Costoluto Fiorentino is a heavily ribbed flat Italian tomato type from Florence, Italy. This very famous Italian heirloom we consider to be a (SD) semi determinant variety as the plant grows to 6ft tall and they should be staked and tied. The plant produces brilliant bright red medium to large, old-fashioned, heavily ribbed tomatoes. They can average between 12-16 oz). Costoluto Fiorentino is known for it's high heat tolerance.