North American Fruit Explorers mailing list at ibiblio

["Alan Haigh" <alandhaigh@gmail.com>]

I seldom work with stonefruit on dwarfing rootstock.  I did order some English varieties of European plums on citation some years back and in our climate and they worked well, fruiting in 3 years starting from whips.  Euros usually take 5 years here.

 

Most of the European varieties are rampant growers until they start fruiting while the Japanese, which tend to fruit at an earlier age, can continue to be very vigorous for decades.  While most of my customers have plenty of land I try to keep trees fairly compact so the fruit is easier to access and the crops aren't too huge.

 

I have found that vigorous varieties, even on Myro, can be persuaded to a less vigorous growth habit if I use the same principles I described in the article I wrote a year ago for Pomona titled "Pruning by Numbers".  I am sure many of you already understand what I'm about to say but to some it might be helpful to know that the vigor of a scaffold branch is greatly affected by it's relative diameter in ratio to the diameter of the trunk at its point of attachment.

 

If you train a tree by selecting scaffolds that are 1/3 the diameter of the trunk or less, these branches will begin bearing fruit more quickly and thereby begin slowing the vigor of the tree.  In plums this can require a lot of patience, especially Japanese plums, and you may have to remove the majority of annual growth in the first couple of years.

 

If a tree refuses to produce branches of less diameter you can use an old technique of tying down branches below horizontal and attacking the ensuing water-sprouts.  The lowered wood will loose vigor and begin bearing fruit quickly.  Once most fruit trees are in fruiting mode they can be maintained at the size they have obtained.

 

Another technique you could use is to start the trees in large pots (15 Gal) and let some of the roots grow out of the pots.  When the tree reaches about an inch and a half diameter dig the tree up, saving a lot of the outside root, cut the pot away from the roots you've saved and plant the tree.  The root pruning may send the tree into precocious fruiting allowing you to keep it fairly small.  It's worked for me.