GARDENIA grandifolia

• Age
  • Planted 11th September 2004 near shed. Purchased Mid 2002.
  • Small leaf ones in pots purchased Oct 2002.
  • Two behind shed planted Early 2006
• Where it's Growing
  • Shaded positions in cool damp areas.
• Upkeep
  • Have had to replant these into more shaded positions around the garden. The small leaved ones needed to be put into pots then put in very shady spots under the Southern side of the house. We need to regularly water, mulch and fertilise these. But then they look great.
• Growth Patterns
  • Most of these are growing very well. Especially the Grandifolia one behind the shed. Nice healthy big leaves.
  • Flowers mid to late Spring
• Native to southern China, Taiwan, Japan and nearby regions of the subtropical eastern hemisphere. Requires acid soil, ideally moist and high in organic matter, but well drained. Partial shade to sun. Moist to average soil.
• Future Notes
  • I gave all of these plants cow manure, dynamic lifter, mulch & liquid fertilisers today (26.9.06). They should soon thrive!
  • Yellow leaves
    One of the most asked questions about Gardenias is the yellowing of older leaves in late winter and spring. This is usually a sign that the plant is moving its magnesium to the new growth. In the beginning of spring feed with Epsom Salts (Magnesium sulphate) will usually solve this problem. To avoid getting other nutrients out of balance, only apply Epsom Salts no more than once a year.
  • Buds falling or failing to open and going brown: Gardenias tend to keep producing flower buds right through autumn even though their growth is slowing. They will often hold these buds right through winter and drop them in spring. This is fairly normal. The buds can also drop as a result of being damaged by weevils or leaf hoppers.
  • Yellow leaves (particularly seen in spring): In the past leaf yellowing has generally been attributed to a magnesium deficiency and treated with applications of Epsom salts (sulphate of magnesium) but the plant is probably more in need of an all purpose fertiliser and a good watering. Apply fertiliser in spring when weather begins to warm and yellow leaves begin to show.
  • Nematodes: If the yellow leaves don't pick up after fertilising and particularly if there is wilting and if you have a sandy soil, check for nematodes on the roots. Nematodes cause cream, warty lumps on roots (about the size of a match head), yellow leaves and wilting. You could treat the soil with Nemacur, but this is a potent chemical which we do not recommend for general use. If the area is sunny, a planting of marigolds may also help deter the nematode.
  • 13.8.07- Potted gardenias very healthy with lots of flower buds. Gardenia grandifolia near shed very healthy but some grasshopper damage. Other plants behind the shed are ok with 'some' new growth.