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Oregon Olive Trees™ |
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Oregon Olives |
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Think global - buy local. |
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Oregon Olives |
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Oregon Olive Oil |
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Oregon Olive Trees |
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Trees for Sale |
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Introduction |
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Planting |
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Growing |
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Cultivars |
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What to plant?
First, in all honesty I have to recommend that you plant grapes instead of olives, if you are into farming for the money. There is no doubt in my mind that from an agronomic point of view, if you have a good place to grow olives in Oregon, that grapes will do better and yield more. Particularly here on the hillsides of the Willamette Valley, pinot noir is King.
So, OK, you want to plant olive trees, right? Great! So what is everybody else planting? The top ten varieties planted in California from 1999 to 2004 were:
Arbequina 1,089,900 Arbosana 173,000 Frantoio 118,830 Mission 76,480 Koroneiki 73,550 Leccino 65,461 Manzanillo 58,200 Pendolino 30,118 Taggiasca 15,250 Coratina 11,232
See: California Olive Oil Survey Statistics
So what is the rest of the world doing? Literally everything else! If you like, say, the green cracked olives you had in Provence, find out what the cultivar name was, and plant them! If you have a special bottle of Palestinian Nabali olive oil and love it, plant the trees used to make that olive oil. Give it a shot! And, the odds are you can find some information on how the trees are doing here in Oregon by looking at our cultivar pages!
Here is a list of the world’s top table olive cultivars, according to the International Olive Oil Council:
Spain: Alorena*, Gordal Sevillana*, Hojiblanca, Manzanilla Cacerena, Manzanilla de Seville*, Morisca, Villalonga* Italy: Ascolana*, Nocellara del Belice*, Noccellara Etnea, Sant’ Agostino* Greece: Chalkidiki*, Kalamon, Konservolia Turkey: Ayvalik, Dornat*, Memicik, Memeli Tunisia: Meski*, Chetoui Portugal: Carraquenha, Galega Vulgar Morocco: Meslala*, Picholine Marocaine
* used only for table olives; the others are dual use cultivars.
For those interested in olive oil, here is a link to an excellent presentation made on 04/18/08 by Paul Vossen:
Olive Varieties for Oil Production
When to plant?
Consider this graph of the extreme low temperatures in Salem, Oregon in February, compared with the same Oct.-Dec. SOI average: |
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Extreme cold events occur almost exclusively during La Niña years. See: Oregon Climate Service for more information (and the above graph in context).
Some good news, consider this graph of the current (Dec. 4, 2009) ENSO conditions: |
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The feeling is that we have about reached the peak of this El Nino event, and that it will be classed as “moderate”. Since this index does not change fast in [northern hemisphere] winter months, this means a moderate winter is most likely in store. To see the latest data: Multivariate ENSO Index.
The current [Dec-Jan-Feb-Mar] forecast for the Pacific Northwest, based on the current conditions is for a warmer than normal temperature winter for our area. (orange = A = “above normal”): |
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“El Niño is expected to strengthen and last through Northern Hemisphere winter 2009-2010.” Sounds good! And those who put in groves this spring should congratulate themselves - it looks to be a winning bet. The latest update of this may be found here: U. S. Seasonal Outlooks.
And please, take all this with a huge dose of your own judgment! After all, you can’t believe everything you read on the internet, right?
Where to plant?
Ah, I hate to be negative, but let’s start with what will not work for olive trees and olive production:
Don’t plant where there is ever seasonally standing water, or poor drainage. Olive trees are adapted to arid areas - not swamps.
Don’t plant where there isn’t at least 10 hours a day of sun in the summer. Olives are adapted to areas with intense sunshine, umm, like deserts.
Don’t plant where there is intense root competition. Olives are adapted to areas where they must struggle to get enough water, not to jungle conditions where water isn’t a problem.
Don’t plant where the expectation is an average winter’s minimum will be less than 15 F.
Don’t plant where a temperature of less than 10 F has been recorded in the last ten years.
Don’t plant where the expectation is less than 2,000 “corn” growing degree days (i.e. 50 F base, April 1st to Oct 31st).
Don’t plant where less than 15” a year of water is available (natural or irrigation).
Be wary of planting in areas of poor air circulation (e.g. river bottom land). Ideally, you want to be about 100’ higher in elevation than “the flatland”.
