What polyhouse size and cost is needed to start carnation cut flower farming?

Carnation is almost always grown under a naturally ventilated polyhouse, it does not do well in open field in the plains. A common starting unit is 1000 to 4000 square metres. Polyhouse erection cost is broadly in the range of about Rs 700 to Rs 1100 per square metre for a good fan and pad or naturally ventilated structure, so a 1000 square metre house can run roughly Rs 7 to 11 lakh before planting material, drip and the crop. On top of that you need raised beds, drip with fertigation, and good quality planting material. NHB and state horticulture schemes give a subsidy on protected cultivation, often around 50 percent in many states but the slab, ceiling area and your eligibility change year to year and state to state, so confirm the current pattern and per square metre cost norm with your state horticulture office or NHB before you budget. Also line up a buyer or commission agent in a flower market like Pune or Bengaluru first, because carnation needs steady cold chain and grading to fetch the good rate.