Ask the Plant Doctor! How to start a herb garden

Shazli’s balcony garden on the 8th floor. Photo: Shazli Taib

Do you have a question about plants or how to maintain your garden? Send your questions to the Plant Doctor! Email your questions to [e-mail] with "Plant Doctor" in the subject field. Questions may be edited for brevity and clarity.

Q I would like to reorganise and start a herb garden with perhaps one medium-sized tree in the middle. The right side will be a small pond with small koi.

There should also be a bird bath, but I have not decided the location and size of it yet. Would love to hear your thoughts and ideas on the kind of herb plants and tree for me to start with. I am on the 8th floor. Thank you. – Shazli Taib

You have a variety of options from which to choose for your herb and tree garden. Basil (Ocimum basilicum) and Thai basil (Ocimum basilicum var. thyrsiflora) are two closely related herbs with distinct flavours, and both require pots approximately 20-30cm in diameter.

Mint (Mentha spp.) and Daun kesum (Persicaria odorata) are also good options for container gardening. They thrive in slightly larger pots around 20-30cm in diameter. Pandan (Pandanus amaryllifolius) and lemongrass (Cymbopogon citratus) also make excellent choices, but because of their larger roots, they require pots with a diameter of 30-40cm.

For small trees in your garden, try calamansi (Citrofortunella microcarpa) and Thai lime (Citrus aurantifolia), which are well-suited for balconies and can be grown in large containers measuring 45-60cm in diameter.

Additionally, curry leaf (Murraya koenigii) and kaffir lime (Citrus hystrix) trees are also good choices, requiring full sun exposure and pots with a diameter of 30-40cm.

To maximise space, vertical gardening techniques can be considered, such as hanging baskets, wall-mounted planters and trellises. This approach allows the growth of more plants without overcrowding the balcony floor.

To ensure the health of herbs and trees, ensure that all pots have proper drainage holes to prevent waterlogging.

Additionally, ensure that all plants receive adequate sunlight, as most herbs and citrus trees require several hours of direct sunlight.

Opt for a small bird bath (30-45cm in diameter) and a small fish pond of approximately 90cm x 60cm can support a few small koi. It is essential to consider the combined weights of all the elements included.

The cumulative weight of plants, trees, bird bath and koi pond, along with the weight of their respective pots, soil and water, can be substantial.

Verify that your balcony has the capacity to support it without any risk of damage or instability.

Assoc Prof Dr Christopher Teh heads the Department of Land Management, Faculty of Agriculture, Universiti Putra Malaysia. His field of specialty is in soil and water conservation. The views expressed are entirely his own.