MATSUYAMA
BONSAI SOCIETY
Potting and Repotting
How often should you repot? Every three to five years for conifers, two to three years for deciduous trees, one to two years for fruit trees and most tropical indoor trees every two to three years. These times may vary for unusually fast or slow growing varieties. Watch for disease or signs of poor development.
Checklist for potting or repotting
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ideal pot (substitute pot, a little larger)
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pre-screened bonsai soil and plenty of it, suitable for the species
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screen for covering the drain holes and wire to secure it
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string or wire to secure tree in the pot
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chopsticks for tamping soil
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turntable
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root hook
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root pruners
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spray bottle with water in it
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tray (2”deeper than your tree pot) filled with water and ½ tsp. of B1 (Superthrive) and 1 tsp. 10-52-10 transplant fertilizer
Carefully remove the tree from the pot and slightly mist the outside of the exposed roots. Wash the old pot now if you are reusing it. Remove calcified scale with vinegar. Lightly bleach the pot to remove scum and possible disease residues and rinse thoroughly.
Tease the root ball gently apart. Remove stale soil pockets that smell stagnant. Check under the trunk for insects or signs of root rot. Clean this area especially well.
Try the tree in its new or cleaned pot. Assess where and how much roots to remove. Ask yourself if that much is removed will it maintain the health and foliage of the tree. Keep slightly more roots than foliage at all times. Slightly less rootage than foliage may cause the tree to shed an important branch. But, too much rootage than foliage encourages root rot as unutilized roots decay.
Trim roots until the tree is properly placed in the pot. Check from the side to make sure the apex is over the midline of the pot; check and double-check from all angles. Exposed rootage should be visible above the rim.
Add small amounts of soil at a time, and thoroughly tamp the particles into place around the roots. Spend about ten minutes tamping soil into crevices and air pockets. Keep tamping until no more soil can be incorporated into the new planting.
Carefully brush the soil surface to create the landscape you desire. The soil level at the inside edge of the pot should be about one quarter inch below the rim. The height of the largest exposed roots should be about one third above the total height of the pot. Secure the tree into the pot with wire or string as necessary.
Add a B1 vitamin and 10-52-10 fertilizer into the water. The best way to ensure your tree is watered, is to submerge it in a water bath up to the rim of the pot. Leave until all the bubbles are gone or the top of the soil is saturated with water. Remove and let drain. Place tree in a shady location and DO NOT FERTILIZER AGAIN until the tree show signs of new growth and is healthy.
Note: 10-52-10 fertilizer is a high phosphorus fertilizer for strong and rapid root growth. Helps prevent transplant shock, B1 vitamin Superthrive is a good source for B1 – helps improve tree root health.