Lemon basil, popularly called “curry plant” is a herb with a sweet citrus fragrance. In Nigeria, it is popularly used in cooking stew. It has a lot of health benefits because of the minerals (magnesium, iron, manganese, copper, calcium,) and vitamins (rich in vit A and K) it contains. It also contains the compounds limonene and citral, which have  some anti-inflammatory properties (i.e. ability to reduce redness, swelling, and pain in the body). Below is a guide, based on my experience, on how you can grow and make money with lemon basil. You can make lots of money from this during the dry season when tomatoes are cheap. But once tomatoes get scarce, demand falls because it is mainly used in stew. Because of this, it is not good to grow one type of vegetable. I grow green amaranth, scent leaf, fluted pumpkin (ugu) leaves in addition to curry.

Lemon basil can be planted from seeds or cuttings. Seeds can be gotten from mature plants that have flowered and the seeds allowed to dry (more on this later). 

Planting from Cuttings

This is the quickest way of planting lemon basil. Just cut the branches of mature plants, remove any flower or bud and plant directly in the field. Water immediately and repeat whenever the top soil start drying. Spacing can vary. For me, I use about 10-15cm between plants and rows.

To plant cuttings in the field, I make beds measuring about 60cm wide with any length of my choice. I have seen farmers using large beds of about 1m wide. I don’t like that because harvesting and weeding such farm is stressful. With shorter beds, your hand can easily reach the other side without stepping on the bed. 

So make your beds, mix in lots of manure in them and plant. During the dry season, plant on flat beds to save irrigation cost.

Planting from Seeds

I don’t normally plant from seeds because of is more time-consuming. Anyway, seeds should be planted in a nursery and later transplanted to the field. Prepare the nursery bed and sterilize it by burning a pile of dry grass on it. This will get rid of soil-borne diseases, soil pests and nematodes. An alternative is to drench the bed with hot water. Allow the bed to cool down before sowing the seeds.  Mix in lots of aged manure (about 25 liter of manure per square meter) into the top 15-20cm of the soil and level the bed with a rake. 

Before sowing, level the bed and pat it down lightly with your palm. Water deeply, sprinkle the seeds evenly on the bed and cover with a small layer of soil. Bury seeds no more than 0.5cm deep. Don’t place anything on top of the nursery bed to maintain good ventilation, as lemon basil seedlings are very sensitive to damping off. 

Lemon basil seeds need warm air and soil temperatures to germinate. Wet and damp conditions might cause seeds to rot in the soil, or they may take twice as long to germinate. In that case, growing indoors might be the best option for you. If you’re growing indoors, grow them in containers or nylon bags with drain holes at the bottom. This will enable you to bring them out whenever the sun shines and take them back in when it rains. Minimum temperature req. for germination is 18.4°C for daytime and 10°C for night. Nigeria and most tropical country surpass this requirement through out the year.

Germination will start in 8-14 days. Be careful not to over water. Water only when the top soil begins to dry. To boost growth, water seedlings with a solution of liquid fertilizer every week. Seedlings are very sensitive to damping off, so maintain good ventilation. Neem oil and fungicides sprays can be used to control damping off.

Indoors, you can plant them in flat trays filled with hot-water sterilized soil. Press down the soil to form a level surface and wet it. Lightly sprinkle the seeds on the wetted soil and they will stick in place. That is why you should wet before sowing, otherwise the small seeds will move with the water and pile up in different places. After sprinkling the seeds, press them down gently and cover the tray with a clear plastic bag. No need to cover the seeds with soil. Place the tray near a window where it will receive enough light. Avoid direct sunlight. Once they germinate, remove the plastic covering. Keep the soil moist but not soaking wet to avoid root rot.

Transplanting: 

They will be ready for transplanting when they develop at least 2 sets of true leaves, 4-6 weeks after germination. Before you transplant, harden the seedlings by exposing them to direct sunlight. Do so for a week and do it gradually. On day 1, they may get 1h of full sun. On day 2, 2 hours. On day 3, 4 hours and so on. However, hardening isn’t necessary if you grew the seedlings outside. So far as the weather isn’t wet and damp, seedlings can survive outside. Transplant in the evening to minimize shock.

It is best to transplant lemon basil plants to beds rather than ridges to accommodate more plants. Prepare the bed 1 or 2 weeks before transplanting and mix in manure, using about 15L manure per square meter – the more the better. Rich soil and full sun will give good quality and yield. Beds may be 50cm – 1m wide.

Increasing Yield and Flavour: 

The secret for this is good fertilization. You can fertilize with manure every month and with NPK every 2 weeks. Applying foliar fertilizers like Haifa Bonus NPK ( @ 2-4 tablespoon per 16L water) every 4-7 days will give a very good result. The foliar fertilizer contains NPK, micro and macro nutrients like copper, zinc, manganese, iron, boron etc.

Irrigation: 

In this curry-growing business, the time to make lots of cash is during the dry season when tomato is available for stew. So you’ll need to irrigate. You can use handheld sprinklers, rain guns or spray tube. Among these, I choose spray tube as the best because it saves time, energy and fuel.

…..Pic of handheld sprinklers, rain guns or spray tube

Harvesting

Harvest can start when they are about 15cm tall. They can be harvested weekly to encourage growth and prevent flowering.  Don’t allow them to flower. If they do, pinch out all the flowers. Flowering reduce the leaf size and aroma. The plants will likely die if you allow them to flower and set seeds. And note: It can be quite time-consuming to pinch out flowers from many curry plants! So prepare for it.

As you harvest leaves, place them under shade immediately if the weather is hot. Else they will spoil before the day runs out. I once lost lots of harvest because of this. It is best to harvest early in the morning or in the evening.  Sell them as soon as possible. If you can’t, spread them out on the floor. They will heat up and rot if you leave them in a pile.

Pests and Diseases:

Some pests of lemon basil include slugs, snails, caterpillars, whiteflies etc. But a weekly spray of insecticides will keep them off. A good organic insecticide is neem oil.

I’ve not had any problem with diseases. Diseases will likely occur during wet season. So ensure that the plants are properly spaced (10-20cm apart) and that they are planted on raised beds for proper drainage.

Market

In some areas, lemon basil leaves are sold mainly on Saturdays and Sundays because most people use it in cooking Sunday rice and stew. There may be no or little demand other days. So, make sure you do market research before planting.

Saving Seeds

To save seeds, allow the plant to flower and develop seed heads. When the seed head turns from green to brown, harvest them. Don’t allow them to pass this stage or else the seeds will start dropping to the ground. Spread them on a tray in a place with good air circulation and out of direct sun.

Drying Leaves

I don’t know if their is market for dry curry leaves in my area. But you can still create the market. Dry them under shade because the sun will bleach the leaves and destroy many nutrients. When it is dry, put it into a nylon and seal tight. Store in a cool, dry place. Do not crush or grind the dried leaves. Rather, leave it whole and it will retain essential oils and fragrance longer.

Conclusion

Lemon basil plant is quite easy to grow and it can fetch you good sum of money; especially during the dry season when tomato is available for cooking stew. It is a very good plant to start with along with other vegetables.