The A to Z of farming courgettes

Zucchini (Cucurbita pepo var. cylandrica) or courgette is slowly becoming a favourite crop among Kenyans if its growing presence in the market is anything to go by.

As demand increases, it is important farmers get it right when growing the crop.

Zucchini need soils with high organic matter and good moisture-retaining capacity.

It is recommended you add one wheelbarrow of compost and or manure to each metre square of soil and prepare a raised bed, about 25cm high to keep zucchini leaves off the ground.

The crops need a pH of 6 to 7.5. So liming is a must if your soil test shows that your pH is below that.

The recommendation that accompanies the soil test will give you the exact amount of lime that is needed to raise your pH to an adequate level.

Remember, lime has to be applied and then thoroughly incorporated into the soil during land preparation or weeding.

It is good to apply lime just before the rains start, and better a few months before you plant as the mineral slowly reacts in the soil, thus, its positive effects will be seen a few months later.

PLANT IN FULL SUN

Zucchini is a warm weather crop but it can withstand cooler conditions better than other cucurbits like cucumber or melon.

It is important to mention that zucchinis are not tolerant to humidity, which causes mildew. Therefore, plant them in full sun.

To improve the germination rate, soak the seeds for three days between two wet kitchen towels. Use only seeds that have partly germinated.

Sow three seeds at 1.5cm deep per planting hole. Then thin out to the most vigorous plant after two to three weeks.

Alternatively, you can grow two plants at opposite edges of the seedbed. Some varieties might need a climbing support to improve air circulation around the plant.

The growing vines need to be supported regularly to avoid breakage or touching the ground, but most varieties will form big, sturdy non-climbing plants.

Top-dress with compost after four weeks or use liquid fertiliser. You can make your own liquid fertiliser at home by soaking chopped leaves of tithonia, stinging nettle or comfrey (or a mixture of all of them) in a bucket of water.

Cover the bucket loosely and stir the mixture with a stick daily to incorporate some oxygen into the brew. It will start to bubble and “smell” after a few days. That is a good sign, it means your liquid fertiliser is about to be ready.

After two weeks, the bubbling stops meaning your fertiliser is ready for use. You will find that the water has become a green liquid and that all the leaves have turned into a kind of slush. Strain the liquid through a sieve and store it in a canister.

For application in the root zone of your plants, dilute it 1:10 (put a litre of the fertiliser into a 10 litre watering can and fill it with water). Pour a bit of it onto the soil next to each plant. Weekly applications are recommended.

If you want to use it as a foliar spray, simply strain it in a cloth to avoid clogging of the sprayer and dilute it 1:20 (put half a litre of fertiliser into your 20 litres watering can and fill it up with water).

CUT FRUITS OFF

To grow your zucchinis successfully, keep the soil moderately moist throughout. Always make sure you don’t wet the leaves. So never water overhead. Mulching with straw is recommended.

Harvest is done by cutting the fruits off rather than pulling fruits off to avoid damaging the plant.

Zucchinis can be grown all-year round except during periods of heavy rains as they destroy the flowers and promote mildew.

It can be grown in a seedbed and transplanted at three-leaf stage, but sowing directly in situ works just as well. Recommended spacing is 120 by 60cm since the plants grow quite big.

Harvest starts after eight weeks and usually continues for another month. Pick regularly to encourage production of new fruits.

The zucchini fruits look similar to cucumbers but have a firmer flesh. They are eaten raw or cooked and are popular in hotels and restaurants. Young shoots, leaves and flowers are a delicacy, and can be eaten raw in salads or fried.

The crops are attacked by pests and diseases similar to those that affect cucurbits (cucumber, melon and pumpkin) although zucchini is the toughest of them all.

They include fruit flies, epilachna beetle, spider mite, white fly, powdery and downy mildew and wet rot (if vines are grown on the ground), mosaic virus and wilt.

Ms Weber is the country manager of SoilCares Limited