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"Excuse me, Sir" asked the controller of the baggage scanner at the airport as he viewed a large mass of something opaque, "What are you carrying in your luggage?" "Soil", I replied.  "What are you doing in Rwanda?" "I am the dendrologist for Victory." That tends to be a conversation stopper so he shrugged and went back to his screen. In fact, I had tree seedlings in bags of soil in my suitcase for reasons which I shall explain...

Some people will fly from London to LA for a Taylor Swift concert; others will fly across the planet to follow their sports hero or favourite team but as a tree-hugger I am always keen to travel to look at a tree I have never seen before, particularly when it is new to science...

When I started my tree project 20 years ago it was almost unheard of that an indigenous Kenyan would come and buy native trees. The combination of knowledge, increasing wealth and concern about the environment has meant that in recent years, more and more Kenyans come and buy seedlings of East African trees. A couple of months ago a man appeared looking for unusual tree species. His name was Michael Mwangi Muthee and he invited my assistant and me to visit his shamba in Karen

I was driving down to our rain-forest patch last week while still on a main road to Kisumu on the eastern shores of Lake Victoria, when I saw a large crowd on both sides of the road. I assumed it to be an accident but I saw no motor vehicle. I slowed, stopped the car, got out and spotted a small snake on the side of the road surrounded by an excitable crowd looking fearful and agitated. I walked straight...

I know we all live in an increasingly international world but the last ten days have been unusually so for the tree-planter. On my 75th...