How to grow sweet potatoes : instructions for growing sweet potatoes. From planting to harvest.A detailed guide that will explain the stages of growing the American potato with tips to adapt this cultivar to Italian latitudes.
Autumn is the ideal time to set aside sweet potatoes to produce plants for growing in the garden.
American potato or sweet potato, the plant
The American potato , also called sweet potato or batata , is the botanical species Ipomoea batatas , belonging to the Convolvulaceae family.
Its large, fleshy, tuberous roots have a sweetish flavour and for this reason they soon acquired the nickname sweet potatoes .
From a botanical point of view, the American potato has little in common with our classic potato (Solanum tuberosum) with which it does not even share the same family (that of the Solanaceae for our local potatoes). The plant is also different.
Depending on the variety, sweet potatoes can have different colored flesh and skin: we are therefore talking about red, orange or yellow flesh sweet potatoes as shown in the photo below.
Ipomoea batatas is a plant native to the tropical areas of the Americas. Due to the beauty of its flowers, some varieties of sweet potato are grown for ornamental purposes. Due to its origins, it is important to underline that the sweet potato does not tolerate the cold, for this reason in Italy it is treated as a plant for late spring or summer cultivation.
To give the best, sweet potatoes should be grown in environments with average temperatures of 24 °C and with sunny exposure. Sweet potatoes are sensitive to drought while an excess of water can cause rot or “breakage” of the tubers.
Depending on growing conditions, sweet potatoes take 2 to 9 months from planting to harvest.
How to Plant American Potatoes
The sweet potato is not grown like our potatoes. In Italy it is not possible to grow the sweet potato from seed because, with our climate, it is unlikely that it will produce flowers.
To grow potatoes , we Italians are used to starting from the tuber but even this technique is not recommended for growing sweet potatoes because you would run into the rotting of the tubers which, compared to our potatoes, are more perishable. So, who wants to grow sweet potatoes , what should they do?
It will have to start from special herbaceous cuttings that it can easily self-produce.
How to Grow Sweet Potatoes
To grow sweet potatoes you will need to start from herbaceous cuttings: two sweet potatoes will be enough to produce cuttings in quantities sufficient to cultivate 10 square meters of vegetable garden.
Between October and November, buy some tubers of American potatoes derived from organic farming. Store the tubers in environments where the temperature never falls below 15 °C, low temperatures could cause irreparable damage.
Starting from the beginning of March, you can prepare your herbaceous cuttings: place each tuber in a 14-15 cm diameter pot filled with seedling soil (very soft and rich in organic matter), leaving about 1/3 of the tuber above the ground.
Place the pots in a very bright environment where the temperature never drops below 12-15 °C, not even at night. Those who work in a domestic environment could place the two pots between the space of a double window, perhaps near a radiator, in these circumstances you will have to be careful to always keep the soil moist.
Warning: humid but not wet!
Once the tubers have produced 15 cm shoots, gradually move the pots outdoors so that the shoots can adapt to outside temperatures.
It is advisable to grow sweet potatoes in open fields only when outside temperatures do not fall below 14 °C at night, while during the day the temperature should be at least 21 °C. In short, those who live in Northern Italy will have to wait until the end of May to grow sweet potatoes, while those who live in the South can anticipate based on the seasonal climate trend.
When the shoots have reached at least 15 cm and with 5-6 leaves, if the temperatures allow it, you will have to detach them from the tubers and plant them in the soil that you have previously worked (with a digging of 25-30 cm). The planting of the shoots should be done at a distance of 70-80 cm between the rows and 40-50 cm on the same row.
If the soil has already been cultivated, it will not be necessary to proceed with new fertilization. Follow the cultivation with very moderate irrigation. Irrigate at the time of planting and pay more attention to irrigation in the first two weeks after planting. Then it will be sufficient to irrigate only in long periods of drought. You can harvest sweet potatoes from the end of September to mid-October.
