As the seasons become more fluid, with an earlier start to spring, cool-season vegetables like beetroot, carrots, radishes and parsnips can grow at cool soil temperatures of 10-21°C in the root zone, which is 10-15cm below the soil’s surface.
An easy way to check the soil temperature is to push your fingers into the soil. If the soil still feels cold the soil temperature is probably below 10°C but if it doesn’t feel cold it has probably reached 15°C which is the perfect soil temperature for planting cool-season vegetables.
This is quite achievable in a spot that receives full sun, which most veggies need to thrive.
Best companions for root veggies
Companion planting is a sustainable way to grow veggies. Quite simply, it is about planting flowers, herbs or other veggies that repel specific insects, improve the soil or attract beneficial pest predators for the benefit of a particular vegetable.
Beetroot and companions
Onions, chives and spring onions as well as catnip are particularly good companions for beetroot because they repel many common insects, including aphids.
if you have the space, sow a row of each, next to each other. Other good companions are dwarf beans, lettuce, and cabbage. However, beetroot grows poorly near mustard.
Catnip (Nepeta cataria) is a hardy perennial that likes full sun and rich, moist soil. It can grow about 50cm high. To keep it compact and bushy, pinch out the growing tips. It is a member of the mint family but is not invasive. The serrated dark green leaves have an antiseptic mint like smell and it has small white flowers. Your cats will love it.
Growing tips for beetroot
- Before sowing, loosen the soil, break down soil clumps, and remove, sticks and stones so that the roots can grow down easily.
- Sow seeds 3cm apart, in full sun, directly into the soil about 2cm deep in rows 30cm apart.
- Keep the soil moist during germination, which occurs within seven to 14 days.
- thin out the seedlings to about 5cm apart when they are about 5cm high.
- Carry out a second thinning when seedlings are 7cm high.. The remaining beetroot should be about 10-15cm apart.
- Water regularly throughout the growing season.
Good to know: harvest when the roots are 5-10cm in diameter. Cut off the tops leaving 2-3cm long stems. Store leaves and roots separately in the fridge. Use leaves within days. Roots will keep for 2-3 weeks.
Kirchhoffs heirloom beetroot varieties: ‘Bulls Blood,’ ‘Crimson Globe’ and’ Detroit Red
Carrots and companions
Onions, rosemary, wormwood or sage planted close to carrots will repel carrot flies. Carrots also enjoy the company of leeks, peas, lettuce, chives, parsley and tomatoes. If planted nearby, Bad companions are dill, potatoes, kohlrabi, fennel and cabbages.
Sage ( Salvia officinalis) thrives on neglect. Plant it in full sun, in soil that drains well and don’t over water.. Fertilise once a month in summer. Cut back after flowering to keep it bushy. It is also a good companion plant for strawberries and cabbage.
Growing tips for carrots
Grow carrots in well-prepared soil that is free from obstructions – clumps, sticks, stones and miscellaneous debris. If your soil tends towards sand or clay, work in compost to improve its quality.
Sow seeds fairly thinly directly into the soil about 1cm deep in rows 20-30cm apart. The bed should receive plenty of sun.
If you don’t have space you can sow “Little Fingers,” which is a baby carrot, in deep containers that contain a mix of potting soil and compost (to retain water).
Keep the area moist until the seeds germinate, which could take up to 10 days, so be patient.
As soon as the seedlings are about 5cm high start thinning out to 2cm apart. A week or so later, thin the rows a second time to about 5cm apart. Thinned out carrots are delightful additions to salads.
Water regularly and feed once a month with a liquid organic fertilizer. Feed those in containers, once a week.
Kirchhoffs heirloom carrot varieties: ‘Cape Market,’ ‘Chantenay Karoo,’ ‘Little Finger’ and ‘Nantes’
Radishes and companions
Radishes are a quick and easy crop that acts as a companion veggie to many other crops like lettuce, carrots, cucumber, spinach and bush beans.
For instance, radishes sown next to carrots, lettuce and spinach or Swiss chard break up the soil that improves the germination rate of the veggies. Radishes help to repel cucumber beetles and most insects prefer to chomp on radish leaves.
In turn, radishes benefit from being planted close to aromatic herbs like chervil, chives, and oregano that repel pests and improve the flavour of the radishes.
Chives (Allium schoenoprasum) or Garlic Chives (Allium tuberosum) are both perennials with deep green onion like leaves. Plant in full sun or partial shade. They grow easily in any soil and should be watered regularly. They grow in clumps to a height of 50cm.
Growing tips for radishes
- Sow a row of radish at a time for a consistent supply.
- and you won’t be overwhelmed by an oversupply.
- Sow in well tilled soil in rows in a sunny bed.
- Germination takes three to eight days and radishes are ready for picking from three weeks. The nicest radishes are pulled before they are fully grown.
- Water the soil the night before and pull out the largest to make room for the rest to grow. Regular watering will produce crisp, tasty radishes.
Kirchhoffs heirloom radish varieties: ‘Sparkler’ and ‘Cherry Belle.’
For more information, visit the Kirchhoffs website.
Article and images supplied by Alice Coetzee.
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