Thanks for your reply.
Under the law of adverse possession, a party can apply to the Land Registry for "possessory title" of land which they do not belong, provided that they have possessed the land, to the exclusion of the true owner, for a period of at least 12 years.
An application, setting out the facts, is submitted to the Land Registry, and if they are content that there has been "possession", their Surveyor will attend the site to verify matters.
In order to be successful, therefore, I am afraid you have to show more than the fact that you have just been "tending/maintaining the land"- normally, the Land Registry will only grant possessory title if you have incorporated the land into your own garden/or fenced in the land, preventing anyone else from physically being able to access it.
I therefore fear that you will have a long wait-12 years- before you can make an application, provided you go ahead and fence in the land now.
Sorry this is not the answer you were looking for, but it sets out the legal position.