When to Plant Early Potatoes: The Key to Early Harvests
The ideal time to plant early potatoes is generally from March to April in most parts of the UK, once the risk of hard frost has significantly diminished and the soil begins to warm up. Planting too early can expose vulnerable shoots to damaging frost, while planting too late can delay your harvest, meaning you miss out on those sought-after first new potatoes.
- Plant early potatoes from March to April.
- Ensure soil temperatures are at least 7°C.
- Protect young plants from late frosts.
- Chitting seed potatoes is a vital preparatory step.
This timing aims to balance the need for warmth with the avoidance of frost, which can set back growth considerably. Early varieties, often called 'first earlies' or 'second earlies', are bred for speed, producing smaller, tender tubers sooner than maincrop varieties. Their precise planting window is dictated by ambient conditions rather than a fixed calendar date, making understanding your local microclimate and soil state paramount.
Understanding Soil Temperature and Frost Risk
While March and April are the commonly cited months, the critical factor for when to plant early potatoes is soil temperature and the lingering threat of frost. Seed potatoes need a soil temperature of at least 7°C (45°F) to begin sprouting and growing effectively. Planting into colder, waterlogged soil can lead to tuber rot and poor germination. You can check soil temperature with a simple soil thermometer, ideally taking readings at planting depth (around 10-15 cm).
Late frosts can be a significant hazard. If frost is forecast after you have planted, especially if shoots have already emerged, covering the young plants with horticultural fleece or cloches can prevent damage. The aim is to give your seed potatoes a head start by planting them when conditions are favourable but not so early that they are vulnerable to the unpredictable nature of spring weather.
The Importance of Chitting Seed Potatoes
Before you even consider planting, the process of 'chitting' your seed potatoes is a fundamental step for early varieties. This involves encouraging the potatoes to sprout in a cool, bright, frost-free environment for several weeks before planting. Place seed potatoes in shallow trays, 'rose end' (where the sprouts emerge) upwards, in a well-lit, frost-free location, ideally around 10-15°C. This encourages short, sturdy, dark-green or purple sprouts, rather than long, pale, weak ones that are prone to breaking off.
Chitting not only provides a head start on growth, accelerating the time to harvest, but it also allows you to inspect your seed potatoes for disease before they go into the ground. Healthy, well-chitted seed potatoes are more robust and better equipped to establish quickly once planted, giving your early potato crop the best possible start.
Preparing Your Planting Site
The success of your early potato crop is heavily influenced by site preparation. Early potatoes prefer well-drained soil. If you are planting directly into the ground, dig the soil over deeply, breaking up any heavy clumps and removing stones and weeds. Incorporating well-rotted manure or compost in the autumn or early spring will enrich the soil and improve its structure, but avoid using fresh manure, as it can scorch the tubers.
For those with poor soil or limited space, growing bags for potatoes or containers are excellent alternatives. When growing potatoes in pots or bags, it's crucial to use a good quality compost mixed with some grit for drainage. The principles of soil temperature and frost protection still apply, regardless of your planting method.
Selecting the right moment based on soil warmth and frost risk is more critical than adhering strictly to a calendar date.
When planning your planting, consider the different types of early potatoes available. 'First earlies' mature in around 10-12 weeks, while 'second earlies' take a little longer, typically 12-14 weeks. This difference can be significant for timing your harvest, especially if you want a continuous supply of new potatoes throughout the summer.
Factors Influencing Your Planting Decision
Deciding exactly when to plant early potatoes involves more than just looking at the calendar. Several environmental and horticultural factors play a significant role in determining the optimal time for planting to maximise your chances of a successful early crop.
Regional Variations and Microclimates
The UK experiences diverse climatic conditions. What might be the perfect planting time in the milder south of England could be too early for colder, more exposed regions in Scotland or the north of England. A general guideline for when to plant early potatoes in the UK must account for these regional differences. In colder areas, gardeners might need to wait until late April or even early May, or consider using protective measures like cloches or polytunnels to create a warmer microclimate for their seed potatoes.
Even within a region, microclimates exist. A south-facing, sheltered garden bed will warm up faster than a north-facing, windswept one. Observing your specific garden’s conditions and how quickly it thaws and warms after winter can give you valuable clues. The presence of early spring flowers, like daffodils, can sometimes be a good indicator that the soil is warming sufficiently for planting.
The 'Chit' Stage and Seed Potato Health
The stage of development of your seed potatoes, after chitting, also influences your planting timing. If your seed potatoes have developed very long, leggy sprouts because they have been kept in a too-dark or too-warm environment, they may be more fragile. It might be better to plant them slightly later once the risk of severe frost has passed, or to handle them with extreme care during planting to minimise damage to the sprouts. Conversely, if they have short, sturdy sprouts, they are generally robust enough for earlier planting, provided the soil conditions are right.
When you are selecting seed potatoes, look for firm tubers free from soft spots or signs of disease. Healthy seed potatoes are essential for growing seed potatoes that will establish well. If you are buying seed potatoes from a retailer, check their quality before purchase. The condition of the seed potato itself is a direct indicator of its potential for growth.
Alternative Planting Methods and Their Impact
Your choice of planting method can influence when you plant and how you protect your crop. Traditional rows in the open ground are susceptible to frost. However, planting in specially designed growing bags for potatoes or large containers offers more control. These can be placed in a sheltered, sunny spot, and if a severe frost is predicted, they can even be moved temporarily to a greenhouse, porch, or shed for protection. This flexibility allows gardeners to plant a little earlier, knowing they have a fallback plan.
The earliest possible planting is not always the best; patience for the right soil conditions yields superior results.
When considering growing potatoes in pots or bags, remember that these containers can dry out more quickly than the open ground, so consistent watering is key, particularly as the potato plants start to mature and bloom. The soil in containers also warms up and cools down more rapidly than in the ground, so careful observation of weather patterns is still advised.
Your local climate's typical frost patterns should be the primary guide for when to plant early potatoes.
Understanding these contributing factors helps you move beyond a generic 'plant in spring' to a more informed decision tailored to your specific circumstances. This proactive approach ensures that your efforts translate into a successful yield of delicious early potatoes.
Planting Early Potatoes: Practical Steps
Once you've determined the optimal window for when to plant early potatoes, the next step is the planting process itself. This involves preparing the ground, placing the seed potatoes, and covering them correctly. Following these steps ensures your tubers are set up for strong growth and a timely harvest.
Preparing the Planting Medium
Whether planting in the ground, in growing bags, or in pots, the medium needs to be conducive to growth. For open ground, as mentioned, ensure the soil is well-dug and enriched. For growing bags or containers, a good quality, peat-free compost mixed with some well-rotted organic matter or perlite for drainage is ideal. Fill bags or pots to about two-thirds full initially, leaving space to 'earth up' as the plants grow.
The Planting Process
Dig trenches or individual planting holes about 10-15 cm deep. If planting multiple rows in the ground, spacing is important; aim for about 30-40 cm between seed potatoes and 50-60 cm between rows to allow for growth and ease of earthing up. Place each chitted seed potato into the trench or hole, sprout-side up. It is important to plant seed potatoes with the sprouts pointing upwards to encourage the shoots to grow towards the light.
Cover the seed potatoes with about 5-8 cm of soil. This initial layer of soil acts as insulation, protecting the developing tubers from light and frost. Over the next few weeks, as the plants grow taller and more shoots emerge, you will 'earth them up' by drawing more soil around the stems. This process, typically done twice, encourages more tubers to form along the buried stem and prevents any developing potatoes from being exposed to sunlight, which can turn them green and inedible.
Protecting Young Potato Plants
Even after planting, vigilance is key. If a late frost is forecast, especially when the first shoots are appearing above ground, covering the emerging plants is crucial. For rows in the ground, you can use cloches or cover them with horticultural fleece, ensuring it doesn't directly touch the foliage if frost is severe. For potatoes in pots or growing bags, moving them to a more sheltered location temporarily, such as a cold frame, porch, or unheated greenhouse, can save the young plants.