Be wary planting on land with a northern exposure. Olive trees are sub-tropical, and need all the micro-climate advantage you can give them.
Don’t plant on steeper than 10% slopes and expect to use power equipment (tractors, etc). It just isn’t safe.
Whew! Is anybody still with me? An actually, I am not being as exclusive as other sites on the internet are. For example:
Calcium is an essential nutrient, but you don’t need calcareous or even alkaline soils (I am reminded of one of the reasons it took so long to start growing pinot noir in Oregon: the French said we couldn’t do it, being as we didn’t have their [calcareous] soils. They were wrong…). Agricultural lime is one of the cheapest inputs you can buy.
Wind is a issue, but you can do things to manage it. I personally believe that good air movement (wind…) can help alleviate our high humidity problems west of the Cascades.
If you think all of this is pretty restrictive on growing olive trees in Oregon, well, you get my point. And you understand why olives have never been grown as a crop in Oregon. Welcome to growing olives on the edge! |
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Planting in Pots…
If all this is just too much, here is a simple solution: just grow some olive trees in pots! We have had an Arbequina in a 12” clay pot for four years now, and it is doing just fine. Olive trees in larger ceramic pots create a very Mediterranean look, and may fit in particularly well on smaller suburban lots, or even on a apartment patio! Arbequina tree: 11/02/08 |
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These are too small to field plant, especially in the fall. We transplanted these and others into 2 gallon “tree pots”, and grew them a year there before field planting them in September 2008. A newly planted Leccino, Kathy’s Grove 09/17/08: |
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Planting is easy. Just dig a hole; place the tree in the hole no deeper than it was planted in the pot; backfill the rest of the hole; then water. If this seems a mystery, here are the U. C. Extension Service instructions:
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Those of you who have been watching the progression of El Nino have undoubtedly noticed the improved (warmer!) forecasts during 2009. Here is the general expectation for the upcoming El Nino winter, based on historical data: |
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Super High Density, or not?
The Super High Density (SHD) system is solely about making the farmer more money. Period. And that’s not a bad thing! If it works…
SHD is a system of planting growing and harvesting olives, developed by a nursery, Agromillora SA, with headquarters in Catalonia, Spain. The olive trees are typically spaced at 4’ x 12’, and are trained on trellis, irrigated heavily and farmed as a hedge row. Harvest is fully mechanized, typically by use of combing by large machines such as modified over-the-row straddle grape harvesters. There are only three highly selected olive tree clones that can be used in this system: Arbequina i-18, Arbosana i-43 and Koroneiki i-38. These three are all low vigor, precocious and are native to hot regions (Spain and Greece).
There are really only two claimed advantages to SHD, as grown in California and Spain. The major and the minor:
- The main cost of growing olive trees is harvesting, typically assumed to be about half the value of the olives picked (harvest costs of, say, $400.00 a ton for "hand" harvesting). By mechanizing the harvest, the cost of harvest is reduced as low as possible. For an “over-the-row straddle grape harvester” with the appropriate adaptations, that might be as low as $42.00 per ton at 5 tons an acre, on a hundred acre parcel.
- The three varieties suitable are precocious (and were deliberately selected for that reason), and thus lead to a quicker return on investment.
And now consider what is sacrificed by the SHD system:
- Olive trees just don’t naturally grow this way. The natural form of an olive tree is a bush. By trying to force it to grow as a hedge, all kinds of problems start to poke out their ugly heads (e.g. disease, “light management”, pollination and fruit set). Olives evolved under conditions where sunlight was super abundant and root competition almost non-existent. Those conditions don’t really exist in Oregon where olive trees can be grown, and conditions are made even more problematic by tight plantings.
- The SHD groves exhibit alternate bearing to an alarming degree, at a very early stage. Consider data from Spain, presented here:
The different faces of Arbequina
(Presentation given by P. Vossen, Sept 18, 2009; slide 9) Here is the yield data abstracted for Arbosana:
Year 2 306 kg/ha Year 3 17,155 Year 4 8,956 Year 5 19,367 Year 6 7,378
Not only have the trees lapsed into a strong alternate bearing pattern, but the yields are already starting to drop in year 4 or year 6, depending on how you look at the data.
