What
are the best varieties?
 This
is just about the hardest question of the lot. There are literally hundreds
of different species of olive tree out there ... or more precisely, hundreds
of varieties of Oliva europa, the European Olive.
There
is no established history of olive growing in the Hunter, with most of
the trees being planted since 1990. We simply don't have a proven list
of "best trees for the area" and are still at the "trial
& error" stage of planting various species and discovering which
do better than others.
However,
some information can be given based on what you wish to do with the
fruit. Certain species are better for pickling, others for oil. There
are plenty of proven varieties available, originally from Spain, Italy,
Greece and other Mediterranean countries as well as USA, South America
and Australia.
What
growing conditions are best?
The
olive tree is originally from the Mediterranean area and seems best
suited to a Mediterranean climate, i.e. dry summers, wet winters. As
a general rule The Hunter has dry winters and wet, all year round rainfall
with humid summers, particularly near the coast, and therefore is not
textbook perfect for the traditional climate for growing olives.
However,
the climatic limitations are not serious and can be overcome with care
and attention. As long as you do not have winter frosts below -8°C and
have irrigation water available, you should be able to grow olives successfully
in the Hunter Valley and possibly better than some Mediterranean countries.
The trees do need a period of dormancy brought on by cold conditions
(daily average below 12°C ) to trigger flowering. The trees do not
like extreme cold and will die below -8°C and the requirement for a good
watering during winter can be overcome with an effective irrigation
system.
What
soil type is best?
Olives
like a well-drained soil, so the medium to heavy clay which is found
around many parts of the Hunter is not ideal. With a program of soil
improvement most of the soil types in the Valley can be improved enough
to make growing successful. We would strongly recommend having a comprehensive
soil test done by a qualified soil specialist before considering planting.
This
soil test could be the best $150 you ever spend.
The
area to be planted should also be tested for its ability to drain.
Should
I plant oil or pickling olives?
There is a decent demand for pickling olives and indeed this is
something that anybody can do at home. So, if you are planting half
a dozen trees, it is probably best to look at pickling and if you plan
to plant 10,000, you should at least consider oil.
Oil
olives sell for around $1 a kilo (depending on oil content).
Pickling olives sell for up to $3 a kilo (if they are in perfect condition
and you can find a buyer).
Should
I plant Green or Black Olives?
 Everybody's
favourite question! All
olives start off green and turn black as they ripen. Unlike grapes which
have white and black varieties, an olive tree can give you both green
and black olives, as well as many shades in between.
Unripe,
green olives have less oil but have a stronger, more pungent flavour.
Ripe black olives have more oil but can lack "bite".
Harvest
time determines the colour of the olive and the taste of the oil ...
usually April / May / June in the Hunter.
How
many trees do I need?
A
mature olive tree at about 10 years of age should stand around 3 to
4 meters high and give a yield of around 40kg per year. The tree should
bear for at least 100 years, but many areas of the world experience
"alternate bearing" years with a good crop one year and a
poor crop the next.
Planted
at a spacing of around 5m x 8m, a hectare (2.2 acres) would support
250 trees, which should (!) give you 10,000kg (ten tonnes!) of olives
a year. At $1 per kilo, that is an income of $10,000 a year, but that
will involve quite a bit of work and time. The spacing at 5 x 8 is traditional,
but may not be ideal for all applications. There are some very effective
groves planted at 5 x 5, and the new theory of over-the-row straddle
harvesting seems to work well with 3 x 7m spacings.
How
much will it cost me?
All
up, allow $10,000 per hectare to be on the safe side ($40 per tree is
what I usually quote), assuming you will do much of the work yourself.
Don't forget, somebody has to cut the grass, pull out the weeds, spray
the bugs, tie the trees back up after the storms, prune them into shape
.....
And
remember, you will not get a crop until the tree is at least 5 years
old and they will not bear fruit fully until they are 10 years old.
How
much work is involved?
Plenty!
Initially,
soil preparation could take 12 months, as many of the Hunter soils are
clay-based and need to be improved before planting. The usual problems
are acidity (add lime) and high salt levels (add gypsum). Some areas
also have high Magnesium, Aluminium, Manganese and other imbalances.
In addition, much of the area has low organic material levels so a cover
crop (such as lupins, oats, rye, etc) to be grown and ploughed in should
be considered. One very effective technique has been to plant the trees
on raised mounds to aid drainage away from the roots.
All this should be done before planting as it is so much easier when
there are no trees in the way!
Once
planted the trees need to be protected against attack from rabbits,
hares and kangaroos. The frequent storms and strong winds in the area
mean the trees need to be firmly staked, and regularly checked to ensure
the stakes are still doing their job. It is general practice to train
the trees to a desired shape for harvesting, so allow 15 minutes a tree
to shape them. 15 minutes doesn't sound much, but 250 trees means over
60 hours!
Regular
irrigation and fertilisation should ensure good growth, with more pruning
and shaping !!! Keeping the weeds under control is especially important
in the early years when the root area is small and the tree is competing
with the weeds for nutrient.
Pests
need to be kept under control. These range from birds eating the fruit,
through a variety of insect and scale pests, through to fungal problems.
These are all fairly well understood, and a range of chemical sprays
(some organic) are available.
Picking
- by hand or machine? Whose hands or whose machine?
To strip 15kg of fruit
from a 5 year old tree by hand, just picking onto a tarpaulin on the ground,
took around 30 minutes per person per tree.
That is about 15 trees a day!
250 trees in around 17 days, but you do tend to get bored after a bit
....…
All sorts of harvesting devices are available and new ones
appear every month. Full mechanical harvesting using butt shakers is envisaged
for trees older than 8 years.
Where
do I get more information?
The
nurseries listed on the suppliers'
page often supply information for free or the consultants will assist
with more information but they may charge a fee.
Some
good publications are:
- "Growing
Olives - An Overview" - Olives Australia
- "Olive
Production Manual" - University of California. Available from
Olives Australia and bookstores specialising in agricultural books.
- "Australian
olives - A guide for growers and producers of virgin oil" -
Dr Michael Burr. Available from AOA or bookstores specialising in
agricultural books.
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