Tip: For early varieties, consider planting a few seed potatoes in pots indoors or in a greenhouse a few weeks before the main outdoor planting date. This offers an insurance policy against late frosts and can give you an even earlier crop.
Monitoring Growth and Anticipating Harvest
After planting and earthing up, the next stage is monitoring the potato plants' growth. You'll see leaves emerge, and eventually, the plants will flower. The blooming of potato plants is a signal that tubers are forming beneath the soil. For early potatoes, the first signs of flowering usually indicate that harvest is approaching, typically within a couple of weeks for 'first earlies' and slightly longer for 'second earlies'.
The practice of earthing up is vital for both tuber development and protection.
When you are ready to harvest, you can carefully dig around the base of the plant to check for developing tubers. Gently unearth a few to assess their size. If they are to your liking, you can begin harvesting. For a continuous supply, you can dig up only what you need, leaving the rest to grow larger.
Alternatives and Considerations for Early Potato Growing
While the traditional method of planting early potatoes in open ground is popular, various alternatives and considerations can enhance your growing experience and yield, particularly when timing is critical for when to plant early potatoes.
Growing Potatoes in Containers and Bags
Growing potatoes in pots, containers, or dedicated growing bags for potatoes offers significant advantages, especially for those with limited space, poor soil, or a desire for greater control over the growing environment. These methods allow you to place your crop in the sunniest, most sheltered part of your garden, maximising warmth and minimising frost risk. This can enable slightly earlier planting than might be advisable in open ground, as containers can be moved if frost threatens.
When growing potatoes in pots, ensure the container is deep enough (at least 30-40 cm deep) and has adequate drainage holes. Use a good quality compost, enriched with organic matter. As the plants grow, you will need to add more compost to the container to cover developing tubers, a process known as earthing up, which is crucial for maximising yield and quality.
Hailing from Pots: Early Harvests
Using pots or containers for your early potato crop means you can often start earlier than in the open ground. Provided the seed potatoes are chitted and the soil within the pot is warming, you might plant as early as late February or early March in milder areas, with a firm plan to move the pots if frost is imminent. This flexibility is a key benefit of container growing, directly addressing the timing challenges associated with when to plant early potatoes.
It's also worth noting that potatoes grown in containers can sometimes mature a little quicker due to the contained soil warming more efficiently. However, they also require more frequent watering and feeding, as nutrients can leach out of the compost more readily.
Choosing the Right Variety
The 'early' in early potatoes refers to their maturity period. 'First earlies' mature the quickest, typically within 10-12 weeks of planting. Varieties like 'Swift', 'Lady Christl', or 'Maris Bard' are good examples. 'Second earlies' take slightly longer, around 12-14 weeks, and include popular types such as 'Charlotte' or 'Kestrel'.
When deciding when to plant early potatoes, understanding the specific variety's maturity time is helpful. If you want the absolute earliest possible crop, select a 'first early' variety. If you have a slightly later planting window or prefer to stagger your harvests, a 'second early' might be more suitable. Some gardeners plant both types at the same time to extend the period during which they have new potatoes available.
Intercropping and Companion Planting
For those looking to maximise space, intercropping can be an option. While potatoes are growing, their foliage does not cover the ground densely, leaving space for fast-growing, shallow-rooted crops that mature quickly. Radishes or spinach are often suggested as companion plants for potatoes, as they can be harvested before the potato plants require all the available space and nutrients. This approach requires careful planning to ensure the companion plants do not compete excessively with the main potato crop.
Tip: Avoid planting potatoes immediately after other solanaceous crops like tomatoes or aubergines in the same soil, as they can share soil-borne diseases. Rotating your planting site yearly is a sound practice for maintaining soil health and preventing disease build-up.
The goal is to achieve a balance between early planting and protecting tender growth.
By exploring these alternatives and keeping these considerations in mind, gardeners can make informed decisions about when to plant early potatoes, ensuring a successful and rewarding harvest tailored to their specific gardening conditions and preferences.