October 2011


One of the most frequent questions we are asked is “How far apart should I plant my trees?” 

Pears in a High Density planting

The answer to that question isn’t as simple as it first seems.  Many factors go into it including the variety of tree within the species (example Honeycrisp and Winesap apples grow totally different), rootstock, soil type and area of country.  However, the most important factor is really the training or pruning method used.  Most fruit tree types can be trained to increase density, or trees per acre, and also the ultimate size of the tree. 

In the late 60’s the apple growers in this country were starting to be faced with a decline in suitable farmland and also the first competition from imports.  As time went on it became obvious they would have to get more production per acre to keep up.  Not only did this involve a higher density

Pear production in Australia

planting but also required more mechanized handling and harvesting to compete against lower wages. 

Prior to the sixties semi-dwarf trees started to come into vogue and increased the production per acre. Now apple trees were easier to pick and less fruit was lost because it was out of reach on high branches.  Orchards with larger trees might have 100 per acre, now we were approaching 400 per acre.  For comparison we have a density of about 300 per acre at our farm.  A whole new terminology has been developed to discuss what used to be called “spacing”.  We now have the following terms to tell how many trees are commercially planted per acre:

Spindle System of training

Low Density           <  400

Moderate Density   400-1,000

High Density           1,000 – 2,000

If that weren’t enough now the move is to even higher numbers and we have;

“Very High Density” at 2,000 – 3200 and of course  “Ultra High Density” at 3200 and above trees per acres.  I don’t know what will come after UHD, maybe SDHD for Super Dooper High Density?

The pictures shown are generally in the “Moderate High Density” or “High Density” crowd.  As an example if you planted trees 3 feet apart and had alleys of ten feet between the trunks, you would “only” have about 1,250 per acre!  If the old orchards were like people in New Mexico, the new commercial ones must be like people in downtown Manhattan. 

Tall Spindle System on Apples

So to answer the question “How far apart should you plant your trees?”   I guess it depends…  For some reason I am reminded of the old saying. “Just because you can do something doesn’t mean you should do it”

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 The jujube is considered rare (or at least very uncommon) in cultivation in the United States. It’s production can be measured in trees instead of acres, so its not surprising that there is a lack of knowledge and confusion about this fruit crop.  Add to that the cultural, diplomatic and language barriers with China and it is understandable that this fruit has not taken off with American growers or consumers.  This is an unfortunate situation because this fruit crop is extremely well suited to growing New Mexico. For small growers and producers of value added products such as specialty jams, sauces, pastries etc. this could provide the edge they need to be profitable.  When you include our growing asian population that has an existing demand, it makes for a bright future for the grower who is an innovator and gets in early. 

We currently are growing  11 cultivars Li, Lang, Shuimen, Shihong, Sugarcane,  Honeyjar, Redlands#4, GA866,Chico, Norris and Sherwood.  Based on our research and taste testing at Alcalde we will probably add the varieties  Tsao, Lin, Yu, Ant Admire, Don Polenski and Shanxi Li.  This will be our “mother” orchard block where we will develop scionwood for grafting new trees. From these we expect to have a continual supply and to also be able to possibly try crossing some of the best ones. We are very happy with the ones we currently raise and were impressed by Don Polenski and Shanxi Li at the tasting in Alcalde.  The others are the best varieties from hobbyists around the country.

 Last week Matt and I took a short road trip to Alcalde, NM. to attend a workshop on Jujubes.  A tiny hamlet on the road to Taos, just north east of Espanola, it is home to maybe 100 families.  It is also home to the NMSU Sustainable Agriculture Science Center.  At this location some research has been done into different fruit varieties in an organic growing situation.  Mostly this has been trials with blackberry and raspberry in 2003 thru 2006.  After that several varieties of Jujube were planted and monitored. One of the interesting things is that even though the location is 90 miles north of us the weather and temperature parameters are almost identical to our location.

The fruit production there is now under the care of Dr. Shengrui Yao. She received a M.S. in Horticulture/Pomology from Beijing Agricultural University and her Ph.D. in Horticulture/Pomology from Cornell University.  She hosted this workshop and tasting event for about 40 growers, gardeners and other government agency employees.  Shengrui is the perfect person to teach about this rare and unusual fruit from China.  She has the unique perspective of having been raised with a fruit that many in the western world have never even heard of, much less tasted.

 

Even with most picked this jujube tree's branches are bending under the fruit load

The Science Center has an orchard of about 40 trees of maybe 10 varieties that are 6 years old. They have just planted 100 young trees, 25 each of 4 varieties. She is trying to get grant money to fund research for these as a commercial crop for New Mexico and seems to be the only person at any university or research facility in the U.S. that is studying them.   There are about 700 cultivars in China today, however there are maybe only 40 in the United States.  With relations and import rules being what they are it is unlikely that we will be seeing new cultivars anytime soon.  The good news is that many of the varieties here are every bit as good as any of the commercial crops in China, so we may not really need any new types.  Another interesting note is there are no developed hybrids of Jujube, all named varieties are cultural selections. 

Our main purpose for going to the workshop was the tasting session.  Not only did we hope to try some varieties we don’t have, but also to test them in different stages of development to see where

Jujube in various stages of ripening, the side facing the sun turns mahogany colored first

is the ultimate ripeness for fresh eating.  More about that later.  The jujube is not really broken into classes and there are many ways it could be.  For example some varieties are good only for fresh eating, some only for dried and some work for both.  Another way is the fruit shape.  There are elongated, oval, round, gourd, teapot and apple shapes. However I think the best way to classify them might be by maturity: early, mid and late season varieties.  Some of the late season varieties require a longer growing season to mature than we can provide in the mountains.  Albuquerque or further south like Los Lunas would be fine for them though.

Even though jujubes have been cultivated in China for more than 4,000 years their use on the mainland is changing. In 1990 almost 90 % of the jujubes were sold as dried fruit. That has changed to 60% dried, 30% fresh and 10% processed.  This may be in response to the cultural changes that have happened in China more than the fruit’s development.  As China gains a middle class more people have refrigeration and so don’t require a dried product for storage and also more have a disposable income to buy a processed product.

For our purposes here inNew Mexico the benefits to growing the Jujube are many.  I won’t say that they thrive on neglect, but they are hardier than many fruit trees.  Once established they are very drought tolerant.  The bright glossy leaves are like citrus in that they hold in moisture and seem to have a shiny, waxy coating. 

Jujube trees have light branching. This one has good horizontal branches

They like our alkaline soil which most fruits do not.  The amount of heat they can tolerate seems to have no upper limit.  We know they are cold tolerant to -25f and just have not been really tested past that point although I suspect they can live way below it once established.  Most varieties are self fertile but will set a larger crop if you have two and that is what we are recommending at this point. They flower very late and avoid any freezes so you always get a crop. No known New Mexico pests or diseases.  Minimal to no pruning required.  This is about all you could hope for in a fruit tree!

As for taste: most have a sweet apple-like flavor and texture with a hint of almond aftertaste.  The fruit is not quite as juicy as an apple and of course if dried it is different altogether.  It is also called the Chinese Date because of the size and appearance when dried, however they are not quite as sweet or  gooey and sticky as palm dates.

I think if the United States got behind this as a commercial crop, our plant breeders could improve jujubes the way the crabapple was changed to modern grocery store apples.  In 30-50 years we could see a new fruit crop completely.  After all the blueberry got it’s start that way after WWII and now is a major crop and staple item in our diet.

See The Upcoming Part 2 for Tasting and Variety pictures.