spots on yucca
yucca had grown too large for the lounge, so about a year ago I
planted it outside. But within a month or two brown spots appeared,
increasing with time. Now all the new leaves soon turn brown at
the tips with spots all over the rest of the plant. There are always
a lot of spiders and webs on the plant, but no sooner do I clear
them away than they come back.
looks like your yucca is suffering from a combination of cold temperatures
and poor drainage. They grow best in warm, relatively dry conditions
and need free-draining soil. The cold winter nights you can get
in your area are probably pretty close to the limit yuccas can endure,
but the fact that it's already survived one winter shows how tough
yuccas are for a plant that grows best in the sub-tropics.
If you can transplant
it to a more sheltered spot in the garden, say, close to nearby
trees where it will be better protected from frost but where it
still gets plenty of sun, then the colour and growth will probably
improve. And rather than plant it directly into the soil, build
up a mound of bark or growing mix from the garden centre, about
50cm high by a metre across, and plant in that so the root system
is above the surrounding soil level. This will improve drainage
and the growing mix will also stay warmer and so encourage a healthy
In winter you could
cover the plant with a couple of layers of frost cloth for extra
protection on those clear nights when the temperature really drops.
The spiders won't do any harm, their webs just look unsightly.
Gardener, Issue 186, 2005, Page 33
Reproduced with permission from the former Weekend Gardener magazine. The views expressed here are not necessarily those of the RNZIH.