On Tuesday, September 29, 2015 at 4:26:20 AM UTC-7, Brooklyn1 wrote:
Hypatia Nachshon wrote:
David E. Ross wrote:
Hypatia Nachshon wrote:

For years, I had a row of Hibiscus along the W. side of the house.
The whitefly infestation was unrelenting.
I tried everything that was on the market, but finally gave up & took them out.

But at the same time I had a large Hibiscus bush on the N. side of the house
that was handsome, healthy, gorgeous flowers in season -- and nary a whitefly!

Unfortunately I don't have a record of the variety either of the defunct or the
existing.

Anybody know if there are certain varieties that are more subject to whitefly? I've been curious for years.

In southern California, the afternoon sun definitely gives more heat
than the morning sun. Morning haze filters the sun; the haze burns away
by noon. The hibiscus on the west side (afternoon sun) might have had
heat stress and were thus more susceptible to insect attack than the
hibiscus on the east side (morning sun).

If whitefly becomes a serious problem in my garden, I do one of the
following:
* Spray with malathion.
* Spray with a systemic insecticide.
* Feed with a commercial fertilizer that contains a systemic insecticide.
* Ignore the whitefly, which will eventually go away.
This all depends on the plant and -- with the systemics -- the proximity
of edibles.

The "bad" Hibiscus was against a block wall, so did not get direct afternoon sun but did get mid-day sun.

That's enough to cook the plants with radiant heat... never place
plants at a masonary wall that receives direct sun regardless time of
day... one hour is 45 minutes too long. If there isn't room to have
at least a six foot space between a masonary wall and plants cover the
masonary wall with wood/bamboo privacy fence, will probably be much
more attractive. Btw, afternoon sun strikes a vertical wall with far
more intensity than when the sun is directly overhead.

The "good" Hibiscus was not on the E. side, but, as I wrote, on the N. Side.
As I wrote, I tried every possible remedy on the market.
I'm still interested if anyone knows why one variety would be so susceptible
but another not at all.

Really a no brainer.

Thanks, I do appreciate the input.

Though this/these Hibiscus are long gone, I still wonder if some varieties are more susceptible to Whitefly. The bush on the N. side, for example, DOES receive hot Western sun in the afternoon. It is against a white masonry porch wall, though it is so tall that most growth is clear of the actual wall. Never had the slightest problem, even in this town, the Home of the Whitefly, which has infested my Lemon tree for decades.

HB