Habitat
Horseradish is a very easily grown plant, horseradish prefers deep moist well-drained soil in good sunlight. the plants require good soil if they are to produce good roots, though once grown they are very tolerant of environmental forces and continue to produce a crop for years. Horseradish does not thrive if it’s in the shade of trees. Some say that Horseradish prefers a wet clay soil, while others say that it will not grow in wet clay. The plant tolerates a pH in the range 5.8 to 8.3. If the roots are given some protection they will produce leaves through the winter, putting them into a greenhouse for this period is the easiest method. Horseradish can be a very invasive plant, it is considered to be a weed in some areas. Even small sections of root will regrow if they are left in the soil, making horseradish tough to get rid of when it becomes invasive.
The plant is said to have originated in Eastern Europe and West Asia, but as you can see is is grown over almost all of Europe.
USDA,
NRCS. 2009. The PLANTS Database (http://plants.usda.gov, 24 June
2009). National Plant Data Center, Baton Rouge, LA 70874-4490 USA.
Here in North America, Horseradish grows nearly everywhere besides for some of the desert-like areas of the south-west, south-eastern areas occupied with other crops, and the most northern provinces of Canada
USDA,
NRCS. 2009. The PLANTS Database (http://plants.usda.gov, 24 June
2009). National Plant Data Center, Baton Rouge, LA 70874-4490 USA.
Essentially. Horseradish is a tough root that can grow almost anywhere. It does not necessarily have an ecological niche besides for "in the ground with moist soil and sunlight".
The town of Collinsville IL is one of the many towns that harvest lots of Horseradish root. In fact, they even have an annual festival. see more at International Horseradish Festival,