As the name suggests, lime basil has a tangy, citrusy aroma, making it ideal for preparing many delicious dishes and refreshing drinks.
Lime basil (Ocimum americanum) is easy for everyone to grow, whether in a bed, on the balcony, or on the windowsill. What is more, lime basil is not only tasty but also super nutritious – a real wonder in the kitchen. Read on to find out how to sow and care for this aromatic culinary herb as well as how to use it.
Lime basil: origin and properties
Lime basil, also known as American basil, belongs to the mint family (Lamiaceae). It originated in India and other tropical regions, including certain countries in Asia, Africa and South America. Due to its native habitat, it requires high temperatures to thrive.
This annual herb has a compact, bushy growth habit. It has upright shoots that reach up to 40 cm tall. The flower buds as well as the leaf stalks and undersides are slightly fuzzy.
Lime basil leaves are somewhat smaller than those of the well-known Genovese basil (Ocimum basilicum ˈSweet Genoveseˈ). They are also narrower, taper to a point and have slightly toothed edges. Unlike the classic basil types and varieties, lime basil leaves do not cup upwards but are flat.
Lime basil blooms from June to September. It is a monoecious plant, meaning it produces both male and female flowers. Lime basil flowers are symmetrical, pale purple to white and sit atop a single inflorescence. However, as they are not rich in pollen or nectar, they are not particularly beneficial to bees and other pollinators. The flowers later produce black seeds, which have a smooth surface and are about 1.5 to 2 mm in size.
Is lime basil a perennial? No, lime basil is not a perennial. It is an annual that goes through the generative growth phase during its first (and only) year. During this phase it produces flowers and later seeds. The plant then dies towards the end of the year.
Other basil varieties
Here are some of the many basil varieties.
- Ocimum x africanum (syn. Ocimum americanum var. pilosum): This variety is known as lemon basil, hoary basil, Thai lemon basil or Lao basil. It is a hybrid between Ocimum americanum and Ocimum basilicum and grows about 30 cm tall. It has an intense lemony aroma.
- Ocimum basilicum ‘Mrs Burns’ Lemon’: This variety has mid-green leaves and again has a lemony aroma. It reaches anywhere from 10 cm to 50 cm high.
- Ocimum tenuiflorum (syn. Ocimum basilicum ‘Holy basil’): Holy basil, sometimes known as monk’s basil or purple-stalked basil, reaches up to 50 cm tall. This bushy variety has purple-green leaves and pink flowers. In terms of flavour, it is very aromatic.
Growing and sowing lime basil: where and how
Lime basil prefers a warm, sunny and wind-protected spot. Only plant the basil outdoors when temperatures are expected to stay above 10 °C. A well-draining, humus-rich soil with sufficient nutrients and moisture is ideal for this heat-loving herb.
Lime basil also grows well in pots, ideally with a capacity of about 8 – 10 litres. Make sure the pot has drainage holes to allow excess water to run off. Put some expanded clay or gravel in the bottom of the pot to create a drainage layer. Fill the pot with a high-quality potting soil. Lime basil requires more nutrients than most other herbs. So, our Plantura Organic All Purpose Compost is ideal as it contains enough nutrients and fertiliser to meet all the herb’s nutrient needs.
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You can also sow lime basil seeds directly outdoors or in a greenhouse from around mid-May. However, if the temperature is not optimal, the seeds may take longer to germinate. This also delays the start of harvesting. Starting the seeds indoors brings the harvest forward and allows you to make the most of the growing season. Here are some step-by-step instructions on how to grow your own lime basil from seed:
- Start sowing seeds indoors from mid-March
- Fill the pots with seedling soil
- Press the seeds down lightly (lime basil seeds need light to germinate, so do not cover with soil)
- Sow several seeds per pot to produce bushier plants
- Keep the soil moist
- Place the pots in a warm, bright spot
- Germination temperature: 18 – 25 °C
- Germination time: 10 – 15 days
- Once the plants reach 5 – 10 cm tall, transfer them to a larger pot with a more nutrient-rich soil
- Wait until temperatures stay above 10 °C to put your lime basil outdoors
Lime basil is not particularly demanding. Nevertheless, there are a few things you will need to check on a regular basis.
When it comes to watering lime basil, make sure the pot’s soil is always slightly moist. Avoid dryness and waterlogging. Once the top layer of soil is dry, water again a little.
During the growth phase, fertilise your lime basil every one to two weeks with a liquid fertiliser, such as our Plantura Liquid Tomato Food. The nutrient composition of our fertiliser is optimally adapted to the high requirements of this herb. It is also ideal for feeding potted plants as it is easy to apply – simply dilute it into the water you use when watering. It is especially important to fertilise if you are harvesting the leaves regularly.
As it happens, regular harvesting is actually an important maintenance measure as it stimulates growth, encourages branching, and prevents premature flowering.
Is lime basil winter hardy?
No, lime basil is not winter hardy. It will all but stop growing at temperatures around 12 °C and lower. However, as it is an annual herb, winter hardiness is not all that important. To extend the harvest period or to allow the lime basil seeds the time they need to mature, bring the plant indoors in a pot from autumn onwards. Place it somewhere with enough light and warmth.
Harvesting and uses
When harvesting lime basil, always cut off whole shoot tips rather than individual leaves. This encourages the plant to branch out and delays the formation of flowers. As long as you do not plan on harvesting the seeds, it is best to remove the flowers as they can affect the growth and flavour of the plant. In fact, along with the leaves, the flowers are edible as well. However, as these are quite bitter, they are usually used as a garnish. As far as flavour is concerned, lime basil leaves have a typical basil aroma mixed with an intense, fruity lemon taste.
Lime basil leaves are excellent for using in fish dishes, exotic rice dishes, and also in desserts and sweet dishes. To retain as much of the refreshing aroma as possible, use the leaves directly after harvesting. When using in warm dishes, only add them towards the end to avoid heating them up.
On top of adding a herby tang to dishes, you can also use lime basil to elevate drinks. Why not try using it to make refreshing cocktails, sparkling lemonade, or even a soothing lime basil tea? You could even make lime basil syrup.
Unfortunately, drying lime basil is not a good way to preserve it because a large part of the aroma is lost during the drying process. We instead suggest you freeze the leaves or use them to make a lime basil infused oil or pesto.