Harvesting rootstock trees

Back in August 2018 we tried an experiment to grow our own rootstock trees, in a technique called a stool bed, and the results are out – we’ve just done our first harvest!

Merv harvesting apple trees from Carr's Organic Fruit Tree Nursery stool bed
Merv harvesting apple trees from Carr’s Organic Fruit Tree Nursery stool bed

So, did it work?

Well, yes and no.  We have two different sorts of trees in the bed. The first is a semi-dwarfing apple, and they worked fantastically well. We planted just 10 rootstocks of a semi-dwarfing variety called MM102 – we think they’ll perfectly suit our customers.

From the initial 10 we layered into the stoolbed trench, we harvested more than 60 trees! And that’s just year 1. We fully expect to get more than that next year.

Apple rootstocks with lots of roots being heeled in
Apple rootstocks with lots of roots being heeled in

The other rootstock in the stoolbed are cherries, which are notoriously hard to grow from either seed or cutting, so stoolbeds are the traditional way of growing them.

An unsuccessful cherry rootstock from the stoolbed
An unsuccessful cherry rootstock from the stoolbed

We started last August by layering 20 cherry Mazzard rootstock trees, and while we also harvested more than 60 of these, they were much less successful, particularly in the root department.

For some (as yet unknown) reason, root development was very slow. Some trees had enough roots that we’re confident they’ll grow well, but some trees only had a couple of roots, and some had none at all!

Lots of the rootstock trees grew over-large, which makes harvesting them extremely difficult – if we didn’t have Merv’s expertise with his secateurs we would have struggled to get them out of the ground at all!

This excessive vigour is also possibly one of the reasons that roots failed to develop on some of the trees, as it seemed to be more of a problem on the larger trees.

Fingers crossed that next year’s crop of trees is smaller, and much rootier!

How old are the fruit trees we sell in our nursery?

Katie in front of Carr's Organic Fruit Tree Nursery
Katie in front of Carr’s Organic Fruit Tree Nursery

This is a very common question from people looking to buy a fruit tree from Carr’s Organic Fruit Tree Nursery, particularly at this time of year before orders close on June 30.

An apple tree seedling in the nursery
An apple tree seedling in the nursery

Unfortunately it’s a bit tricky to answer, and there’s lots of “ifs” and “buts”, but here goes – we’ll try to answer succinctly, without writing a whole essay on fruit tree production!

Collecting peach seed for planting in the nursery
Collecting peach seed for planting in the nursery

Different types of trees go through different processes in the nursery, which take varying periods of time, and have varying degrees of success. But essentially, the process is always the same:

  1. We collect the propagation material – either cuttings, seed, or occasionally bought rootstocks. This usually happens several months before the right time to plant it out, which means storing the material correctly over winter.
  2. We then plant out the seeds or cuttings in spring to grow a new rootstock tree. We use cuttings for figs and to grow plum rootstocks, (which are used to graft both apricot and plum trees), seed to grow apple, pear, quince, peach and citrus rootstocks, and rootstock trees layered in a stoolbed to grow cherry and dwarfing apple rootstocks.
  3. The new seedlings/rootstock trees then grow over spring and summer.
  4. In February, any that have grown strongly enough are bud grafted.
  5. The rootstocks that are too small for bud grafting are left to continue growing to be grafted the following winter.
  6. The next winter, we cut back to the buds, which then grow over the ensuing spring and summer. These trees are then available to be sold the following winter – which is 2 years after the initial seed/cutting was planted.
  7. In winter we harvest the rootstocks that have grown in the stoolbed. They are then planted out as individual trees, and the bigger ones are grafted (along with the rootstocks from last year that weren’t big enough for summer bud-grafting). The smaller ones are left to grow another summer to be bud-grafted next February.
  8. The grafted trees will grow over the following summer and be available for sale the following winter – which is 3 years after the initial seed/cutting was planted.
Merv planting apple seed (which has started to sprout) in the nursery
Merv planting apple seed (which has started to sprout) in the nursery

Hopefully that all makes sense, and explains the basic processes most of our trees go through, all of which are explained in much more detail in our 5 short online grafting courses.

But of course, it’s not quite that simple! A couple of factors can add layers of complexity. The first one is that at each stage of the process, we don’t get 100% success (though we’re always striving to improve our techniques). So when we do the bud-grafting for example, not all the buds will take. The failures will either be late budded using a different technique, or left to grow and be grafted the following winter.

Grafted cherry trees in the nursery
Grafted cherry trees in the nursery

Likewise, not all grafts are successful, and so the failures will be cut back to the original rootstock and allowed to grow for a bit longer before being bud grafted the next summer.

Multigraft plum trees
Multigraft plum trees

Then there are rootstocks that are destined to be sold as multigrafts. These trees are headed in early summer to create the multiple branches we need, or sometimes failed buds will instead be headed to grow multi-branched rootstocks.

Any that branch and grow strongly enough are then bud-grafted with multiple varieties in February, cut back to the buds the following summer, and become ready for sale the following winter. All up, this may take up to 3 or even 4 years since the original cutting/seed was planted.

Sorry to be complicated! Basically, most trees we sell are between 2 and 4 years old from seed to finished tree.

A cherry tree that's been headed to create a multigraft tree
A cherry tree that’s been headed to create a multigraft tree

But do you know what? It doesn’t really matter!

In most cases once you’ve planted them in your garden they’ll need pruning back quite hard to establish the right number of branches in the right place for the type of tree you want to grow, whether that’s a vase-shaped tree, espalier, or something else, so the age of the tree doesn’t really matter. We call this “establishment pruning” and you can find out more about it in this short online course.

Merv and Sas planting rootstocks
Merv and Sas planting rootstocks

Hopefully that helps, and if still have any questions, either ask us in the comments below or shoot us an email.