Why Chitting Potato Sprouts is Key
Encouraging your seed potatoes to sprout, a process known as chitting, is a fundamental step for many gardeners aiming for an earlier and more vigorous start to the growing season. This technique involves providing the right conditions for the potato's eyes to develop short, sturdy sprouts before planting them in the soil or growing bags. Success here lays the groundwork for healthy potato plants blooming and ultimately, a better harvest, preventing common issues that can arise from planting unprepared tubers.
The primary benefit of chitting is that it gives your potato plants a head start. By the time the seed potato is planted, it already has developing shoots. This means the plant can begin drawing nutrients and growing leaves sooner, often leading to earlier harvests and potentially larger yields. It also allows you to inspect your seed potatoes for disease or damage before you commit them to the ground, saving you time and effort later on.
For those wondering about growing potatoes in pots or growing bags, chitting is particularly beneficial. These containers offer a more controlled environment, and starting with pre-sprouted tubers can ensure your plants establish themselves quickly and effectively, maximising the use of limited space.
Mistake 1: Insufficient Light During Chitting
One of the most frequent errors is attempting to chit potatoes in complete darkness. While potatoes need warmth to start sprouting, they require light to develop strong, short, green or purplish sprouts. If kept in the dark, the sprouts will become long, thin, and white or pale yellow, making them weak and prone to breaking off during planting. This reduces the plant's initial vigour and can delay its development significantly.
Mistake 2: Overcrowding the Seed Potatoes
Another common oversight is packing too many seed potatoes into one tray or container. Potatoes need adequate space and air circulation to prevent the development of mould and disease. Overcrowding not only encourages rot but also means that the limited light and air are not distributed evenly, leading to uneven sprouting and weaker growth overall. It's essential to give each seed potato enough room to breathe and receive light.
Chitting is about nurturing potential, not just waiting for growth.
The Correct Method for Growing Potato Sprouts
Achieving robust potato sprouts is straightforward when you follow a few key principles. The aim is to provide a cool, bright environment that encourages the development of short, sturdy sprouts, often referred to as 'chits'. This preparation phase is vital for how to grow a potato plant that thrives from the outset.
Setting Up Your Chitting Station
Begin by selecting certified seed potatoes. These are specifically grown for planting and are less likely to carry diseases. Place them, 'rose end' (where most of the 'eyes' or buds are) upwards, in a single layer in shallow trays, egg boxes, or even old fruit punnets. Avoid stacking them directly on top of each other; a shallow tray is ideal to ensure light reaches all sides.
Environmental Conditions for Chitting
Locate your trays in a cool, frost-free place that receives plenty of indirect natural light. An unheated room, a porch, or even a bright windowsill (away from direct, scorching sun) are suitable. The ideal temperature range for chitting is between 7°C and 15°C. Too much heat can encourage rapid, weak growth, while temperatures below 7°C may slow the process down considerably or even damage the developing sprouts.
Monitoring and Care
Check your potatoes regularly. Within a few weeks, you should start to see small, stubby sprouts emerging from the eyes. If you notice any signs of mould or rot, remove the affected potato immediately to prevent it from spreading. Ensure good air circulation around the tubers. If the sprouts begin to look leggy and pale, it usually indicates insufficient light, so move them to a brighter spot.
Inspect your seed potatoes thoroughly before chitting. Discard any showing signs of soft rot, blight, or extensive bruising, as these can compromise the entire batch.
Mistake 3: Planting Too Early or Too Late
Timing is critical when it comes to planting your chitted seed potatoes. Planting too early, before the risk of hard frost has passed and the soil has warmed sufficiently (generally above 7°C), can shock the young sprouts and severely stunt growth. Conversely, waiting too long after the sprouts have developed can lead to them becoming too long and brittle, increasing the risk of damage during planting. Aim to plant when the sprouts are about 1.5-2.5 cm long and sturdy.
When to Plant and What to Expect
Understanding when to plant your chitted potatoes is as important as the chitting process itself. This decision is influenced by your local climate and the specific potato variety you are growing. For most regions, the optimal time to plant potatoes outdoors is after the last frost, typically from mid-spring onwards.
Soil Preparation is Crucial
Before you even think about planting, ensure your soil is well-prepared. Potatoes thrive in loose, well-drained soil rich in organic matter. Dig in compost or well-rotted manure to improve fertility and structure. If you are growing potatoes in pots or growing bags, use a good quality, peat-free compost mixed with some multipurpose compost to provide adequate drainage and nutrients.
