English Oak in a small garden
I used to have a mighty old English Oak in my garden in Wokingham. It grew in the northern corner of the garden and gave shelter from summer heat or rain. When I had to move back to Germany I knew I would really miss it. But when I unpacked my garden pots and plants in Germany, I noticed that one little acorn had started sprouting in one of my flower pots. It must just have sneaked in. So I decided to let it grow. One year later it was still doing well, so I decided to plant it into my new garden in Dietzenbach near Frankfurt. The little tree is almost 5 ft now and I am starting to realize it might not have been such a good idea to plant it. Germany is different to the UK. There are a lot of rules and regulations for gardens and how far away from the neighbour border a tree should be planted. Even though the garden is not smaller than the one in UK, I am worried now that the tree will be too big in 20 years time.
So could anyone advise me how I can prune this plant in young years so it doesn't grow too tall? It sounds somehow cruel and I don't really like the idea of crippling it. But if I don't do anything now I might have to take it down one day.