Notes on Rootstocks and Scions

Apple Tree Rootstocks

In order to create a copy of a given variety a cutting or bud from one year old wood is generally grafted on to a rootstock. In days gone by the rootstocks would have been Malus sylvestris or Crab Apple although today there is an industry developing new rootstock forms that are appropriate for a full range of circumstances. At its most basic a rootstock will determine the eventual height of the tree.

Apple Tree Cuttings (Scions)

While it is possible to grow an apple tree from a pip the chances of it producing good quality fruit are not great. Of course commercial breeders do cross pollinate given varieties and thereafter they trial thousands of seeds in the hope of finding the next new thing. Generally, however, the varieties on offer are clones or copies of an original. A present day Cox's Orange Pippin is an exact copy of the original Cox that was raised in 1825.

One year old wood of a specific variety is used to graft onto a rootstock. This graftwood is known as a scion and contains the genetic material of the required variety. Scions are harvested when the mother tree is dormant. A scion from last year's growth contains vegetative buds that will later form leaves and new shoots.

According to advice from Brogdale grafting is best done about a week after the scion is cut. For our part we think as little delay as possible is best even though folk will tell you the material can be stored successfully in the fridge. This is true to a point - you must double bag and avoid excess moisture in the bag - there is no need to drown them.

Before your start consider how you will label each graft. It is essential to be organised because you must not get the variety name wrong. Be mindful that sunlight turns some ink into invisible ink and similarly sunlight will generally make plastic markers brittle after a year or so. Whatever you do don't attach cable ties to the plant - you'll forget they're there.

As you start a good tip is to pop the scion stick in a little water for a few hours before starting. Decide if you are going to graft two buds or one - if you do it well one bud per scion will be enough. Of course there are many different grafting techniques although the most important truth is that much of the cambium of the scion should meet the cambium of the rootstock - that is that the two cut sections should match and align. Do not get absorbed by the grafting police who insist on a locking tongue - just focus on aligning the cambiums.

With the stick in hand cut your first grafting angle then use scateurs to cut an oblique a cut above the bud with the angle shaping away from the bud. Repeat. Then set out your scions (they'll be abour 7cm long) in size order. Match their girths to your 1 yr rootstock. If you can't get an exact match one possibility is to side graft - cut the scion and use your woodworking skills to fashion a matching space on the side of the rootstock. Finally, bear a thought for the grafted bud. Position it to give it the best chance to grow vertically.

Bind the two sections together firmly - we prefer to use breatheable Buddy Tape from Japan-concept.co.uk although other methods are available. Wax the end with beeswax so the scion doesn't dehydrate and pot this up and keep moist not damp. The grafted rootstock will then callous together - the optimum temperature is 20c. Grafted material held below this temperature will bond OK it just takes longer.

You are a hero in my eyes if you create new trees!