and potential of your trees
  • Check for pests and diseases, especially greenfly which can quickly attack new tender shoots and leaves
  • Update photographs and records, particularly where interesting changes will be made
  • Trees will require watering more frequently as the weather warms and the roots and foliage begin to grow rapidly. You can now look forward to summer


Summer, with its lighter evenings and better weather gives you more time to enjoy your trees. They should now be looking glorious with their full canopy of foliage. However, there are still many tasks that need to be completed.

  • Display trees to their best advantage in your garden. Select a prominent position to display single trees, which can then be carefully studied individually. This may be in the house, but for no more than a day or two
  • Check for pests and diseases. They can easily strike unnoticed and do considerable damage, especially caterpillars
  • Protect against vine weevil, by using preventative glue on all legs of stands, in conjunction with organic nematodes or soil pesticides
  • Regularly feed with liquid fertilisers, and also slow-release pellets made specifically for bonsai. Older more established trees should be fed less than younger bonsai, to encourage fine twiggy growth
  • Keep an eye on watering as transpiration is now at its maximum. Wind can have as much drying effect as a full day's sun. Willows can be stood in a dish of water throughout the summer
  • Prune when necessary as wounds will now heal quickly. Be sure to use wound sealant. Leaf pruning can be carried out in early summer
  • Style and wire trees. Be sure to take before and after photographs
  • Any wire which is beginning to bite into bark should be removed, but do replace if necessary
  • Keeps all weeds in check and remove as soon as they appear
  • Take planned air layerings in early summer, semi-hardwood cuttings and also pot on new seedlings
  • Enjoy walks in potential bonsai hunting grounds where permission has been obtained, looking for suitable trees to collect in the spring
  • Treat driftwood and jinned branches with lime sulphur on a sunny day
  • Let trees grow freely for a period, unless being prepared for exhibition
  • When on holiday, do make sure that you have a reliable friend or neighbour to care for your trees. Demonstrate exactly what the watering procedure should be. A trial run is a good idea
  • In late summer switch to low nitrogen fertilisers, such as those used for feeding tomato plants. This will help branches ripen and harden during autumn


As the bonsai growing period begins to draw to an end, many deciduous trees now reward you with a blaze of intense colour. These changes may only be short lived, but they are dramatic and the colours can vary from year to year, according to seasonal weather. Late autumn will bring frosts that will encourage the trees into dormancy and will not be detrimental to their well-being, as long as they are not severe.

  • Ensure that trees are only fed with nitrogen free fertilisers in the period before dormancy. A sprinkling of bone meal on the soil surface of all trees, particularly pines and flowering bonsai, will be beneficial
  • Take photographs so that the autumn colours are recorded in all their glory
  • Trunks and branches will begin to thicken dramatically, so be on the look out for wire biting in and disfiguring branches. Remove where necessary and replace if the branch moves from its required position
  • Prepare greenhouse or other over wintering accommodation for any trees that will need protection during the winter months
  • Thin out pine needles to enable next year's buds, which are now forming, to receive maximum light
  • Remove excessive berries and fruit from flowering bonsai as these can put a strain on the tree's energy
  • Use a toothbrush or similar to carefully brush of moss and lichens from trunks and surface roots
  • Tidy up, weed and dispose of fallen leaves
  • Take hardwood cuttings
  • Collect seeds from trees and store safely. Sow those that need stratification during the winter


Winter can be a wonderful time of the year, with deciduous trees now devoid of foliage the fine branch ramification and overall structure can be fully appreciated, evaluated and corrected where necessary. Although the weather may be cold, wet and frosty with dark evenings, there are still many things that you can do. These relate mainly to preparation for next year, when hopefully your bonsai will become even better and more rewarding.

  • Ensure that tender and finely branched trees are given adequate protection. They do not like the action of constant freezing and thawing
  • Any trees that are showing signs of being waterlogged should be positioned out of the rain
  • Check for drying out. The trees will need watering occasionally over winter and this should not be overlooked. Water first thing in the morning so that by nightfall the pot is not full of water, in case of a heavy overnight frost
  • Photograph winter images, especially if there is a snow fall. Do not be alarmed by snow as it can help to insulate the roots and maintain a more even temperature
  • Spray trees with a winter wash to remove algae, lichens and over wintering diseases
  • Check with your favourite bonsai nursery when the newly imported stock will be arriving. Make a note to visit immediately so that you have the best selection and the pick of any bargains
  • Take advantage of the lack of leaves, to prune, wire and style. Be sure that you are not leaving a dead branch to replace a live branch which you remove. Protect any trees that have pruning work carried out
  • Winter exhibitions are popular in Japan and this idea is becoming more widespread, so prepare any bonsai which you plan to exhibit
  • Choose a sunny day to clean and re-paint your bonsai display bench, ready for the next growing season
  • Purchase soil, grit, wire and new pots. Begin to plan your repotting strategy and which pots to use
  • Clean out your potting shed in anticipation of the spring activities and sharpen tools
  • Sift and mix soil so that you are fully prepared for repotting in the spring

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