Asparagus is a delicious and healthy vegetable that is relatively easy to grow in Singapore. If you live in a tropical climate, these tips are relevant too. If you are interested in growing asparagus in your garden, read on, I will teach you everything you need to know about growing asparagus.
Asparagus is a member of the Asparagaceae family and is a perennial plant, meaning it will come back year after year. In the tropics, asparagus can take about 7-18 months to mature, depending on which variety you grow, and once mature it can produce for up to 20 years!
You can grow asparagus from seed or from crowns (roots). Overseas, it is common for people to procure crowns that are as old as 3 years old because it cuts the waiting time for asparagus plants to mature. In climates that experience winter, it takes around 3 years for asparagus plants to become productive. In Singapore, however, plants mature in half the time or less so people are more likely to grow it from seed instead.
Asparagus plants are either male or female. Male plants are sometimes preferred over females and more prolific at producing asparagus spears because female plants expend more energy producing berries. These are poisonous and should not be consumed. Female plants also do not live as long as male plants. This is why some people prefer to grow F1 male dominant hybrid cultivars.
How long does it take to harvest asparagus?
I used to think that it takes around 2-3 years to grow asparagus (Asparagus officinalis) to maturity in Singapore, but realised that because of our tropical climate it can take as little as 7 months for edible asparagus spears to begin forming. This depends on the variety you are growing.
Horti retails Mary Washington asparagus seeds which takes approximately 18 months till harvest, while Baba sells an F1 (hybrid) cultivar which produces edible spears as soon as 7 months. Once established, the plants can produce spears from 8-20 years.
In cooler climates, it takes longer because of the changing seasons. It goes dormant in winter while its peak growing season begins in spring. Therefore the first harvest can take a few years.
How to grow asparagus from seed
Asparagus is not a plant that is commonly sold in plant nurseries, although you can always try your luck on Carousell if you are not keen on the waiting time. It is however, very easy to grow from seed. If you are wondering how many plants to grow, a rough guide would be a minimum of 5 plants per person. However if you love asparagus, you can consider growing 10 plants per person.
Start by planting the seeds 1cm deep in seed trays or pots filled with seed-starting mix, in a very bright location (if it is exposed to 1 hour of morning or late afternoon sun it is fine). You can create a seed starting mix at home by mixing sifted compost with coco peat and sharp sand (not playground sand) in the ratio 2:2:1. Alternatively you can buy a seed starting mix from brands like Greenspade, Pokon or Baba. Keep the soil moist and do not let it dry out. Within 7-14 days, the seeds should germinate.
When the seedlings are about three inches tall, transplant them into the garden or into planters, spacing plants 30cm apart, in rows 50cm apart. Mulch around the plants to help retain moisture and suppress weeds. I prefer to use coir chips because it doesn’t pose as an obstruction for spears when it is growing out of the soil.
What kind of soil and growing conditions do asparagus plants need?
Asparagus is a sun loving plant and should be grown in well draining soil between the pH of 6.5-7. Water frequently to keep the soil moist, do not let the soil dry out. It is a heavy feeder and benefits from regular fertilisation. A general-purpose fertiliser can be applied religiously to support the plant’s growth.
When the edible spears are around 7-9 inches tall, it is time to harvest. If left to grow much taller, it can turn woody and will not make for good eating. To harvest, simply snap off the spears at ground level, or if you prefer, use a sharp pair of secateurs or a knife. If you are growing many plants and prefer a dedicated tool, you can consider getting an asparagus knife. It forms a clean cut through the shoot at ground level and is effortless to use.
I hope you have found this guide helpful. Growing asparagus is a fun and rewarding experience. With a little patience, you can enjoy delicious asparagus spears from your own garden!