How to Grow Punarnava (Boerhavia) and Tell It From Its Twin
You may already have punarnava. This creeping monsoon weed pops up on lawn edges, vacant plots and roadside dust across the plains, and many gardeners pull it without a second look. So learning how to grow punarnava plant starts with identifying it properly, because a common lookalike grows in exactly the same places. After that, it is close to effortless: a sunny pot, a monsoon start, and very little water.
Punarnava in brief
- Plant: Boerhavia diffusa (punarnava, spreading hogweed), a spreading perennial herb
- Start: June to August from seed, cuttings or a dug up wild plant; February to March also works
- Pot: wide and shallow, 12 inches across (about 8 to 10 litres), or a hanging basket
- Mix: 2 parts soil, 1 part sand, 1 part compost
- Sun: full sun; it handles 45C heat
- Harvest: leaves anytime it is growing; roots from plants a year or older
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How to identify punarnava
- Stems: long, trailing, often reddish or purplish, swollen at the joints, lying flat or rising at the tips.
- Leaves: in opposite pairs where one leaf is clearly bigger than the other; roundish to oval, green above and pale whitish beneath, sometimes with a wavy, pinkish edge.
- Flowers: tiny, pink to purplish red, bunched at the end of long, thin, branching stalks.
- Fruit: small, ribbed and sticky; it clings to clothes and animal fur.
- Root: a thick, fleshy taproot, which is why it bounces back after being cut down (punarnava roughly means “renewed again”).
The lookalike: horse purslane
Trianthema portulacastrum (horse purslane, sold as bishkhapra in some markets) shares the same fields and has been a long documented substitute in the herb trade. Tell them apart this way:
| Feature | Punarnava | Trianthema |
|---|---|---|
| Leaves | Thin, pale under, unequal pairs | Thick, fleshy, succulent |
| Flowers | Clusters on long thin stalks | Single, stalkless, tucked in leaf joints |
| Fruit | Sticky, clings to cloth | Small capsule with a lid, not sticky |
The trouser test
Walk through a patch in late monsoon. If small sticky seeds hitch a ride on your shalwar, and the flowers above sit on long thin stalks, you’ve found punarnava. A plant with juicy, purslane like leaves and flowers pressed against the stem is the lookalike.
Ways to start a pot of punarnava
Transplant a wild plant
- Choose a plant from clean ground, away from drains and roadsides.
- Water the spot the evening before, then dig deep to keep as much taproot as possible.
- Pot it at the same depth in the sandy mix and water well.
- Give shade for four or five days; it may drop leaves and then regrow.
From stem cuttings
- Cut 15 cm stem pieces with at least two nodes in the monsoon.
- Lay the lower node on moist soil and cover it lightly, or push the stem in 4 cm.
- Keep moist in light shade; roots form within two to three weeks.
The node pinning trick is the same one shown in our herb cuttings guide.
From seed
Collect the sticky fruits when they turn brown, sow them shallow in June or July, and keep damp. Germination is patchy; cuttings or transplants are faster.
Where it grows, by zone
| Zone | Verdict |
|---|---|
| Karachi, coastal | Easy all year |
| Multan, Sukkur, Bahawalpur | Thrives in heat; one of few herbs that does |
| Lahore, Faisalabad, Delhi | Easy; dies back in cold, regrows from the root |
| Islamabad, Peshawar | Summer to autumn; tops die in frost |
| Hills | Lower valleys in summer only |
Care: less is more
- Water: when the top 3 to 4 cm is dry. In 45C weeks, every day or two for pots; in winter, once every week or two. Soggy soil rots the root.
- Soil: sandy and free draining; see potting mix ratios.
- Feeding: a handful of compost in spring and monsoon. That is all.
- Trimming: cut trailing stems back by half to keep it compact; it regrows quickly.
- Spread: deadhead if you don’t want sticky seeds everywhere.
Pests rarely bother it. Mealybugs at the root crown in dry pots and rot in waterlogged ones are the main problems.
When to harvest punarnava
Pick leafy stem tips any time the plant is actively growing, taking no more than a third at once. In parts of India the young leaves are cooked as a saag, which is a food use. Roots are dug from plants at least a year old, after the monsoon, which ends that plant, so keep a few pots going. Wash well, dry in shade until brittle, and store in a closed jar.
Its use in Ayurvedic tradition, and why swelling always needs a doctor first, are covered in our punarnava and swelling post.
Identify carefully: the lookalike Trianthema is not the same plant. Never harvest from roadsides, drains or sprayed fields. Swollen feet, puffiness or reduced urine can signal heart, kidney or liver problems and need a doctor, not a herb; anyone with kidney or heart disease, on water tablets or blood pressure medicine, pregnant or breastfeeding should ask their doctor before using punarnava in any form. Keep pets from grazing it.
Grow it or skip it?
Grow it if you have a hot, sunny pot or basket and want a tough, low water plant that is easy to identify once learned. It is ideal for Multan and Sukkur, where most herbs give up. Skip it in a damp, shaded corner, or if sticky seeds on pets annoy you. More plants in Kitchen Garden.
Punarnava growing questions
Where does punarnava grow naturally?
On waste ground, field edges and roadsides across the plains of Pakistan and India, especially after the monsoon rains.
How do I identify punarnava?
Look for reddish trailing stems, paired leaves of unequal size that are pale underneath, tiny pink flowers on long thin stalks, and sticky fruits.
Is punarnava the same as horse purslane?
No. Horse purslane (Trianthema) has thick, fleshy leaves and stalkless flowers in the leaf joints. Local names overlap, so check the plant rather than the label.
How do I propagate punarnava?
Transplant a wild plant with its root, or root stem pieces in moist soil in the monsoon. Seed works but sprouts unevenly.
Can punarnava grow in a pot?
Yes. A wide, shallow pot or hanging basket with sandy mix suits its trailing habit.
Does punarnava come back after winter?
Usually, yes. The tops die in frost, but the thick root resprouts in spring in the plains.
Red punarnava vs white punarnava: which is which?
Ayurvedic texts describe red and white types. Boerhavia diffusa is the common red flowered plant; the identity of the white type is debated.
How often should I water punarnava?
Only when the top few centimetres dry out. It is drought tolerant, and overwatering is the most common way to kill it.