The Sweet Potato is not at all related to the common potato, its more of a tropical ground cover with large tubers that prefer growing in warmer climates and a wet summer. There are many different varieties with red, purple and orange skin and either orange or white flesh. I love the white-fleshed purpled skinned variety, it is nutty and creamy and unbelievably good roasted in the coals. The orange fleshed on is almost as sweet as pumpkin when cooked, beautiful mashed or in soups.
Sweet potato is named Ipomea batatas and is best to plant out in Perth around October when the soil temperature is warmer. It’s a long term crop and won’t be ready to be harvested until April.
The most important factor to remember is to grow your sweet potatoes from the cuttings, not the tuber. Cut a length of cutting 30cm long, remove all the lower leaves, plant it out horizontally just below the soil, leaving only the top two leaves exposed.
I recommend rock dust and slow release fertiliser for sweet potatoes, if they get too much nitrogen you will end up with a mass of leaves and vine, but tiny tubers. Potassium and low levels of phosphorus is ideal. Up north you can grow sweet potato all year round, but I suggest you move the crop every few years so pests don’t arrive to decimate your crop.
Don’t get the edible sweet potato mixed up with the ornamental sweet potato that has either lime green or burgundy leaves. Beautiful in the garden and in pots, but need a lot of summer watering.