The potato was introduced to Ireland as a garden crop of the gentry.
The potato was not popular at first;  however, after an unusual promotion campaign that was supported by landowners and members of royalty, who wanted their tenants to plant and eat the crop, it rose in popularity.
By the late 17th century, it had become widespread as a supplementary rather than a principal food; the main diet was still based on butter, milk, and grain products.
By 1800 to 1820, the potato became a staple of the poor, especially in winter.
Furthermore, a disproportionate share of the potatoes grown in Ireland were of a single variety, the Irish Lumper.

With the expansion of the economy between 1760 and 1815, the potato was increasingly adopted by the people and became a staple food year round for farmers.
The widespread dependency on this single crop, and the lack of genetic variability among the potato plants in Ireland and Europe (a monoculture), were two of the reasons why the emergence of Phytophthora infestans had such devastating effects in Ireland and in similar areas of Europe.

Potatoes were essential to the development of the cottier system; they supported an extremely cheap workforce, but at the cost of lower living standards.
For the labourer, "a potato wage" shaped the expanding agrarian economy.

The Celtic grazing lands of ... Ireland had been used to pasture cows for centuries.
The British colonised ... the Irish, transforming much of their countryside into an extended grazing land to raise cattle for a hungry consumer market at home ... The British taste for beef had a devastating impact on the impoverished and disenfranchised people of ... Ireland ... pushed off the best pasture land and forced to farm smaller plots of marginal land, the Irish turned to the potato, a crop that could be grown abundantly in less favorable soil.
Eventually, cows took over much of Ireland, leaving the native population virtually dependent on the potato for survival.

The potato was also used extensively as a fodder crop for livestock immediately prior to the famine.
Approximately 33% of production, amounting to 5,000,000 short tons (4,500,000 t), was normally used in this way.
The potato was introduced to Ireland as a garden crop of the gentry. The potato was not popular at first;  however, after an unusual promotion campaign that was supported by landowners and members of royalty, who wanted their tenants to plant and eat the crop, it rose in popularity. By the late 17th century, it had become widespread as a supplementary rather than a principal food; the main diet was still based on butter, milk, and grain products. By 1800 to 1820, the potato became a staple of the poor, especially in winter. Furthermore, a disproportionate share of the potatoes grown in Ireland were of a single variety, the Irish Lumper.
With the expansion of the economy between 1760 and 1815, the potato was increasingly adopted by the people and became a staple food year round for farmers. The widespread dependency on this single crop, and the lack of genetic variability among the potato plants in Ireland and Europe (a monoculture), were two of the reasons why the emergence of Phytophthora infestans had such devastating effects in Ireland and in similar areas of Europe.
Potatoes were essential to the development of the cottier system; they supported an extremely cheap workforce, but at the cost of lower living standards. For the labourer, "a potato wage" shaped the expanding agrarian economy.
The Celtic grazing lands of ... Ireland had been used to pasture cows for centuries. The British colonised ... the Irish, transforming much of their countryside into an extended grazing land to raise cattle for a hungry consumer market at home ... The British taste for beef had a devastating impact on the impoverished and disenfranchised people of ... Ireland ... pushed off the best pasture land and forced to farm smaller plots of marginal land, the Irish turned to the potato, a crop that could be grown abundantly in less favorable soil. Eventually, cows took over much of Ireland, leaving the native population virtually dependent on the potato for survival.
The potato was also used extensively as a fodder crop for livestock immediately prior to the famine. Approximately 33% of production, amounting to 5,000,000 short tons (4,500,000 t), was normally used in this way.
Great Famine (Ireland)