What is Chitting Potatoes?
Chitting potatoes is the process of encouraging seed potatoes to sprout before planting them into the ground or containers. This practice, also known as 'pre-sprouting', involves placing seed potatoes in a light, cool environment for a few weeks. The aim is to develop short, sturdy, green or purplish shoots, known as 'chits', from the 'eyes' of the potato. This head start can significantly influence the speed at which your potato plants establish and, consequently, how early you can expect your first harvest.
- Purpose: To stimulate early, vigorous growth in seed potatoes.
- Outcome: Development of short, robust sprouts from the potato's eyes.
- Benefit: Faster crop establishment and an earlier harvest.
This method is particularly beneficial in cooler climates, such as the UK, where the growing season can be shorter. By giving the potatoes this initial boost, you are essentially fast-tracking their development, allowing them to be more resilient and productive once planted. It’s a straightforward horticultural technique that requires minimal equipment but yields substantial rewards for the home grower. Understanding the 'why' behind chitting helps in appreciating its value for successful potato cultivation.
Why Bother Chitting Potatoes?
The primary advantage of chitting potatoes lies in accelerating the growth cycle. When you plant a dormant seed potato, it needs to expend energy first to wake up and then to produce shoots. Chitting bypasses much of this initial delay. By the time you plant, the potato has already invested energy into developing viable sprouts. This means the plant can dedicate more of its resources immediately to root development and leaf growth once in the soil. For gardeners aiming for an earlier crop, especially first early varieties, this makes a tangible difference in the timeline from planting to harvest.
Furthermore, chitting allows you to inspect your seed potatoes. You can discard any that show signs of disease or rot, ensuring you're planting only healthy stock. Healthy seed potatoes are fundamental to a successful potato crop, preventing the introduction of pathogens into your soil. The stronger initial growth also means the young plants are better equipped to withstand early pest attacks or adverse weather conditions. It’s about giving your potato plants the strongest possible foundation, setting them up for a more robust and productive life cycle.
How to Chit Potatoes: The Basics
Preparing seed potatoes for chitting is straightforward and requires just a few key elements: the right kind of potatoes, a suitable container, and an appropriate environment. You'll need seed potatoes specifically intended for planting; these are different from regular supermarket potatoes, which may have been treated to prevent sprouting. Look for certified 'seed potatoes' from garden centres or reputable suppliers. These are usually sold in bags of varying sizes, from small first earlies to larger maincrop varieties.
Selecting Your Seed Potatoes
When choosing seed potatoes for chitting, consider the variety and its intended harvest time. First earlies (like 'Swift' or 'Charlotte') are ideal for chitting as they mature quickly. Second earlies offer a good balance, while maincrops benefit less dramatically but still appreciate the head start. Ensure the potatoes are firm, free from blemishes, and have visible 'eyes' where the sprouts will emerge. Smaller seed potatoes are often preferred for chitting as they tend to produce more shoots overall, leading to a bushier plant.
The Chitting Environment
The ideal location for chitting is a cool, frost-free spot that receives indirect natural light. A bright windowsill, a cool conservatory, or an unheated shed or greenhouse are often perfect. The temperature should ideally be between 10-15°C (50-60°F). Avoid direct, hot sunlight, which can scorch the developing sprouts, and completely dark conditions, which can lead to long, pale, 'leggy' shoots that are weak and easily damaged. These weak shoots are not ideal for planting and may need to be rubbed off.
Use shallow trays, egg boxes, or old seed trays to hold the potatoes. Arrange them in a single layer with the 'rose end' (the end with the most eyes) pointing upwards. This encourages the sprouts to grow upwards and outwards, forming sturdy chits rather than long, sprawling ones. If using egg boxes, the individual compartments are perfect for keeping potatoes separated and oriented correctly. Ensure there is good air circulation around the potatoes to prevent moisture build-up, which can lead to rot.
Tip: Place your trays in a location where they won't be disturbed and where temperature fluctuations are minimal. Consistent conditions are key to developing strong, healthy sprouts.
