Question

gardenia leaves   QUESTION: Hi Mr.Crowder,

  Several bottom leaves of my gardenia are yellowing. I did
not change the soil & pot for close to a year since I bought
the plant. How should I remedy the problem?

Regards

ANSWER: Hi Alfredo, All plants, even evergreens, eventually lose the oldest foliage.  Some hold the foliage 1 year, some up to 5 years, so it may be a normal process.  Gardenias however are sensitive to drought.  If they are allowed to become too dry, they shed the oldest internal leaves.  These are the least productive leaves to the plant for making food and by shedding some, it doesn't lose as much water through the foliage.  It's just self preservation.
Gardenias like full to partial sun and like moist but well drained soil.  Fertilize them monthly during the growing season with fish emulsion or liquid seaweed and it should be fine.
It's about time to repot it.  That's a fairly large plant for the pot.  I'd bump it up 2-3" (no more) in pot size.  Jim

---------- FOLLOW-UP ----------

QUESTION: Thanks, Mr. Crowder, for your advice:)Has my gardenia plant
reached flowering size yet? he plant has reached ard 50-60cm  
in height(including the pot)Is it recommended that I
supplement it with fertilizer high in K or just any normal
fertilizer will suffice? Cheers!

Answer
Size wise, it's large enough to set flowers.  It needs to have a period of cool dormancy (a winter# to set flowers, so if you keep it inside all the time, it may not set as many #or any) flowers for a while. If you get some 40-50 degree Fahrenheit nights, set it outside.  It will encourage bloom production, but don't let it freeze.
Use an organic fertilizer most of the time.  Once in the spring, use a higher phosphorous water soluble fertilizer like 15-30-15 or 9-59-10 or just a light dose of triple super phosphate 0-45-0.  Jim