Article updated on 04 June 2016 The question, will my olive trees flower and fruit in a warm climate with a mild winter? Is answered!
I love eating olives and olive oil so when we finally moved to our acreage one of the first trees I planted was a Manzanillo olive tree. In fact, for our house warming we were given a Manzanillo olive tree as a gift from a friend.
Over the next few years, the two olive trees grew very well and although they were still rather young I had the feeling they should be producing the odd olive by now or at least flowering. So, I started researching olive growing and quickly found out olives will indeed grow well in a warm climate (and even thrive) but apparently olive trees needed a prolonged winter chill under about 4 ºC for a sustained period in order to trigger flowering and subsequently fruit formation – and I just happen to live in a subtropical climate near the coast… Bugger. More on my Manzanillo olive trees later.
Manzanillo olive tree flower buds (image above)
Mind you, trying to find any information about growing olives in my part of the world (Brisbane and surrounding North Coast) was a frustrating experience. The only examples I could find of olive growers anywhere near me was inland or up in the hills where it was obviously cooler through winter.
Olive trees actually love growing in an all year round warm climate because the lack of a “winter” enables the tree to continue growing without any down time over the dormant winter months as would happen in a 4 season’s climate.
This means in my area (close to the coast and subtropical) olive trees grow extremely fast and often big! However, the downside is with little or no chill factor olive trees
won’t (may not) flower and if they don’t flower you obviously can’t get fruit.
I’d see olive stands at our local markets and ask if they were locally grown but each time they were from inland or south.
Still, I found it hard to accept that olive trees wouldn't fruit in my location and with the increasing breeds of other cold climate trees being cross bred to create low chill varieties (like plums, and apples etc) I thought, "Surely there is a low chill olive able to be grown in my part of the world."
Helena Olive (from St Helena Island)
My large Helena olive trees and the silvery foliage make them blend into the natural surroundings easily (image above).
So I kept searching for an example of an olive tree which did fruit in my area and one day (several years ago now) I saw a stack of olive trees for sale in my local nursery called Helena. I asked the horticulturist in the nursery where these plants came from and amazingly, she told me the very local story of the Helena olive which came from St Helena Island just slightly NE of Brisbane in Moreton Bay (only 45kms south from me).
I guess to say “originate” from St Helena Island would be a stretch because the olive was actually bought to the Island from Europe by a magistrate in the 1800’s when the Island was a penal colony.
Apparently, the olive grew so well and fruited in this hot subtropical climate that the prized olive oil was exported back to Italy!
Needless to say, I purchased two trees immediately because it was obvious the claim "olives won’t flower in a subtropical climate" was wrong (for this olive tree anyway). That was about 5 years ago now and my Helena olive trees are about 6 metres high but they still haven’t fruited. Update: A few years later (2016) I can happily state my Helena olive trees have finally flowered and produced a handful of fruit – hopefully, next season will be better as is often the case once olive trees start fruiting the harvests usually improve a little each year.
A few years ago I took a cutting from one of the Helene olive trees and successfully grew another tree so now I have three Helena olive trees and every season around the end of spring I start stalking my orchard hoping to see some flower buds emerge.
Nevertheless, my hopes for my collection of Helena olive trees finally flowering haven’t faded because I have also read an olive tree can take up to 7 or more years before it first fruits. If this is correct, I should have some Helena olive fruits very soon or at least within a few years’ time.
Meanwhile, as insurance I planted a further two more olive trees called Arbequina (from Spain). I found out this variety of olive tree fruits early and also is renowned for flowering in low chill conditions.
This proved to be totally true with my Arbequina olive trees flowering and fruiting within the first year of planting. The only issue I have at the moment is the small number of fruit being produced due to the size and age of the trees. Also, the fruit size is rather small compare to other olives. So the lack of fruit and its size has hardly made it worth the effort to brine and make olives to eat, although, I do admit to making a small batch of pickled olives with the meagre amount I managed to pick which turned out alright.
See this article for an update on our Arbequina olives and how to cure them.
Back to our Manzanillo olives
Now back to my Manzanillo olive trees, which I mentioned at the start of this post. These two trees are my oldest olive trees 7-8 years old and with the uttermost excitement I can finally say this spring one of my Manzanillo olive trees is finally in full bud!
This means all things being equal, I should get a good crop of medium to large olives from my tree. It also means the literature about olive trees requiring an extended chill period is not necessarily true and may in fact be a total myth.
Manzanillo Olive trees have a different growth habit than the Helena variety in the way that the Manzanillo has a default tendency to grow more like a bush whereas the Helena olive tree as a very upright growth habit (like a normal tree).
Update: In fact, the fruit harvest didn't at all match the flowering when this article was originally posted and we hardly got an olive that year; however, things have improved dramatically as you can see at the end in the conclusion.
Not the best picture (above) but the size difference and growth behaviour between the Helena and Manzanillo is clear
I always deep down suspected my olive trees would bear fruit even though I lived in a warmer climate with a mild winter and it seems I was right. However, the interesting thing about my experiment was the length of time before finally flowering which was a pretty significant 7-8 years!
Olive trees in colder climates (not freezing) tend to start fruiting almost immediately and as the tree matures it obviously produces more fruit. But perhaps in warm climates like mine olive trees need to grow to full maturity before flowering? I think this is the case.
Therefore, for those who do live in warmer climates with a very mild winter there is still an ability to successfully grow olives as long as they are prepared to wait for several years (even close to 10) before seeing their first fruit.
Nevertheless, I still need to prove my theory about olives taking a little longer to fruit in a low chill climate with respect to my Helena olive trees but I am confident they will flower eventually Update: Yes they did flower. I wish I could have found an article like this when I was researching if olives would be worth growing in my location several years ago because it would have put my mind at ease knowing my trees will eventually flower and fruit. Hopefully, this helps someone else trying to find the same answers today.
So in the end, the answer to the question: Will an olive tree flower in a subtropical climate with mild winters is… YES! …Hallelujah
If you would like to discuss olive growing and/or olives in general why not join our friendly forum and have a chat – we’d love to see you there.
Just a quick update – last season (2015) we ended up harvesting 1 kg (2 pounds) of fruit from our Manzanillo olive trees, which isn't much, but they do taste great! I'm hoping the trees will fruit better as they mature further – if you'd like to see how I cured our olives for eating then go here to our forum and read this thread on curing olives.
This season (2016) we harvested 8kgs of Manzanillo olives from our two trees – naturally, we are pretty wrapped with this outcome. Follow the link above to our forum and read through the to second page where I'm currently curing them in a large beer fermenting container and it's going very well!
Curing manzanillo olives in a beer fermenter with brine (image above)
Mark Valencia Editor SSM
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