The Chitting Process
Over two to four weeks, you should start to see small, stubby sprouts emerging from the eyes. The ideal chits are short, thick, and often tinged with purple or green, indicating they have been exposed to light. If the sprouts are very long and white, the conditions are likely too dark or too warm. If this happens, you can often rub off these weak sprouts and allow stronger ones to develop under better conditions, or proceed with planting but accept a slightly delayed start.
The success of chitting lies in balancing light, temperature, and air circulation to encourage robust sprout development, not just rapid growth.
Once the chits are about 1-2.5cm (0.5-1 inch) long, the potatoes are ready for planting. Some growers advocate for 'bagging' the sprouted potatoes for a few days in a slightly warmer, darker environment just before planting to encourage the chits to swell and become more fleshy, but this is an optional extra step. The main goal is well-developed, sturdy sprouts.
Beyond Chitting: Planting and Alternatives
Once your potatoes are chitted, the next logical step is planting them. This typically occurs after the last frost, with timing varying by region. In the UK, this usually means from March for early varieties in milder areas, through to April and May for maincrop varieties. Prepare your soil or growing containers by digging in compost and ensuring good drainage. Plant the chitted seed potatoes about 10-15cm (4-6 inches) deep, with the sprouts pointing upwards, spacing them according to the variety’s recommendations (usually 30-45cm apart).
Planting Chitted Potatoes
When planting, especially in colder soils, some gardeners prefer to plant the chitted potatoes under a protective cloche or fleece for the first couple of weeks. This offers a little extra warmth and protection against late frosts, helping the young potato plants to establish more quickly. As the plants grow, you'll need to 'earth up' – draw soil around the stems – to protect the developing tubers from sunlight, which can turn them green and inedible. This process is repeated as the plants grow taller.
Chitting Potatoes UK Considerations: For those in the UK, the weather is a significant factor. The traditional planting times are based on avoiding the worst of winter frosts and maximising the length of the growing season. Chitting helps to make the most of this often-temperate climate, giving you a better chance of a good yield. The term 'seed potatoes' is standard, and the practice of chitting is widely adopted by gardeners across the country.
Growing Potatoes in Pots or Growing Bags: Chitting is also beneficial when growing potatoes in containers, such as growing bags for potatoes or large pots. The principles remain the same, but you have more control over the environment. Starting with chitted potatoes ensures that even in a restricted space, the plants get a strong start and begin producing tubers efficiently. Ensure your containers are deep enough to allow for earthing up as the plants grow.
What if You Don't Chit?
While chitting offers significant advantages, it's not strictly mandatory for growing potatoes. You can plant un-chitted seed potatoes directly into the ground. The main difference will be a delay in the emergence of the potato plants from the soil and a subsequent delay in the harvest. For gardeners who are less concerned about obtaining the earliest possible crop or who have limited time or space for the pre-sprouting process, planting directly is a perfectly viable option. The eventual yield may be similar, but the timeline is extended.
Alternatives to Chitting: Some gardeners might experiment with other methods, such as soaking seed potatoes briefly in warm water to encourage sprouting, or placing them in a slightly warmer environment than usual for a few days. However, these are less common and can sometimes lead to rot if not managed carefully. The established method of chitting in light, cool conditions remains the most reliable and widely recommended approach for gardeners seeking to optimise their potato harvest.
The 'Chitless' Approach: For those who choose not to chit, simply plant the seed potatoes directly when the soil temperature is suitable (around 8°C or 46°F). They will still sprout and grow, but it will take longer for the shoots to appear above ground. This approach is often taken by commercial growers who prioritise efficiency and may have specialised planting equipment, or by hobby gardeners who prefer a more 'hands-off' approach to their planting preparation.
Ultimately, the decision to chit or not depends on your priorities. If an earlier harvest and stronger initial plant growth are important, then the effort of chitting is well worth it. If convenience and simplicity are paramount, planting un-chitted seed potatoes will still result in a crop, just perhaps a slightly later one.