Asked May 22, 2017, 10:12 AM EDT
We have 2 dwarf apple trees. A honey gold and a sweet sixteen. We have room for one. How far from our water/sewer line do we need to plant one and will a purple flowered crab apple pollinate it? Thank you!
Thank you for the question. Each type of apple tree has a short bloom time in the spring in which the tree must be pollinated, usually by bees. This bloom time lasts about a week for each different type of apple tree. But not all apple trees bloom at the same time. Almost all apple trees bloom within a three- to four-week period in the spring. When your tree is pollinated, you must have another type of apple tree within 500 feet that blooms the same week(s) yours does. Apple trees have been divided into three bloom time frames: early season, mid-season, and late season. Your honey gold and sweet sixteen are mid season bloomers so should be able to pollinate each other. If you plant another apple tree, try to pick a mid season bloomer like Honeycrisp Cortland, Regent, Red Haralson, Haralred, Gala (blooms early to mid-season) , Jonagold, or Fireside.
Most crabapple trees bloom for longer periods of time than apple trees so are good pollinators. If you have one, it will do the job.
The planting site should be located at least 12 feet from a major underground utility line for large trees (Gilman 1994). Dwarf apple trees will have a smaller root system so could be planted a bit closer. A common misconception about tree roots is that they actively grow into sewer and water lines. Roots will follow a path of least resistance and only grow into sewer and water lines that are broken. Here's a good publication on considerations before planting trees in urban locations: http://articles.extension.org/pages/67466/urban-tree-planting-part-1:-site-selection
Thank you for contacting Extension.