Basil is susceptible to cold weather and frost. Planting this herb in warmer areas will ensure that young plants don’t die off.
Grown commercially, basil is often cultivated under cover, in tunnels. Herb farmer, Jimmy Kabotha, says that good tunnel infrastructure is essential for herb farming and makes it possible to produce herbs in winter.
Remember, though, that tunnel heating is crucial for crops such as basil in winter and this might make production too expensive. Basil can also be cultivated outside.
The South African Department of Agriculture, Forestry and Fisheries (DAFF) guidelines for basil production indicate that the period from the end of August to October is the best time to plant seeds directly or to transplant seedlings. Basil is mainly propagated from seed, because they germinate easily and seedlings develop quickly.
For direct seeding, plant seeds 3 mm to 6 mm deep and space them 5 cm apart. The optimum temperature for germination is 20°C; growing temperatures are 7°C to 27°C. The minimum annual rainfall for dryland cultivation is 700 mm and a soil pH of 6.4 is best.
- Basil grows best in full sun and well-drained soil, but the plants should be sheltered from direct wind.
- According to the blog, The Herb Gardener, a layer of mulch around the seedlings will reduce moisture loss.
- Moisture is also retained more easily if the herb is planted in an area that receives afternoon shade.
- Basil requires regular irrigation throughout the growing season to maintain constant growth. If rainfall is not sufficient, water using sprinklers or drip irrigation.
- Herbs perform best if they receive water at root level; otherwise they tend to discolour. Moisture on the leaves can cause fungal diseases, such as mildew, so consider drip irrigation.
- Basil responds well to soils of moderate fertility, but before applying fertiliser, find out what the soil type is and whether there have been previous crop and fertiliser applications.
- Any fertiliser recommendations should be in keeping with the results of a soil analysis.
- In most cases, good-quality compost and a little processed manure is adequate as fertiliser.
- If you need to apply fertiliser on a large scale, you can mix it with water and apply the dilution via irrigation or by using a siphon attachment on your hose.
- Cultivation practices such as high plant densities, shallow cultivation, decreased row spacing and mulching are some ways to control weeds.
- The DAFF guidelines advise farmers to only use certified weed-free seed and to choose a cultivar that offers rapid seed germination and plant growth.
- If you mulch the crop, make sure it, too, is weed free.
- Herbs such as basil are notorious for attracting white fly, a perennial greenhouse pest.
- Scout regularly for pests such as beetles, slugs, leaf miners, caterpillars, grasshoppers, leafhoppers and thrips.
- Fungal, bacterial and nematode diseases occur more frequently in basil than in most other herbs.
- Try companion planting to combat pests.
- Basil does well with tomatoes, green peppers, marigolds, fennel, cucumbers, courgettes, oregano, asparagus and squash.
- Basil should not, however, be planted with rue.
- You could also use natural herbal pest control sprays rather than chemical applications.
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- This article was written by Wilma den Hartigh and first appeared in Farming SA.