leaves on citrus
HAVE a Meyer lemon tree that produces quite a lot of fruit. The
problem is the leaves turn yellow every year. I have fed with citrus
fertiliser, Epsom salts, sheep pellets and even tried lime, but
nothing seems to work.
are several factors we need to consider. If the new leaves start
off dark green in spring and turn yellow later in summer, it could
be mite infestation. The mites are tiny insects that suck sap from
the undersides of the leaves. They thrive in hot, dry summer conditions,
so you can reduce their effect by spraying the foliage, particularly
the undersides, with cold water in the evening or early morning.
Or spray with an insecticide such as Conqueror Oil or Mite Killer,
making sure to apply it under the leaves and according to the label
Citrus sometimes tend
to yellow during winter simply because of cold temperatures, but
if the leaves don't green up again in spring the problem is probably
lack of nutrients. They need lots of fertiliser throughout the growing
season and often suffer from nutrient deficiencies, especially lack
of nitrogen which causes leaf yellowing, so you need to feed them
regularly to keep them growing well and looking green. In spring,
and again three months or so later, apply citrus fertiliser at around
a handful per square metre to all the soil beneath the tree, and
water it in to encourage strong growth.
Lemons sometimes also
suffer from trace element deficiencies, but regular applications
of citrus fertiliser should supply the necessary elements. Also
worth trying is regular summer watering, deep into the soil if necessary,
once or twice a week during dry periods along with mulching over
the root system to conserve moisture.
Gardener, Issue 183, 2005, Page 31
Reproduced with permission from the former Weekend Gardener magazine. The views expressed here are not necessarily those of the RNZIH.