- After about 5 years, medium density groves outperform super high density. Yes. Let me say that again: yields are lower in SHD groves after about 5 years, as compared to medium density. See slide 52 here:
Super-high density Olive Growing
(Presentation given by P. Vossen on Oct 07, 2009. Note Vossen is using High Density when he is referring to SHD. See slide 50 where he defines “High Density” as 1,660 trees / ha; any density greater than 1,500 trees/ha is SHD). I also confirmed this fact as it applies to California groves with A. Devarenne (personal communication, March 2009).
- All three of the olive trees suitable for SHD come from very hot places. The selected clones were trialed and planted in an even hotter place, and yields went up. Some more data (don’t you just love real data?), see slide 116. Here is the yield data for Arbequina:
Catalonia (native area, hot!) 8.7 t/ha Andalucia (Cordoba. Really really hot!) 15.5 t/ha
If anybody has any illusions that Oregon is a hot place compared to Spain, or even northern California, I urge them to visit those areas! Varietals and clones selected to do well in hot areas are almost certainly not the ones we should expect to do best here in cool and even cold Oregon. It isn’t true for any other crop that I can think of, why would it be true for olives?
- SHD olive trees are more affected by droughts and frosts. See presentation by Joan Tous:
http://www.santacruzolive.com/page_tous.asp - Koroneiki is probably not suitable for cold Oregon conditions. However, of the three SHD clones, given the exceptional and unique oil it produces, it is probably the one most worthy of trying.
- The investment cost of SHD is much higher. The SHD system needs trellising and irrigation, both of which are major investments (or may indeed be impossible: e.g. we live in a ground water rights limited area). And of course, the investment in buying so many more trees is a win for the nursery that pushes the system.
- The maintenance costs are much higher. Pruning is the second highest cost ongoing cost (after harvest) of an olive grove, SHD requires more pruning than any other, and more pruning as the grove ages. There are currently no dwarf olive trees for growing olives. All will eventually get to be large trees; it is just a matter of how long it takes. After some amount of time, the pruning becomes unsustainable and the economic life of the grove is over.
- The estimated lifetime of a SHD olive grove is now about 15 years.
- There are other cultivars that are precocious. Examples are Picual and Leccino. Leccino has so far been the most productive cultivar we grow, every year.
- The only olive cultivars that can be used to make the system work are precocious and low vigor. Currently that means exactly three cultivars. You want to do anything else in SHD, you can’t.
- Low vigor is not a good thing for us in Oregon. Just ask anybody who has had olive trees for the past two years in Oregon.
- Management is much more intensive (e.g. water and fertilization schedules).
- Just like any other agricultural product, the more that gets to market, the lower the price. For example, even in early 2009 Arbequina olive oil was selling at a 1/3 discount as compared to other olive oils (private communication with A. Devarenne, March 2009). Expect this price differential to widen, as more of the vast SHD groves world-wide reach harvestable age. Interestingly, no cost study I have seen to date includes this marketing fact of life, although several mention the "possibility".
- The olives are really beaten up by machine harvest. Don’t even think about trying to use them for table olives! This makes rushing them to the mill imperative, before damage to the olives makes it impossible to produce a extra virgin oil.
- Are the “super” harvesting machines available in your area? Do you have a large enough planting to interest them in even doing the work? If you have, say, two acres (a reasonable amount of land to trial olives), I think it totally unrealistic they would even be bothered, as the work of harvest amounts to about 45 minutes an acre.
- These “super” harvesters cannot be used on sloping land. Here’s the story I heard about the first (and so far only) such machine in Yamhill County: the first time they took it out, on perfectly flat ground, they rolled it.
- Unfortunately, it rains in Oregon when olives will be ready to be harvested; and olives will almost certainly not be harvested as mature as they are in California. The olives will be more tightly attached to the trees; any current form of mechanical harvest will be problematical (there are abscission agents for olives, unfortunately they also abscise lots of leaves when used in high enough concentrations to abscise the olives).
- The break even” point for SHD olive plantings has been estimated to be around 100 acres. You just really can’t compete with the large scale farmers, making a “me too” product on a small piece of land. Product differentiation is a marketing necessity for the small producer, as small scale farming does not “pencil out”, and the only profit to be made is in selling your own product. We here in Oregon have learned that with boutique wine production; the California boutique olive oil producers know this too.
