Swiss chard – more commonly grown than true spinach – is easy to grow and packed with nutrients.
Swiss chard looks a lot like the true spinach but has much broader leaves, thicker stems, more vitamin A, and greater yields. Vitamin A prevents night blindness, chronic fatigue, heart disease, stroke and cataracts. It is a valuable source of Magnesium which supports bones and teeth and boosts the immune system.
Swiss chard also has quantities of readily available minerals of which iron is the most important.
Swiss chard is grown for its nutritious, luscious leaves. Leaf and stem are both edible and can be cooked separately or as one.
Younger spinach leaves are more palatable and often have a higher concentration of vitamins.
This crop is relatively easy to cultivate and can be regularly harvested. Average yields range from eight to 10t/ha.
SOIL AND CLIMATE
Spinach does best in fertile, well-drained sandy loam soil. But it also does well in loamy to clay soil with a pH of between 6 and 6,8. It is a cool weather crop but will grow in hot months. If it’s too hot there may be bolting (seeding) in some cultivars.
Optimal temperatures range between 16°C and 24°C.
Choose a cultivar that suits the season and your yield requirements.
CROP ROTATION AND LAND PREP
Don’t plant the crop on the same land every year. It leads to pest and disease build up in the soil. Rotate with pumpkin, beans, peas, tomatoes, lettuce and cabbage.
Clear the planting area of weeds including grasses. Water the soil well before preparation to reduce compaction, enhance drainage, root penetration and soil aeration. Then loosen with a plough or fork.
Spinach needs a lot of compost (manure) as well as fertiliser.
The seed bed must be well prepared for direct sowing and have a fine structure. Big clods of earth will prevent germination.
PLANTING METHOD AND SPACING
Seedlings can be planted 10cm to 20cm apart, in rows 25cm to 35cm apart.
Seeds can also be planted directly in shallow rows or furrows. Use a spade or a rake to make the furrows 2cm to 3cm deep. Sow the seeds 2cm apart and cover with soil, smoothing it down with a rake. Water straight after sowing and cover with a thin layer of grass if it’s hot. Keep the soil damp as you wait for germination which takes between seven and eight days.
Take off the grass mulch after five days to give the seedlings room to germinate. If they have to struggle through the layer of mulch they will develop tall stems which makes them top heavy and more prone to sun damage.
Thin the seedlings out to the 10cm interplant spacing distance not later than three weeks after emergence.
Use 2:3:3 (22) Zn before planting. Apply 90g/m2 and work it into the top 10cm of soil.
Top dress three weeks after planting seedlings or emergence, at a rate of 16g LAN per 1m row. Apply 5cm to 15cm away from the plants on both sides. This is an 8g application per 1m row if you take it on one side of the plants.
Don’t apply the LAN directly onto the plants. It will burn them. Straight after application, mix the fertiliser into the top 2cm with a fork.
Be careful not to damage the shallow roots, especially in the early stages of growth. Water immediately after working in the fertiliser.
Top-dressing is very important. Spinach needs a lot of Nitrogen (N) to produce good quality, broad leaves and good yields.
Apply a second top-dressing eight weeks after transplanting or emergence, especially in lighter soils.
Trials have shown that good yields are possible in a low input system, using only compost as fertiliser. So even if farmers are resource- and cash-poor they can grow spinach. And if there are some chickens around, chicken manure will help especially with the N requirements. Nitrogen enhances the yield of leafy crops.
N deficiency affects the succulence and the nutritional value of spinach; too much N causes nitrate accumulation in the leaves and roots.
The soil must be moist throughout the growing season, because spinach has a shallow rooting system. The crop needs an irrigation cycle as frequent as once or twice a week.
Avoid over-watering and try to irrigate early in the day so that the leaves are dry by nightfall. Pests lurk in moist places.
HARVESTING AND STORAGE
Harvest regularly to stimulate regrowth and a higher yield that won’t bolt (go to seed) easily. Harvest by taking off the outer leaves with a sharp knife 30mm above the soil.
Under normal conditions the plant can be grown for five months before new plants are sown or transplanted.
If the leaves are not for immediate use, bunch them and place them in water to keep them fresh for longer.
Because of the high transpiration rate of the broad leaves, the keeping quality is poor. Stored in a fridge or cold store, spinach will keep for six to eight days.
PESTS AND DISEASE
Spinach may suffer from a number of diseases. The best way to avoid this is to keep the plants healthy by providing the right nutrition, enough water and a good start.
Monitor the crop and keep scouting for pests, removing them as you see them.
For aphids, and red spider mite, a weak solution of soapy water (you can use Sunlight liquid) will do the trick.
Cutworms hide under the soil and come out at night to feed. They cut the seedlings down at the soil/air interface. Use cutworm bait and keep checking.
To keep diseases and pests at bay, rotate and intercrop with marigold, mustard and rapeseed and leave the land fallow.
Klein Karoo Seed
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Klein Karoo Seed
Phone: +263 4 746179
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Sakata Agent- Paxton
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Sakata Agent -Bulawayo Seed Co
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Phone: +260 21 124 3441