Planting Techniques
When planting, handle the chitted seed potatoes carefully to avoid snapping off the delicate sprouts. Dig trenches about 10-15 cm deep, or place them in your containers. Place the seed potatoes in the trench or container with the sprouts facing upwards, spaced about 30-40 cm apart. Cover them gently with soil or compost, leaving about 5-7 cm of soil over the top. As the potato plants grow, you will need to 'earth up' – drawing soil around the stems to protect the developing tubers from sunlight and encourage more tuber formation.
What to Expect After Planting
Within two to four weeks of planting, you should start to see the first green shoots emerging from the soil. The speed of emergence depends on soil temperature and moisture levels. Once the plants are established, they will grow rapidly, producing foliage and eventually, if the variety is prone to it, potato plants blooming with characteristic flowers. This is a good indicator that tubers are forming underground.
The 'earthing up' process is not just about covering the tubers; it's about providing support and maximising yield.
Mistake 4: Forgetting to 'Earth Up'
A significant mistake for new gardeners is neglecting to 'earth up' the potato plants. As the stems grow, tubers form on the underground stems. If these tubers are exposed to sunlight, they will turn green and produce solanine, a toxic compound that makes them inedible and bitter. Earthing up involves drawing soil or compost up around the base of the plant, covering the developing tubers. This process should be repeated as the plant grows, usually two to three times, until the foliage is well-developed.
Alternative Approaches and Troubleshooting
While the standard method of chitting and planting is highly effective, understanding alternative approaches and how to troubleshoot common issues can further enhance your success in growing potatoes.
Early Sprouting Without Full Chitting
Some gardeners prefer not to fully 'chit' their potatoes but simply warm them slightly indoors for a week or two before planting. This encourages a very basic awakening of the eyes without developing long sprouts, which can be useful if you are concerned about sprout damage during planting or have limited space for chitting trays. However, this method may result in a slightly later start compared to full chitting.
Growing Potatoes in Specific Containers
For those with limited garden space, growing potatoes in pots, sacks, or specialized potato grow bags is a popular alternative. The principles of chitting remain the same. Ensure your containers are large enough (at least 30-40 cm in diameter and depth for a single plant) and have ample drainage holes. The 'earthing up' process is adapted by simply adding more compost to the container as the plant grows, rather than drawing soil around the stems.
Troubleshooting Common Problems
If your potatoes fail to sprout, check the seed potatoes for signs of rot or disease. Ensure they are stored in a suitable temperature and light environment. If sprouts are weak or spindly, insufficient light is the usual culprit. If you see greening on tubers after planting, it's a clear sign that you need to 'earth up' more diligently. Pests like slugs and aphids can also be an issue; inspect your plants regularly and take appropriate action, such as using organic pest control methods or barriers.
Consider planting a mix of early, second early, and maincrop potato varieties. This staggering of planting times and harvest dates ensures a continuous supply and spreads the workload.
The key to troubleshooting is observation; regular checks reveal problems early.
When to Harvest Your Potato Crop
Knowing when to harvest your potatoes is the satisfying culmination of the growing process. The exact timing depends on the variety you've planted and the conditions it has experienced, but general indicators can help you decide. Harvesting too early can mean smaller tubers, while leaving them too long might risk spoilage or pest damage.
Understanding Potato Maturity
Potato varieties are typically categorised as 'early', 'second early', or 'maincrop'. Early varieties are usually ready for harvest around 10-12 weeks after planting, while maincrop varieties may take 20-25 weeks. The first sign that your potatoes might be nearing maturity is when the foliage and flowers begin to die back and wither. This natural process indicates that the plant has finished its growth cycle and is directing its energy into tuber development.
Testing for Readiness
To check if your potatoes are ready, carefully dig around the base of a few plants with your hands or a small trowel. For new potatoes (which are typically from early varieties), you can often harvest them when the plant is still green and flowering. Gently scrape away the soil from a few tubers to assess their size and skin texture. New potatoes have thin, delicate skins that rub off easily. Larger, mature potatoes will have thicker, more robust skins that are harder to peel off by hand.
Harvesting Techniques
Once you've determined that your potatoes are ready, harvest them on a dry day if possible. This helps the skins to dry and harden, which improves their storage life. Carefully dig around the plants with a garden fork or spade, lifting them from the soil. Be cautious not to damage the tubers with the fork or spade, as any cuts or bruises can lead to rot during storage. Gently brush off excess soil; do not wash them unless you plan to use them immediately.
Dry storage conditions are paramount for keeping harvested potatoes fresh for extended periods.
Storing Your Harvest
After harvesting and allowing them to dry thoroughly, store your potatoes in a cool, dark, and well-ventilated place. Avoid storing them in plastic bags, which can trap moisture. Hessian sacks, paper bags, or shallow crates are ideal. Keep them away from onions, as the gases they emit can cause potatoes to sprout prematurely. Properly stored potatoes can last for several months, providing a delicious supply throughout the autumn and winter.