Help! My Gardenia Bonsai is Dying!

“I have a flowering bonsai tree that last year got leaves on all of it.  It is still in the pot, I have not planted it outside as I live in an apartment.  I normally set it outside in summer and bring it inside during the winter. However, right now I am wondering if the one side of the tree is dead, as no leaves are coming on it, and one side has brand new green leaves emerging.  It currently is inside as it’s winter here.  Should I prune it to just the one side main branch where the leaves are starting? Or wait until Spring to see what happens?” Question from Amy of Madison, Wisconsin

Answer: It appears that several of your gardenia’s branches are dead. To test this, feel the twigs and buds, and do some test scratches to look for green living tissue under the bark. If the twigs and buds are dry and brittle, they are likely dead. If a scratch test shows no living green color beneath the bark, they are dead and need to be pruned off to the point of living tissue. Prune off only dead branches. Living branches should not be pruned in winter but should be pruned right after plants flower, later in the season.

Gardenias go through a sort of semi-dormancy in winter, so they need special care. There several things that could be causing your gardenia bonsai stress, so let’s cover what indoor gardenias need to overwinter in good health.

  1. High humidity: Keeping the pebble tray below the plant hydrated should provide adequate humidity. Humidifiers are also helpful. Also, keep plants away from drying heating vents
  2. Cool night temperatures: Gardenias prefer cool night temperatures between 55 to 60 degrees F in winter and day temperatures up to 65-70 degrees F.
  3. Bright filtered sunlight: Turn the plant weekly if it only gets bright sun on one side.
  4. Lower water: In winter, allow the plants to dry between watering. The surface soil should be dry down to at least 2 inches before you water again. Saturated soil can cause root rot and plant death, especially in the winter months. (At replanting time, consider a well-drained potting mix like Black Gold All Purpose Potting Mix.)
  5. No fertilizer: Do not fertilize plants in winter because they are not actively growing.
  6. Check plants for pests: Spider mites and white flies are two common pests that attack leaves–causing plant stress and leaf drop. Check beneath the leaves for little black specks (spider mites) or tiny white-winged flies. If you see them, clean beneath the leaves with a damp cloth and spray plants with insecticidal soap.

Follow these steps and the living portion of your plant should snap back. Keep me posted on its progress!

Happy gardening!

Jessie Keith

Black Gold horticulturist



Plants are the lens Jessie views the world through because they’re all-sustaining. (“They feed, clothe, house and heal us. They produce the air we breathe and even make us smell pretty.”) She’s a garden writer and photographer with degrees in both horticulture and plant biology from Purdue and Michigan State Universities. Her degrees were bolstered by internships at Longwood Gardens and the American Horticultural Society. She has since worked for many horticultural institutions and companies and now manages communications for Sun Gro Horticulture, the parent company of Black Gold. Her joy is sharing all things green and lovely with her two daughters.

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