A friend of mine has a strelitzia which he is worried about. It's
dropping leaves faster than it's growing new ones, is not down to one
fully open leaf and 3 other developing ones.

The existing leaves look healthy and dark green, and no sign of pests or
diseases.

The leaves which drop simply turn yellow as they might be expected to do
when they reach the end of their life.

He's keeping it in a S window in his kitchen, temperature between 16 and
19 deg F.

Is it just bedding down for the winter, or does it need attention?
--
Kay

Ours is in an unheated greenhouse, with temperatures down to around freezing, and it is exceedingly healthy. I think they probably require less water in winter - might be worth checking that it is not waterlogged.

There's something very wrong there Kay. The Strelitzia shouldn't lose
its leaves like that. First thoughts are damage to the root system
either through over-watering (possible after a re-pot), physical
damage or infestation with root mealybug or vine weevil. The plant
should be carefully knocked out of its pot and the roots inspected.
Healthy roots are plump and white or creamy white. If over-watering
is the problem, the compost will be sodden and the roots will be brown
and rotting. A complete repot into fresh, sharply drained compost
followed by watering only when the compost has dried out will
encourage fresh roots to develop.

Root mealybug will be apparent by the mass of white waxy fibres around
the roots and on the insdes of the pot. Close inspection will reveal
the adults up to 3mm. long on and around the roots. Most on here will
be familiar with the larvae of the vine weevil and damage caused
exhibits as roots eaten through right into the base of the plant.
Drenching the roots with a solution of Provado will deal with the
pests and subsequent careful watering will encourage fresh root
growth. I've only seen vine weevil in Strelitzias grown in soil-less
composts - plants grown in the preferred loam-based, gritty composts
seem relatively problem free.

Dave Poole writes
There's something very wrong there Kay. The Strelitzia shouldn't lose
its leaves like that.

Snip

Thanks.

My friend suspected he may have overwatered and had allowed it to fry
out. When I saw the plant, the compost was dry at the surface and barely
moist underneath. It if that was the problem it'd take time to recover,
so that looks a very likely candidate. It seems to be in a very fibrous
soilless compost, so it looks is if a soil change at the time of root
inspection would be useful.

It seemed firm in the pot, so if VW damage, not yet at the level when I
usually pick it up, ie when the cyclamen or primrose comes clean out of
the soil ;-)

No sign of the powdering you often see round the rim of the pot at soil
level if you have root mealy bug, but that's not to say there isn't any
- with cacti, the plant often looks fine and no sign of anything, yet
when you lift it out the roots are covered in it.

--
Kay