Hi debstuart1- That's correct. You want to plant the tree at least as high as the original soil line otherwise roots can form above the union down into the soil which effectively removes the benefit of having a (semi) dwarfing rootstock. The reason to plant it even higher than the original soil line was talked about by Harvestman (see post below) today: Often the trees will sink a bit in their new hole, especially if it was dug too deep. Also, you'll be adding mulch on top of the soil, which, year after year, becomes a slightly higher and higher soil line. Make sense? -Glenn Here is a link that might be useful: Have you expereinced scion rooting

In my experience about 3 feet (mine only lived for a few years before it died of what I suspect was fireblight). :) Before anyone can answer you have to say whether they are on dwarf, semi-dwarf or standard rootstock. If you know the actual rootstock that will help many help you. An idea of your growing conditions (part of the world, zone, soil type/fertility) would also be helpful.

I think zone 4 might be a bit iffy for apricots unless you give them some extra protection. They do not like wet feet, so I agree with fruitnut. Apricots and peaches also do not like to get their leaves wet too often. They seem to have an endless lists of fungal diseases that just need a bit of damp to grow. Pears shouldn't have any problem with zone 4 and you could probably find a root stock and variety of pear that would be more tolerant of wet conditions, especially if you plant them in raised beds, as advised. Really, you are going to have to get an accurate identification of what diseases your trees are getting, because you can put the trees onto spray programs that will help control a lot of diseases. Also, only buy from reputable nurseries. Check garden watchdog before doing business with any nursery. I suggest that you do not buy trees from the big box stores.

@gardengal- it was carpinus betulus. Which is where we went wrong I think. I originally had the vision of pleaching them as they grew. I had an image from Houzz that led me on that path! Anyways, I've also thought of just replacing the trees just on the ends of the hydrangeas as well. So there is always that option. But as I'm still interested in replacing some if not all of the trees, I'm still researching. As to the comment on extending the bed that is not what I'm needing to do at the moment. We are actually putting in a swim spa with decking area that runs part of that length. Gardens will be changing around that project. So the deciduous trees that interest me for various reasons, ie. hardiness, spring bloom, fall colour, etc., are: Siberian columnar crab apple Columnar Mountain Ash Swedish Aspen "Erecta" Columnar Serviceberry "Obelisk" I was looking at the columnar beech trees, but zone is 5, so that's out. So if anyone could give me some pros or cons for the ones I've listed that would be great.