Plant Doctor Archive

Yellow yuccas

Question MY yuccas (Yucca elephantipes) are a little yellow. I have had two for about three years, one in a large pot, the other in the ground. Both are about 2m tall and both are quite yellow in the leaf. One has a baby at its base, which is also yellow. They have been outside for about three years or so. We are quite close to the coast near Bulls.

Answer  IT sounds as if your yuccas are tolerating the weather quite well, so the most likely problem is lack of nutrients. A good way to fertilise the container-grown yucca is to poke holes at intervals with a stick, going down 10cm or so into the mix, and pour about a teaspoonful of slow release fertiliser, such as Osmocote or Nutricote, into each hole. For such a large plant, you’ll need at least 8–10 teaspoonfuls. Feed again as necessary depending on the longevity of the fertiliser granules — it will be on the label, probably around 6–8 months.

For the yucca in the garden you could use the same slow release fertiliser, or a cheaper option is to use a general all-purpose garden fertiliser sprinkled over the soil about 50–60cm out from the trunk. Avoid getting it on the plant. I would expect to apply at least a couple of handfuls (50–100g per square metre). You could mix it into the soil with a rake or leave it on the surface. For best results, if it doesn’t rain, water both plants once or twice a week for the first few weeks after applying the fertiliser.

Weekend Gardener, Issue 129, 2003, Page 29