The Nursery industry grew out of the market gardening that supplied London via Covent Garden. The Lea Valley was "natural" for this development. Within easy reach by horse drawn vehicles travelling by night, with "chain" horses stationed at places like Stamford Hill.
The alluvial soil that served market gardens of fruit growers was also level and suited the constructors of early "Vine" type glass houses. Water was available, boring wells was like putting a pin into a plastic pipe and, for example, ballast pits filled up as soon as they were abandoned.
Transport was well served by rail, road and canal. The main road, following roughly the Roman Ermine St. was the...
Source: Samuel South & Sons