Sweet potato

When to plant/sow in zone:

Requirements: Warm, frost-free conditions; full sun to part shade; well-drained position.

Soil: Loose, well-drained soil enriched with compost and/or well-rotted manure or organic pellets.

How to start: TUBER: Lay an entire healthy tuber horizontally in a pot filled with potting mix, covering the tuber. In 3-4 weeks, it will produce shoots. Once shoots are 15-20cm, cut them off the tuber. Remove the lower leaves, and plant them in the ground in a 7-10cm deep hole, ensuring at least one leaf node is buried. Space cuttings 25-30cm apart, in rows 60cm apart. Water them and mulch with straw.

How to grow: Water whenever soil feels on the dry side. Mulch with straw at the growing point. Apply seaweed solution monthly. Apply organic fertiliser pellets every two months. Trim vines if required.

When to harvest: Start harvesting from about 17 weeks, depending on the climate. To locate the tubers, look for thicker stems at ground level then gently loosen the surrounding soil with a garden fork to lift the tubers. Harvest a few larger tubers as needed, leaving the rest to mature further.

Troubleshooting: Rotting tubers; wilt