Walter asked for information on eucalyptus varieties.  Trevor Weatherhead
has listed some excellent reference sources.  Eucalyptus species have been
planted extensively world wide and must be valuable nectar sources even
though they are not planted for that purpose.
 
The eucalyptus species existing in the natural bush state have evolved to
fit niche conditions.  For 20 miles around my home 80% of the eucalypts are
a mallee species unique to this area of Kangaroo Island.  As they only
flower every 7 years this means I must look further afield for reliable
nectar sources.
 
The premium honey of Kangaroo Island is produced from Eucalyptus Cladocalyx.
(Sugar Gum)  The tree is so named because the young leaves are sweet tasting
and attractive to cattle.  Unfortunately the sweet taste is not sugar but
prussic acid so stock must be watched to ensure they do not over-indulge.
Sugar Gum have evolved on Kangaroo Island and the adjacent Flinders Ranges
and are magnificent tall trees flowering in mid-summer and producing an
excellent honey flow for approximately 8 weeks.  The flowering cycle
produces an extremely strong honey flow approximately every 3 years with an
average flow in intervening years but Sugar Gum has failed to produce this
year to the consternation of those beekeepers who rely on harvesting Sugar
Gum rather than working all year managing smaller honey flows.
 
The tree does have one disconcerting habit which should be borne in mind.
As all the vegetation is borne at the end of the branch the high branches
have a habit of breaking in high wind, crashing down on passing motorists or
an adjacent fence.  The resulting tree hollows provide excellent nesting
space for cockatoos and possums.
 
Sugar Gum has, I believe, been planted extensively in South Africa.
 
Other eucalypt species producing honey on Kangaroo Island are White Mallee
(E. diversivolia), Brown Stringybark (E. baxterii)  and Cup Gum (E.
Cosmophylla).   Every 7 years or so I do get a good harvest from Kangaroo
Island Narrow-Leaf Mallee (E. cneorifolia).
 
Betty McAdam
HOG BAY APIARY
Penneshaw, Kangaroo Island
j.h. & e. mcadam<[log in to unmask]
http://kigateway.eastend.com.au/hogbay/hogbay1.htm