Potatoes will grow very quickly under warm and moist conditions. When they are 10cm tall, the leafy shoots can be mounded around with soil to their full height, a process known as ‘earthing up’. Earthing up potatoes will increase the length of underground stems that will bear potatoes. This mounding can be repeated once or twice more at 2 – 3 week intervals to ensure the best crop, with the added benefit of smothering any competing weeds.
Growing potatoes in a bag? Monty explains how to earth them up:
Find out how to earth up potatoes, below.
You Will Need
- Potato plants
- Garden fork or spade
Loosen soil between the rows using a garden fork. Use a rake or spade to draw the soil into a ridge along the length of the row around the emerging stems of the potatoes. Leave a shallow trough along the row at the top of the ridge to channel any water down to the developing tubers.
When growing potatoes in large pots or sacks, the tubers will have been planted into 10cm of compost at the base of the container. As the shoots emerge, add more compost at regular intervals, 5cm at a time, until the container is almost full.
On light soil, mix in well-rotted garden or bagged compost to earth up the potato plants. This helps conserve moisture which swells the tubers.