How to Grow Black-eyed Susan (Rudbeckia) from Seed in Malaysia
How to grow black-eyed Susan (Rudbeckia hirta) in Malaysia: surface sowing, sun, drainage in the rainy season, deadheading, mildew and pests.
- Difficulty
- Easy
- Days to harvest
- 70–90 days
- Updated
- 2026-11-05
Yes, black-eyed Susan (Rudbeckia hirta) grows well in lowland Malaysia. It is a cheerful, heat-loving daisy with golden-yellow petals around a dark brown centre, and it usually starts flowering about 70–90 days after sowing. The one tip that matters most: its seeds need light to sprout, so press them onto the surface and do not bury them. After that, give it full sun and soil that drains fast, because it handles heat well but hates wet feet in our rainy season.
Quick facts
| Item | Black-eyed Susan |
|---|---|
| Sun | Full sun, 6 hours or more |
| Sowing depth | Surface sow; press in, do not cover |
| Germination | About 7–14 days |
| Spacing | Thin to 5 cm in trays; 30–40 cm between plants |
| Days to first flowers | About 70–90 days |
| Container | 25–30 cm pot per plant, or a large trough |
| Support | Usually not needed; tall plants in windy spots may need a stake |
What to expect in Malaysia
In cooler countries black-eyed Susan is a short-lived perennial. In our lowlands most plants behave more like a long annual: they flower well for a few months, then slowly get tired, especially after long wet spells. Plants reach about 40–80 cm tall. The flowers last a long time on the plant and in a vase, and bees and butterflies visit them often. For colour all year, sow a small new batch every 3–4 months.
It is grown as an ornamental. The pack label says "Vegetable Seed" as part of the general pack design, but this is a flower, not a food plant.
Choosing a spot and container
Choose your sunniest place: a bright balcony railing, a rooftop, or an open bed in a terrace-house yard. With less than about 5–6 hours of direct sun, stems stretch and you get fewer flowers.
In pots, use one plant per 25–30 cm pot, or space several 30–40 cm apart in a long trough. Make sure every container has drainage holes. In the ground, a slightly raised bed is best, especially if your soil holds water after rain.
Soil and potting mix
Black-eyed Susan is not fussy about fertility, but it needs drainage:
- 2 parts garden soil or potting mix
- 1 part burnt rice husk (sekam bakar), perlite or coarse sand
- A handful of compost
Avoid very rich mixes. Too much nitrogen gives big leafy plants with soft stems that flop in storms.
How to sow black-eyed Susan step by step
- Prepare a tray. Fill a seedling tray or small pots with fine seedling mix and water it well so the surface is evenly damp.
- Scatter the seeds. Sprinkle them thinly over the surface.
- Press, do not bury. Press the seeds gently into the mix with your palm or a flat piece of wood. They need light to germinate, so leave them uncovered.
- Keep damp in bright shade. Place the tray in bright, indirect light, out of hard rain. Mist when the surface starts to look dry. A clear cover helps hold moisture; open it daily.
- Watch for seedlings. They usually appear in about 7–14 days.
- Thin. When seedlings have true leaves, thin them to about 5 cm apart so each has room.
Black-eyed Susan Seeds
Golden daisies with dark brown centres — an easy, heat-loving bloomer for sunny beds and big pots.
Transplanting
Transplant when seedlings have 4–6 leaves. Move them into their final pots or bed, 30–40 cm apart, in the late afternoon. Water well and give a day or two of light shade, then full sun. Good spacing is not just for size: air moving between plants keeps the leaves drier and reduces mildew.
Watering in hot and rainy weather
- Hot, dry spells: water every 1–2 days, when the top 2 cm of soil is dry. Established plants cope with short dry periods.
- Rainy season: skip watering while the soil is still wet, and check that pots drain freely. Standing water causes crown and root rot.
- Water at the base in the morning so the hairy leaves dry quickly.
Feeding
After transplanting, give a light, balanced liquid feed every 2–3 weeks at the label dilution. When buds appear, a feed slightly higher in potassium supports flowering. Weaker and more often is safer than strong and rare.
Common problems and pests in Malaysia
- Powdery mildew. White, dusty patches on leaves in humid, still air. Space plants well, water the soil not the leaves, and remove the worst leaves. A weekly spray of diluted neem oil or baking soda solution can slow it; test on a few leaves first.
- Leaf spot. Dark brown spots, often starting on lower leaves during long rain. Pick off spotted leaves and clear fallen debris.
- Crown or stem rot. The plant wilts from the base even though the soil is wet. Improve drainage; remove and replace badly affected plants.
- Aphids. Clusters on buds and stem tips. Rinse off with water or spray diluted neem oil or mild soap solution.
- Caterpillars and beetles. Holes in petals and leaves. Pick them off in the evening.
- Snails and slugs. They chew young transplants after rain. Hand-pick at night.
For more organic fixes:
Deadheading and cutting flowers
Cut off faded flowers just above a leaf or side bud. This keeps the plant tidy and pushes it to make new buds instead of seed. For a vase, cut stems in the morning when the flowers have just opened fully, and change the water every day or two.
When a plant becomes woody, spotted and shy to flower, pull it out and replace it with a new batch of seedlings. If you want to save seed, leave a few healthy flower heads on the plant until the centres turn dark and dry, then rub the seeds out and store them somewhere cool and dry.
FAQ
Why did my black-eyed Susan seeds not come up? Most often they were buried too deep. Press them onto the surface and keep them damp in bright light.
Can it take full Malaysian sun? Yes. It loves heat and sun. Its main weakness is soggy soil, not sunshine.
Why do the plants look tired after a few months? That is normal in our climate. Lowland plants usually decline after a few months of flowering, so plan to resow regularly.
What grows well beside it? Other sun lovers such as marigold, cosmos and sunflower make a bright, easy border: