Root vegetables enjoy a moist, well-cultivated soil, packed with plenty of rich organic matter, such as homemade compost or well-rotted manure. The exception to this rule is carrots and parsnips. Carrots and parsnips prefer a light, sandy soil. If grown in a soil that is rich with manure or compost, they can fork and grow into strange shapes.
Beetroot is a very easy crop to grow, and is ideal for beginners. For best results you should sow the seeds regularly, a few at a time, and harvest the roots when they are young.
Each beetroot seed is actually a small fruit, which will yield up to three seedlings. Prepare the soil well, removing stones and weeds and raking it level. Sow one seed per station, at 10cm intervals, and roughly 2.5cm deep in rows 30cm apart.
When the seedlings are about 2.5cm high thin them out to leave one seedling per station. Keep the seedlings moist, watering regularly is necessary and pull out any weed seedlings that emerge. When the roots have grown into the size and shape of a golf ball, they are ready to harvest as ‘baby vegetables’. Pull up alternative plants to leave the remaining roots room to keep growing to maturity.
If you make regular sowings, you can enjoy fresh carrots nearly all year round. Prepare the soil to a fine tilth and sow the seeds 13mm deep in rows 15cm apart. Try to sow the seeds as thinly as possible to avoid having to thin them out later on. Thinning then out involves removing seedlings to make space for them to grow properly. However the process generates a rich, carroty smell, which alerts the carrot root fly to your crop. To extend the growing season, sow seeds under a cloche in early spring.
Keep the soil moist to avoid splitting the roots. Cover the tops of the roots with soil or straw to prevent them from getting ‘green shoulder’. Harvest them as soon as they are large enough to use – dust off the top layer of soil to reveal the top of the carrot. If it is more than the diameter of a five pence piece it is ready to harvest.
Parsnips are easy to grow and can be left in the soil until ready to use. In March, sow three seeds per station, 13mm deep in rows 30cm apart. Parsnip roots take a long time to germinate so consider growing radish in the same planting hole to mark the spot (the radish will have been ready and eaten long before the parsnip needs the space).
When the seedlings are about 2.5cm high thin them to one seedling per 15cm station. Keep the soil moist to avoid splitting the roots. The roots will be ready to lift when the foliage starts to die down; use a fork to carefully lift them out of the ground, and place straw over the tops to prevent soil freezing around the roots if you are saving them for a later harvest.
There are three main types of potato – first earlies, second earlies and maincrops, depending on when they are planted and harvested. If you have the space, grow all three types to ensure a long cropping period, and store maincrops over winter. You can extend the season further by planting first earlies from late February under fleece or cloches.
Chitted seed potatoes tend to produce a heavier crop. To chit your seed potatoes, stand them rose end up (the rose end has the most eyes, or shoots) in egg boxes in a light, frost-free place. The tubers will be ready to plant when the shoots are about 2.5cm long.
Plant first earlies in March, second earlies in mid April and maincrops in late April. Dig a narrow trench 12.5cm deep and line it with grass clippings (this prevents scab). Space early tubers 30cm apart and maincrop varieties 37.5cm apart in rows 60-75cm apart.
When the stems are about 23cm high earth them up by drawing soil up to the stems and covering them to produce a flat-topped ridge about 15cm high. This protects the stems from any late frosts and encourages the growth of more tubers.
You can also grow potatoes in large containers. Plant the seed tubers just below 15cm of potting compost. As the new stems grow, keep adding compost until the container is full. Water crops in dry weather and again when they are in flower (this is when the plants are forming the tubers).
First earliest should be ready to harvest in June and July, second earliest in July and August, and main crops from late August through to October.