- Why be a “me too” sort of guy when there are so many other options for planting olive trees, some even much better for Oregon conditions? If you are a serious grower, with existing groves or not, feel free to drop me line and we can discuss the better options!
I once had an investment banker contact me, who had an extremely wealthy client interested in potentially putting in a couple of thousand acres of olive trees in Oregon. For him, I recommended SHD. In California.
Olive grove layout
There is an excellent discussion of the options for olive grove layouts in the “Olive Production Manual”. Buy the book, understand the issues. We have decided to plant the trees with the modern hexagonal layout, with differing tree spacing (from 20’ to 28’) to suit the philosophy of the grove owners. Other choices:
Since 1980 or so (i.e. the advent of irrigated groves), most European plantings have been around 20’ x 10’ (6m x 3m; more precisely…).
According to the California Olive Oil Commission, most new olive oil groves are being planted at 18' x 12'; or 15' x 15'.
It also seems to me there are two reasonable ways to orient a grove in our climate: the traditional way: with rows lined up north - south to maximize the leaf surface exposure to sunlight; and rows lined up such as to maximize the normal winds blowing down the rows to improve air circulation. Grapes again being a good analogy: in our climate probably the major cultural problem has been mildew, the severity of which is definitely affected by lack of air movement.
Mechanical harvest / tree form?
I basically do not think mechanized harvest of olives will work under our conditions. So, for now, for me, it is a total non-issue as far as planting is concerned, for the home and boutique scale grower. If you are considering putting in 100 acres of olive trees, we can talk more at length - at great length since I will be charging you for that talk! Typing is free, talk costs! See more information on tree form on the Growing page, see Pruning section.
Pollination
The rule of thumb is to plant at least three cultivars, and to have each tree within 100’ of at least one other cultivar. Most olive oils are blends, and since table olives may be intrinsically less suited to our area, you probably want to consider planting at least three cultivars regardless of what you are trying to make. Some cultivars are considered self pollinating, in our climate that might not be so clear cut. Even in California, 10% increases in harvest weight have been noted following the “three cultivar rule”, even with cultivars considered to be self pollinating.
And consider this: maybe you don’t want full pollination. I have an increasing feeling that heavy bearing puts a heavy stress on the trees, and given our harsh winters may well cause tree decline and death. Even in California, it is thought “on” years encourage “off” years; also that table olive growers, wanting to maximize revenue, want bigger olives, and not necessarily more of them. And last, think about this: if you are picking by hand, as undoubtedly you are, do you want to pick a lot of small olives, or fewer bigger olives?
Soil
Here are some recommendations for soil fertility for olives: ph: 6.0 - 8.0; good garden soil (6.5) being considered optimal for our rainy soil types Nitrogen is deficient in every soil. The recommendation for olives is about 40 - 80 pounds an acre, applied annually. It is a common practice by commercial growers to "push" young trees by giving them lots of nitrogen (to make them bigger and thus more productive faster), but for mature trees to cut back, not wanting to make the trees get excessively large (and thus increasing harvest costs). A note on water. Paul Vossen, a University of California guru on olives, has a saying: "Water is the fertilizer for olives". Take that with a grain of salt, remembering that natural rainfall is much scarcer in the olive growing regions of California, and that the farmers down there are very used to using chemical fertilizers to increase yields (and thus don't need any further motivation to do more of that). However, my father, who used to be a farmer in the southern central valley of California, told me even my olives would benefit from a good deep watering once a month during the summer here.
Watering
In our climate, we get a lot of rain (duh!). And you might think that olive trees, being adapted to more arid places, might not need more. But consider this: table olive trees grown commercially typically receive at least a meter of water (from rain and irrigation) per year. In our climate, if you have deep soil, say Jory, you should be able to dry farm olives with no problem. On thinner soils (umm, like, note the field planted olives below; basically there is no top soil…) you will probably have to follow my Dad’s advice too...
Land Preparation
I have put together a photo essay on this; see the Land Preparation page.
Planting
Trees should be of a good size before planting, for several reasons. Bigger trees are more likely to survive in our harsh climate. Darwin rules in the fields, and there are a lot of plants that are extremely competitive in this climate. Even just ordinary weeds growing in the spring can rapidly “smother” small young olive trees!
Here are three Kalamata’s, just as they came to us in “4 inch pots”, on 09/16/07: |