Lemon Bonsai and Climate
Like other lemon trees (Citrus limon), a bonsai lemon will grow outdoors In USDA plant hardiness zones 9 through 11 if protected during cold snaps.
Elsewhere, it should be overwintered indoors and moved outside to a spot with eight or more hours of direct sun per day from spring to fall. Make the move when spring temperatures are consistently above 55°F (12.8°C).
Expert gardener’s tip: Don’t have any outdoor space? Keep your lemon bonsai in a south- or west-facing window. Supplement its winter light with grow lights if necessary.
Soil and Water
Eventually, you’ll need to replenish your lemon bonsai’s soil. A recommended recipe includes:
- 1 part each of lava rock, peat moss and pumice
- 2 parts kitty litter or baked clay
The moss and kitty litter or clay retain moisture. The porous lava rock and pumice let excess water drain quickly. Without them, the tree’s roots would drown. Water your lemon bonsai only when the top 4/10 inch (1mm) of soil feels dry.
Fertilizing
As a potted tree with limited soil nutrients, your lemon bonsai needs liquid citrus fertilizer throughout the year:
- Feed weekly from March to September.
- Feed monthly from October to February.
Apply the fertilizer at the label’s recommended rate for potted plants.
Pruning and Wiring
Regular pruning encourages dense growth so you’ll have plenty of branches to shape your bonsai tree. Simply cut every new shoot with four leaves back to two.
Wire your tree any time. You’ll need:
- Anodized aluminum wire (1mm, 1.5mm, 2.5mm and 4mm widths)
- Wire cutters
- Wire cutters
- Raffia fiber
- Clean water
- Soak the raffia fiber in water and wring out the excess. Wrap it around the thicker branches so the wire won’t injure the wood.
- Select a branch, cut off the correct length of wire and wrap the wire twice or more around the trunk at a 45-degree angle to the base of the branch.
- Wire the remainder of the branch.
- Hold the outside of the branch with your fingers and bend it to shape along the inside with your thumbs.
- Place the wired tree out of direct sun. Check it regularly and snip the wires off before they cut into the bark.
Use sterilized pruning tools so you don’t transfer disease to the lemon tree. It’s as easy as wiping the blades off with rubbing alcohol.
