OPERATION: Apfelbaum (Apple Tree)

A bit over 2 months ago I was asked by my Father-In-Law if I would like to prune his two apple tree's. Of course I said yes, why not? It's not like I haven't done this kind of thing before*. Given that there had been consecutive days with temperatures in the double digits (just) it was something I better get onto quickly, the new growth bud's were well on their way. In that last week or so I had noticed how many more plants were starting to put a lot of energy into their Spring 2022 campaign. 

* I haven't done this specific kind of thing before

Personally I was quite chuffed, this would be a great little project to do over a day. Early on it was difficult to fill my days with meaningful things, adjusting to my temporary new life in Germany. So I chose a nice warmish day that same week. It worked out well with my son at day care and my partner busy with work, so not to notice me make a fool of myself.

BEFORE: The Red Variety

BEFORE: Klar apfel (White Transparent)

The trees in question are two different varieties of apple, planted around 8 years ago. One is a red, late season unknow variety for eating. The other is an early "Klar Apfel" or White Transparent, being sweet and tart, much better for cooking. These trees were around 4.5-5m tall, so I would have to enlist the help of a ladder - Acrophobia be damned!

I do like a challenge, so after dropping my son off I got straight to work. Preparing myself, I took a few deep breaths, I paced around the trees. Armed with secateurs and loppers and a healthy dose of optimism I was ready, all these years of my partner talking up my horticultural skill to her parents it was my time to shine!

But before we see how I went, lets look at the theory behind why trees need maintenance pruning to manage productivity and longevity. The type of pruning you'll need will be based on the type/species of tree (fruiting or ornamental), it's age and position (park tree or street tree). In my case a fruiting trees can gets pruned fairly regularly. This can be annually or bi-annually, depending on species - as some fruit grows on new growth, some on older. The way it is maintained aims to produce a healthy tree that produces crop year after year (once mature enough).

Trees in parks are usually selected to be robust, long lived and provide shade for park goers, hopefully for many generations to come. Species/varieties are selected that may grow taller and broader, given that they will have more space to grow compared to orchard trees or those that line our streets. 

"Oh give me land, lots of land under 
starry skies above. Don't fence me in"

Park trees will generally have less maintenance after establishment, where the shape of the tree will require less uniformity. During the establishment phase, trees maybe under-pruned to avoid low branches so to enable recreational opportunity and will generally have a good root protection zone created to reduce the amount of pressure and soil compaction from foot traffic.

Street trees are a little different again. They generally need to be varieties that will live better in a modified environment. They will have to live along streets that may not allow adequate space to grow or at least have opportunity to retrofit hardscapes to allow more space. They will tend to be species that have naturally narrow habits or varieties chosen for this specific form (such as fastigiate varieties). 

An avenue of Plane Trees in Berlin

Trees selected for life along our streets will need to have not only an adequate or longer establishment period (a harsher environment) but also an ongoing maintenance period of at least one more growing season (>12 months). This will ensure tree branches can be lifted to an adequate clearance, not only for pedestrians but to create a clear eye line for motorists too.

Urban forestry infrastructure has come along way from digging a tree pit that may be 1m by 30cm and a metre deep for trees. This basically meant the tree was being potted up. We now have some fairly ingenious tree "vault" systems that allow not only adequate root growth but to also house services (electricity, water etc). 

These vaults aim to alleviate crowding without impeding growth. They may be expensive but when you compare it to the life long cost of maintenance and the possibility of failure it seems to be well worth the investment. The type of systems should be considered for every landscape project as it is easier (and cheaper) to have these installed at the start, again it all starts with planning.

Quercus robor Fastigiata - is an
upright, columnar form variety.

The main principles of tree pruning focus on maintenance and intervention. These principles emphasise reduction over removal. Trees obviously shouldn't be allowed to be removed without good reason, e.g. natural decline, pose a threat to property/person or storm damage. There should be adequate management from early on while in a nursery situation up until the end of the maintenance period, careful planning early on will go along way, not only to allow the tree to survive but to flourish. For this reason it is imperative that tree managers involve reputable nurseries that grow to specific tree standards, to help the success of their projects.

So what are the basics of tree maintenance? It's fairly straight forward but putting the time in early is the key. Firstly you want to undertake an overall assessment of the tree. Its physical appearance in relation to the environment around it as you may not be able to correct one without managing the other.

Generally the actions that need to be taken when pruning any tree will be:

* remove or reduce damaged or dead branches/limbs

* reduce or remove competing branching

* intervention to branches that are at angles greater than 45 degrees i.e. growing back towards the trunk

* reduce branch interaction, that is remove any branches that "cross paths"

* open the habitat to allow better air flow and reduce pest and disease occurrence 

* remove suckering stems in the case of grafted varieties

A general guide to pruning

For more specific projects, e.g. involving government agencies, the trees required may be subject to inspection and reporting, looking at some of the following points:

* free from pests and disease

* have adequate and uniform branching/symmetry 

* correct root crown depth (the position of planting in relation to where the trunk meets the roots)

* adequate stem taper (broader at the bottom, getting smaller towards the top)

* apical dominance (a single or dominant growing tip in place)

* self supporting (without the aid of stakes)

* Adequate root development such as root ball occupancy (container specimens) absence of root 

  issues such as "J" roots, girdling or being "pot" bound

The above points are principles good nurseries will incorporate into their best practice for tree production. If you can source a tree that has been given the best start, the chances of establishment and longer term success are increased. Best practice principles have been around for sometime not just in Australia but worldwide. 

In recent years Australia has adopted the Tree Stock Standard for Landscape Use (AS 2303:2018). The objective here is to provide a framework of criteria for not only those who grow trees but the planners, specifiers and end consumers. You can find more info here.

So how did I go you ask? For my first time undertaking pruning of fruit trees I think I did pretty well. Given the slightly late timing of the prune and the two different types of apples, I think the results as of today are as were expected. 

AFTER: The Red Apple Variety 

AFTER: The Klar apfel

The red variety has sprung back into leaf very nicely. Given it is a late season apple I wasn't expecting it to flower strongly, instead it has put it's energy into new growth. I am also not expecting it to produce  much fruit this season and I will recommend it gets thinned out again next winter, possibly taking the top out also to aid in better harvesting.

The Red Variety 12/05/2022

The Klar apfel 12/05/2022

The Klar apfel flowered pretty strongly after pruning, it has some small fruit developing, but given the amount of wood I removed, the yield will be significantly less this season. It has struggled putting on foliage so far, but given it's type I assume this will occur as the fruit matures. This one shouldn't be thinned out again for a few seasons, to allow more fruiting wood, but I will also recommend the top is reduced to help the ease of harvest in future seasons.

The Klar apfel 26.05.2022

The Red Variety 26.05.2022

So there you are, I had a go and I think you can too. I have always thought many areas of plant growing and management can be a bit of an educated trial and error process. As long as you get something out of it, learning, recreation or enjoyment for example, that's the main thing.

Don't be scared to try, if you are worried there is HEAPS of info online, plenty of YouTube tutorial videos and if you are visiting your local nursery ask the horticulturalist on duty, if they are anything like me they'll enjoy a chat about plants. Good luck!