Turnips can be bought from Jade for 5 flowers after giving her the initial Hardy Turnips but before you have the General Store. After, they can only be bought from there. Can be sold in a Shipment Box, or eaten raw.
Yield[]
Every plant yields 1 turnips which sells for 60 G. Therefore 540 G can be obtained per harvest which means 420 G profit.
Assuming a 30 day season and that its replanted as soon as they are harvested, you can get 63 turnips in a season on the same plot. This gives you 3780 G when sold which means 2940 G profit. You need to buy 7 bags of seeds for that.
NPCs
Abii • Ashlee •Brandon •Candice •Cloe •Danieru •Fenn •Granny Katlin •Jade •Jakob •Jenni •Jim •Johan •Liara •Mayor Jeimmi •Tiberius •Tomas •Yulif •Harvest Goddess
Buildings
Animal Ranch •Cafe •Carpenter's Hut •Church •Clockmaker •Fishing Hole •Fishing Hut •General Store •Goddess Pond •Mining Hill •Mining Hut •Poultry Farm •The Blacksmith •Townhall
Crops
Beetroot Cabbage Carrot Corn Cucumber Eggplant Grass Green Pepper •Industrial Hemp Hardy Turnip Onion Pineapple Potato Pumpkin Spinach Strawberry Sweet Potato Tomato Turnip Watermelon Wheat
Animals
Chicken Cow Sheep Animal Fodder Animal Medicine Chicken Feed Chicken Treat Cow Treat Egg Feeding Tray Food Trough Incubator Milk Miracle Potion Nest Box Sheep Treat Treat Wool
Tools
Cooking