planted a new hedge last autumn of various types of pittosporums
and they are growing like wildfire. But two of them look like they
have a mould and black spot. What should I do?
the leaves you sent were dry and rather shrivelled, the problem
looks typical of the kind of leaf spotting found on some pittosporums,
especially lemonwoods (Pittosporum eugenioides). But the
good news is there should be nothing to worry about.
This type of spotting
is usually caused by insects, such as aphids or psyllids, feeding
on new growth. As the insect population dies off in winter, the
problem should cease and when you next trim the hedge you'll probably
remove much of the spotted leaves, which will encourage healthy
Pittosporums can usually
tolerate pest infestations with no need for spraying. Check them
next spring and summer and trim off any affected shoots.
Gardener, Issue 171, 2005, Page 24
Reproduced with permission from the former Weekend Gardener magazine. The views expressed here are not necessarily those of the RNZIH.