I grow a wide range of South African bulbs, about 800 species in all, on a garden just 17 m x 15 m, and thats not miles. To this I garden by the inch and not by the yard or acre. See my website
It is a wide range but I concentrate on growing Crocosmia, Chasmanthe and Tulbaghia, and I once held the UK National Collections of these. I am also a very passionate grower of Kniphofia, Eucomis, Amaryllis (belladonnas), Crinum and Freesia laxa (Anomatheca), which I breed and have produced a range of pinks and lilacs. I also grow both colvillei and nanus Gladioli.
My aim with many species is to grow them successfully in the UK climate and get the best display from my garden, which I open for charity from June to September for National Charities. Here in the south-west of the UK we have a warmer climate and we are wetter but our specific problem is that we can have -5 °C by night and 18 °C by day and within just 12 hours, if you add rain and ice to the equation then it can be very detrimental to numerous species, especially those grown in pots. During some winters frost penetrates to about three inches so all but the hardiest bulbs have to be planted below 4 inches, indeed I plant Watsonias at 10 inches and have planted Crinum moorei at over two feet.
I have learnt to place the bulbs deeper than what many books describe and by talking to many South African bulb specialists, have found that bulbs in habitat are found very deep, and not because of the cold but because of predation, namely baboons; and of course the deeper you plant a bulb, the more stable the soil temperature, which is why mulches are so beneficial, whether they be organic, inorganic or living, and why I can get away with growing such a wide range of species here. I am also very fond of the word 'microhabitat' and completely believe that 'thought and placement' are the key words to successfully growing anything.