Potato farming requires careful management from land preparation and planting to harvesting and storage. One of the most important crop management practices that farmers should not overlook is hilling or moulding.
Hilling, also known as moulding, involves heaping soil around the base of growing potato plants to form raised ridges. The practice is commonly carried out after the potato plants have emerged and may be repeated as the crop develops.
Although hilling may appear to be a simple task, it plays an important role in potato tuber development, weed control, drainage and crop protection. Properly moulded potatoes generally have better soil coverage, reducing the risk of exposed tubers and quality losses.
What is hilling in potato farming?
Hilling is the process of pulling or adding soil around the base of potato plants and forming a raised ridge along the planting row.
Potatoes produce underground stems called stolons, which can develop into tubers. Keeping enough loose soil around the plant provides an appropriate environment for these stolons and developing tubers.
Farmers can carry out hilling manually using hoes or other farm tools, while larger-scale growers may use ridging and cultivation equipment.
The objective is not simply to pile as much soil as possible around the plant. Hilling should create a stable ridge while maintaining enough loose, well-aerated soil for roots and tubers to develop.
1. Hilling protects potato tubers from sunlight
One of the main reasons for hilling potatoes is to keep developing tubers covered with soil.
Potato tubers exposed to sunlight can turn green because they produce chlorophyll. Green potatoes may also contain increased levels of glycoalkaloids, including solanine, which can make them unsuitable for consumption when present at high levels.
As potato plants grow, some tubers may move closer to the soil surface. Heavy rainfall or soil erosion can also expose them.
Regular hilling helps maintain adequate soil cover and reduces the risk of potatoes being exposed to sunlight. This is particularly important during the tuber development stage.
2. Hilling creates more space for tuber development
Potatoes need adequate soil around the plant to allow stolons and tubers to develop and expand.
A properly formed ridge provides additional soil volume where developing tubers can grow. This can help reduce crowding and improve the chances of producing well-shaped marketable potatoes.
However, farmers should ensure that the soil used for hilling is loose and not heavily compacted. Compacted soil can restrict root growth, reduce aeration and make it difficult for tubers to expand.
3. Moulding improves drainage
Water management is critical in potato production. Potatoes perform poorly in waterlogged soils because excessive moisture can reduce oxygen availability around the roots and create favourable conditions for some diseases and rotting problems.
Raised potato ridges help excess water move away from the root and tuber zone.
This is especially useful in areas that receive heavy rainfall. Good drainage can help prevent prolonged waterlogging and maintain healthier growing conditions.
However, hilling should be combined with proper field drainage. Ridges alone cannot solve serious drainage problems caused by poorly designed fields or heavy soil.
4. Hilling helps control weeds
Weeds compete with potato plants for water, nutrients, sunlight and growing space.
During the moulding process, young weeds growing between potato rows can be buried or disturbed. This can reduce weed competition, particularly when hilling is done while weeds are still small.
Controlling weeds early is important because heavily infested fields can experience reduced potato growth and lower yields.
Farmers should nevertheless combine hilling with other appropriate weed management methods where necessary.
5. Hilling protects developing tubers
Potato tubers are vulnerable to several forms of damage when they are close to the soil surface.
Adequate soil coverage provides a physical barrier that can reduce exposure to sunlight, temperature fluctuations and some pests. It can also help protect tubers from physical damage caused by farm operations.
Good moulding therefore contributes to maintaining better tuber quality throughout the growing season.
6. It supports healthy root and tuber growth
Potato roots and developing tubers require a favourable soil environment.
Well-formed ridges with loose, adequately aerated soil can provide better conditions for root growth and tuber development. When soil is excessively compacted, roots may struggle to penetrate the soil while tubers may develop poorly.
For this reason, hilling should be done carefully to avoid damaging potato stems, roots or developing tubers.
## When Should Potatoes Be Hilled?
**Timing is important when hilling potatoes.** Farmers should not wait until developing tubers are already exposed before taking action.
The first hilling is generally carried out after the plants have emerged and have developed enough foliage to withstand the operation. The exact timing depends on the potato variety, soil type, weather conditions and production system.
A second moulding may be necessary as plants continue growing, especially where the ridges have settled or been eroded by rainfall.
Farmers should monitor the crop regularly and maintain sufficient soil cover throughout tuber development.
If heavy rainfall washes soil away from the ridges, the ridges should be repaired to restore adequate tuber coverage.
What happens when potatoes are poorly hilled?
Poor hilling can leave potato tubers close to the soil surface or exposed. This increases the risk of greening and quality losses.
Inadequate soil volume can also limit the space available for tuber development, while poor ridge formation may contribute to drainage and weed management challenges.
However, excessive or poorly timed hilling can also damage plants. Farmers should therefore aim for proper ridge formation rather than simply adding large amounts of soil.
Hilling should be part of an integrated potato management strategy
While hilling is important, it cannot solve every potato production problem.
Farmers should combine good moulding practices with the use of quality certified seed, proper spacing, soil testing, balanced fertiliser application, crop rotation, good drainage and regular field scouting.
Pests and diseases should also be monitored throughout the growing season so that problems can be identified and managed early using appropriate integrated pest and disease management practices.
Hilling or moulding is a simple but essential practice in potato farming. By keeping developing tubers covered, creating adequate space for tuber growth, improving drainage and helping with weed management, proper hilling can contribute to healthier crops and better-quality potatoes.
Farmers should begin moulding at the appropriate stage of crop development and maintain good soil coverage as the plants grow. Ridges should also be repaired whenever heavy rainfall or erosion removes soil.
Ultimately, good hilling means better tuber protection, improved crop management and better potato quality.
How many times do you normally hill your potatoes during the growing season? Share your experience with other farmers.
Author: Moureen Koech
Moureen Koech is a passionate Digital Journalist, an adept Agribusiness Writer with a keen eye for news and an impactful story-teller,whose stories provide key value to Agripreneurs and stakeholders in the Agricultural sector
