Did you know the Brassica genus consists of many commonly eaten vegetables?

In Singapore, Brassica edibles are highly popular and widely cultivated in our allotment/community gardens. They are often cooked in our local cuisine via stir fry or boiled as well as eaten raw in salads.

These vegetables come from the wild cabbage family and can be grown from seeds. They are generally termed herbaceous annual which means they die completely at the end of its growing cycle. Some of its common growth requirements/characteristics include:

• Grows best in fertile and well-draining soil
• Requires four to six hours of sunlight with moderate watering daily
• Takes around minimally one week for seeds germination and about one and a half month to harvest after seeding transplanting

Beside growing the seeds on ground plots, these plants can also be grown in pots and via a hydroponic system as they have shallow roots of about 10 cm deep.

Common Brassicas
Here are some examples of the common Brassicas grown in Singapore, along with their germination and harvest cycle:

Kow Peck Chye (Brassica rapa)

Photo credit: Justin Chua Qi Zhang

Belonging to the Pak Choi group, this is a larger form of Bok Choy. A distinctive feature is that it has dark green leaves with very white petiole. ‘Peck’ refers to white in Hokkien, which shows that there are some parts of the vegetable that are white (that is, the petiole). 
Germination time: About seven days
Harvest time: 30 to 45 days

Huang Jing Bai Cai (Brassica rapa)

Photo credit: Vicky Lim Yen Ngoh

Also from the Pak Choi group, its leaves have a lighter green colour and appear to look a little crumpled. It is also commonly known as Chinese Cabbage as its native distribution is from China.
Germination time: About seven days
Harvest time: 30 to 45 days

Nai Bai (Brassica rapa)

Photo credit: Jennie Tang

Growing up to about 14 cm in height, this is a tiny-sized Bok Choy with a milky white petiole. ‘Nai Bai’ refers to milky-white colour in Chinese. It is from the Pak Choi group.
Germination time: About seven days
Harvest time: 30 to 45 days

Cai Xin (Brassica rapa)

Photo credit: Jane Li

From the Parachinensis group, it is distinguishable by its yellow flower with a slender and smooth stem. The common name of Cai Xin is the Chinese Flowering Cabbage as both its leaves and flowers can be eaten.
Germination time: Three to five days
Harvest time: 30 to 40 days

Kailan (Brassica oleracea)

Photo credit: Jennie Tang

It has bluish green to dark green coloured leaves with thick stems that are smooth and pale green in colour. ‘Lan’ refers to blue in Chinese, which accurately describes its bluish coloured leaves. It is from the Alboglabra group.
Germination time: Three to five days
Harvest time: 21 to 55 days

Once these plants reach around 20 cm tall (10 cm for Nai Bai) or the desired size, you may harvest the edibles by uprooting the whole plant. Alternatively, you may use the cut-and-come again method to harvest for endless supply of vegetables (e.g. Kow Peck Chye, Huang Jin Bai Cai and Nai Bai etc).

Another indication to harvest your plant is when you spot flowering. Once the flower blooms, the vegetable might be over matured and a little too old for consumption. However, you may still eat the flower from the Nai Bai and Huang Jin Bai Cai.

Tips on Growing your Brassicas

1. Prepare your plot by ensuring the soil is well-prepared with nitrogen-rich organic fertilisers.
2. Raise seedling using the seed tray method to prevent overplanting, overcrowding, and damaging of root during transplanting.
3. Space the seedling at 10 to 15 cm apart to ensure good air circulation with sufficient space for the plant to grow.
4. Ensure that the plants received four to six hours of direct sunlight daily to grow well.
5. To promote the growth of leaves, add fertiliser to your soil regularly to supply sufficient nitrogen (N).
   1. Leafy vegetables need fertiliser high in nitrogen to grow more leaves.
   2. Usually fertilise once every two weeks or follow the manufacturer’s instructions.
   3. Use processed animal manure with high N content (e.g. chicken or goat pellets).
6. Consider installing netting as a form of pest control to avoid insects like snails, grasshoppers and leaf miners.
   1. Mechanical or physical control is one of the approaches for Integrated Pest Management. This involves the use of traps, screens or nets to prevent pest activity or to remove pests from an area.
7. Harvest the plant roughly a month after germination or before it flowers. Otherwise, the leaves might be very tough to chew when the plant gets old.

 

Gardeners’ Day Out Is Back!
Participate from the comfort of your home with online activities such as talks and demonstrations, video tutorials of activities and promotions offered. Free guided tours will also be offered on site (with safe management measures). Enjoy Gardeners’ Day Out online at www.nparks.gov.sg/GDO.

You can also enjoy our Gardening With Edibles Masterclass Series from your home. They are conducted by NParks horticulturists, focusing on unique and challenging edibles across different plant families.

Gardening with Edibles
The City in Nature vision seeks to bring greenery closer to all residents. The community plays a key role in the ownership and stewardship for nature which will benefit our health and well-being.

NParks is partnering residents to make Singapore our City in Nature and spark a love for community gardening through the Gardening with Edibles initiative under the Edibles Horticulture Masterplan. Under the Gardening with Edibles programme, some 860,000 free seed packets have been distributed to interested members of the public since its launch in June 2020. The programme was established by founding partners DBS Bank and Tote Board through the Garden City Fund, a registered charity established by NParks. The most recent round of seed distribution, which took place in December 2021, was made possible by the programme’s partner Singapore Post Limited, also through the Garden City Fund. Relevant resources are available online, to guide gardeners along the way.

The Gardening with Edibles initiative is aligned with Singapore’s national strategy to strengthen our food resilience. The “30 by 30” goal, led by the Singapore Food Agency, aims to produce 30% of Singapore’s nutritional needs locally by the year 2030.

Also, NParks is expanding the allotment gardening scheme and the Community in Bloom programme, to welcome even more residents into the gardening family.

If you are a gardening newbie, visit NParksSG, our refreshed YouTube Channel that serves as a one-stop repository for close to 300 video resources. It covers topics ranging from types of soil needed for your garden and how to plant, harvest and even cook your edibles.

For more information about the flora and fauna found in Singapore, please visit Flora and Fauna Web.

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Text by Teo Xin Ni

About the writer

Teo Xin Ni is a Community In Bloom manager under the Horticulture and Community Gardening Division. Her primary work includes community engagement of community gardening groups and creating educational materials for outreach. She enjoys taking photos of edibles in our local garden and is always excited to learn from our friendly community gardeners.