Tom Hart Dyke, plant hunter and world gardener, Lullingstone Castle, Kent

In the shelter of a Victorian walled garden, we laid out the world garden

My garden had traumatic beginners. It's 15 years since my friend Paul and I went on an ill-advised orchid-hunting trip in Colombia. We were captured by guerrillas, and held hostage in the jungle for nine terrifying months. In June 2000, three months into our ordeal, an AK47 was thrust into our faces, and we were told to prepare to die that night. So how would you spend your last precious hours on earth? I lost myself in designing my dream garden - a "world garden" containing all the plants I had collected from across the globe, planted out in their countries of origin.

It took another five years for that dream to become a reality, back at my family home of Lullingstone Castle in Kent. I've been gardening since I was three, encouraged by my inspirational granny. I've always been fascinated by where plants come from: over 80% of our garden plants come from abroad, and there's no better way of understanding how to care for them than to see them in their native habitat. In the shelter of a Victorian walled garden, we laid out the world garden - one acre arranged as a map of the world, the other acre with a nursery to grow some of the treasures that wouldn't survive outside.

It's been thrilling watching the garden mature, and this year the autumn color has been sensational. Last winter was mild and sunny, enabling tender shrubs such as lemon verbena and fuchsias to develop a woody structure early, so they've been flowering since June. Cacti that usually flower in May and June have been in bloom from April to November. Eucalyptus flowered first in May, and again in autumn, fooled into thinking it's the start of the southern hemisphere spring.

There are nearly 8,000 plants in the garden, some spooky. Puya raimondii is the tallest of the puyas, "mammal-eating" plants from South America (its spiny leaves trap animals, which die, then decay, providing fertiliser), but I'm prouder of P.retrorsa, with a 13ft spike of turquoise flowers, grown from seed I collected from the slopes of the volcano Cotopaxi.

My favorite spot

"Mexico" in early autumn is ablaze with color from salvias, penstemons and amazing dahlias, including D.excelsa, the tallest dahlia in the world. Then there is the fleshy drama of yuccas, echeverias, dasylirion and prickly pears. It will soon be covered to keep off the winter wet, so I treasure every day till then.