4-N-1 Combination Fruit trees are popular - in spite of their cost. Let me tell you a little about the extra work that goes into making these premium trees.
Here is a row of Cold Climate 4-N-1 Apples
First, you will notice they are widely spaced in the row. To get a well balanced head, we cannot plant them 6 to 9 inches apart.
There is care in where the buds are placed on the trunk of the tree. Different varieties grow at different speeds. Over time, we have fine tuned the placement of the buds.
For example, Red Delicious is a much slower grower than Yellow Delicious Apple. We put the Red Delicious bud at the top location on the west side because the top bud forces first in the spring and the west side gets the most sun during the growing season. Just the opposite for the fast growing Yellow Delicious - it is put at the bottom location on the east side of the tree. This care to detail has been done on every combination tree.
Each different variety is labeled prior to harvest so the customer knows what is on the tree. Another hidden cost is the number of trees that fail to make it to a sellable 4-N-1 or 3-N-1 tree. When budders get an average of 75% bud stand, statistics tell you that getting all four buds to take and grow on a tree is a challenge. And we throw away any combinations that are 2 varieties or less. So a lot of budding labor and seedling rootstock is planted that never makes it to sales.
Notice how we train each branch to create a well balanced tree. On some limbs, as you see here, they are tied to pull up a branch that wants to grow outward instead of upwards. Other branches are tied to a stake in the ground to pull the branch down.
Is the cost worth it? Well, I sure enjoyed the 4 apple varieties that I trained as an espalier against my back fence.