Basil plant care: pruning, watering & fertilising basil
Basil is an essential part of any herb garden. Here is our guide to looking after basil at home!
Warmth-loving basil (Ocimum basilicum) is a kitchen staple. Its sweet, refreshing flavour makes for a delicious pesto, and enriches soups, sauces and vegetable dishes. For lush growth and an abundant harvest, however, your basil will need the right care. Unlike many other herbs, this Mediterranean plant needs plenty water and nutrients. What is more, as it is sensitive to the cold, basil needs potting during the cold months or – depending on the variety – overwintered.
Below are our top tips on basil care, watering and fertilising as well as a guide on how to properly prune basil.
How to water a basil plant?
Basil needs a lot of water to thrive, but it is important to avoid waterlogging. As is the case with almost any herb, waterlogging increases the risk that your plant will die from root fungus.
Similarly, unnecessary drought increases basil’s susceptibility to disease. As such, make sure your herb does not wilt from dehydration, which may mean you need to water it daily, especially if it is in a pot. But do remember: basil prefers dry foliage, as moisture on the leaves can lead to leaf spot disease, caused by a fungus of the genus Septoria. For potted basil, it is best to add water to the tray or saucer under the plant pot, so that the plant can absorb the water through its roots. This ensures a good, gentle supply of water for your basil.
Tips for watering basil:
- In summer, water daily if necessary to avoid drought stress
- Avoid waterlogging
- To prevent disease, do not moisten the leaves
- For outdoor basil, water around base of plant
- For potted basil, water via a tray or saucer underneath the pot
- Reduce watering during the dormant period in winter
Fertilising basil: What kind of fertiliser for basil plants?
Basil needs a sufficient supply of nutrients to produce abundant, aromatic leaves. This can be achieved through proper fertilisation. Apply an all-purpose plant food in spring – such as our Plantura All Purpose Plant Food – and work it into the top layers of soil or substrate. With the help of microorganisms, the fertiliser granules will break down gradually in the soil and release their nutrients slowly.
Apply some more fertiliser again in early summer, and, over winter, you can add a little less, as the basil does not grow quite as much.
- Perfect for a variety of plants in the garden & on the balcony
- Promotes healthy plant growth & an active soil life
- Long-lasting fertiliser that is free from animal products - child & pet friendly
For more, read our article on fertilising basil.
Generally, basil is very tolerant to pruning, so don’t hold back! Do, however, avoid picking off individual leaves, as this will stunt the shoots. Instead, harvest complete shoots. This will promote branching and suppress flower formation, which is important, because basil stores bitter substances in its leaves during flowering and dies afterwards. As such, be sure to cut off shoots that are about to flower. Always cut back basil shoots just above a pair of leaves, at no more than 5cm in height.
As with other plants, use clean and sharp tools when harvesting to reduce the risk of invading pathogens.
Only cut back perennial basil varieties in winter for harvesting purposes, as they won’t grow much in winter.
- Use clean and sharp tools
- Do not pick individual leaves, but cut off the entire shoot tip
- Shorten shoots to no more than 5cm
- Always cut above a pair of leaves
- Do not over-prune perennial varieties in winter
How to care for potted basil
You can care for potted basil in much the same way as you would bedded basil. However, do bear in mind that the root system of potted basil is restricted, so the plant has less access to nutrients and water than bedded basil. Water and fertilise your potted basil regularly.
Potted basil will need a little more attention than bedded basil, because basil sold in pots is usually sown far too densely. This means that the individual plants do not have enough space, and their leaves lack sufficient light. For this reason, it helps to take the plants out of their pots and thin them. To do this, carefully loosen the root system with your fingers and divide the clump in two. Then pot each basil clump in a separate pot with fresh compost.
It is better to pot perennial basil varieties, as this is the only way they can be overwintered. Perennial basil does not feel comfortable at temperatures below 10°C, so keep it in a bright, sunny location, and find a bright and warm spot when you bring it indoors in winter. Read our article on overwintering basil for more tips.