Winter

Learn the individual horticultural requirements for each tree in your collection.
Be aware of your yard's microclimate and alter this guide accordingly.
There are no hard and fast rules for all trees of a species.

December

• Protect trees from very hard frosts, especially citrus, cycads, serissa, and most shohin bonsai.
• Keep an eye on water requirements. DO NOT rely totally on rain to water your trees. Be sure trees are well watered if frost is expected. Remember, freezing is more harmful to dry trees.
  Trim back twigs to refine structure on deciduous trees.
• Prepare soil ingredients and mix soils.
• Study the branch structure of deciduous trees growing in nature with an eye toward refining your bonsai.

January

• Apply dormant spray (i.e., dormant disease control) to deciduous trees. Lime Sulfur is best except for apricots, azaleas and blue foliage.
• Prepare soil ingredients and mix soils.
• Trim back twigs to refine structure on deciduous trees.
• Remove old wire that has started to cut in. Detail wiring may be done with care, but avoid heavy wiring, as damage heals too slowly in cold weather. Always protect newly wired trees from frost.
• Graft pines.
• Watch watering carefully. Do not rely entirely on rain. Make sure trees are well watered if hard frost is expected.
• Cut and store scions for grafting of deciduous trees.
• Photograph and study deciduous trees to enjoy and improve branch structure while leaves are absent.

February

• Apply final application of dormant spray if buds are not moving.
• Prune umes, flowering quince, and other flowering trees that have finished blooming.
• Start to repot deciduous trees that have started bud movement. If buds have not started to swell yet, WAIT!
• Top dress maple and acid loving plant with gypsum.
• Feed conifers (except five-needle pines) with slow release fertilizer, such as rape seed meal or cake (80% cottonseed meal; 20%bone meal), or Osmocote.
• Put slug and sow bug baits under your pots. Repeat monthly if necessary but use caution.