Pineappleweed

How to recognise it

Growth habit

Low annual plant of 5–30 cm, branched from the base, upright or somewhat spreading. Hairless and rather fleshy, with a strong pineapple smell when crushed.

Leaf

Two to three times pinnately divided into narrow, thread-like segments; bright green and hairless.

Flower

Cone- to egg-shaped heads of 5–9 mm, greenish yellow, made up only of disc florets, without white rays. The base of the head is hollow. From May to September.

Fruit/Seed

Tiny ribbed seeds of 1–1.5 mm without a pappus. When wet they turn slimy and sticky, so they cling to shoes and tyres.

Roots

Short, tough taproot with fine side roots; the plant is fairly easy to pull up.

Confused with

Scented mayweed (true chamomile) has white rays and a hollow head base; scentless mayweed has white rays, a solid base and hardly any smell; stinking chamomile smells unpleasant. Tansy also has button-like yellow heads, but is a tall perennial. Pineappleweed: no rays, little greenish-yellow cones and a pineapple smell.

Flowering: May–September · Pruning: August–September

Why grow it?

• A true pioneer: it grows on compacted, bare ground where almost nothing else will, and keeps that ground covered.
• The flower heads give some nectar and pollen to small flies, hoverflies, little beetles and small solitary bees. Its value for insects is modest, though.
• Flowers all summer, from May to September, even where people walk or drive every day.
• The pineapple scent makes it fun for children and for a fragrant gravel path: you smell it with every step.
• The dried flower heads were once used, like those of true chamomile, to make a herbal tea.

Pineappleweed: where does it grow best?

• In the wild on trampled and disturbed ground: farm tracks, farmyards, car parks, field gateways, verges, pavements and between paving stones.
• Full sun; in shade it stays spindly and flowers little.
• Tolerates compacted soil, poor to rich, from sand to clay, dry to moderately moist.
• In the garden it belongs in a gravel path, between stepping stones, along the edge of a drive or in a bare, sunny corner, not among tall plants that crowd it out.

Goes well with

• Greater plantain: Another tough plant of trodden paths and farmyards.
• Knotgrass: Creeps over the same compacted ground and flowers at the same time.
• Daisy: Little white flowers along path edges and in a short lawn.
• Wild thyme: Another scented plant for a sunny gravel path, and excellent for bees.

Pineappleweed: when and how to plant it?

1. Usually you don’t need to do anything: pineappleweed arrives by itself, with seed on shoes, tyres or imported soil.
2. If you want to give it a place on purpose, sow in March–May with seed from a nursery or seed supplier for wild plants, or seed from your own garden.
3. Scatter the seed thinly on an open, firmly pressed spot and cover it barely or not at all: it needs light to germinate.
4. Keep the soil moist until the seedlings are up; then thin to 10–20 cm between plants.
5. In the first year let a few plants finish flowering, and after that it will self-seed.
6. Never take plants or seed from nature reserves: collect seed only in your own garden or with permission.

Care

Water

Not needed, except for seedlings in a dry spring. It copes well with drought.

Feeding

Don’t. On rich soil it grows larger, but other plants then crowd it out.

Trampling

It handles it perfectly: on a path it stays low and compact, and gives off its scent every time you walk over it.

Spreading

In the vegetable patch or border, pull unwanted plants before they set seed. A layer of mulch on the beds slows germination.

Letting it seed

On a path or in a bare corner, let a few plants finish flowering: as an annual it survives only through its seed.

Tip: Let pineappleweed grow in the cracks of a gravel path or between stepping stones: every time you walk on it, you smell pineapple.

Pruning and mowing

Pruning months: August–September.

When: In August–September, if you want to stop it self-seeding too much.

How:

• Pull up spent plants before most of the seeds are ripe, if you want fewer seedlings.
• If you want to keep it, leave some of the plants until the seed has dropped.
• Dead plants can go on the compost heap, preferably before the seeds are ripe.
• On a path there is nothing to do: trampling keeps it low by itself.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Seed

Pineappleweed spreads only by seed. Sow in March–May on an open, firm spot, without covering.

Self-seeding

Let a few plants drop their seed. In spring keep the seedlings that are in a good spot and weed out the rest.

Pineappleweed: how does it get through the winter?

Hardy to −25 °C.

• Pineappleweed is annual: the plants die in autumn, after setting seed or at the first frost.
• The seed overwinters in the soil, stays viable there for a few years and germinates in spring.
• Late-germinated seedlings can survive a mild winter as a small rosette.

Diseases and pests

• Too many seedlings: In the vegetable patch and border it can come up in masses on bare soil. Weed early, hoe in dry weather and cover the soil with mulch.
• Disappears by itself: Among tall plants or in a dense lawn it doesn’t last long. Give it a bare, trodden spot.
• Confusion with true chamomile: If you want chamomile for tea, look for the white rays of true chamomile. Pineappleweed never has them.
• Aphids: Sometimes there are aphids on the stems. Usually ladybirds and hoverfly larvae deal with them; leave them be.

Through the year

• March: First seedlings on paths and bare ground. You can sow.
• April: Sow on an open, firm spot in the sun.
• May: First greenish-yellow flower heads.
• June: Flowering. Crush a head: pineapple scent.
• July: Full flowering. Pick flower heads to dry.
• August: Flowering and setting seed. Pull up unwanted plants.
• September: Last flowers. Clear spent plants or let them self-seed.
• October: The plants die off; the seed stays in the soil.

Did you know?

• The scientific name discoidea refers to the flower heads, which consist only of a ‘disc’ of tube-shaped florets, without white rays.
• The seeds become sticky when wet. That is how they travelled on cart wheels, shoes and later car tyres, and why the plant grows mainly along roads and paths.
• Despite lacking white ‘petals’, it belongs to the same genus as true chamomile.