HOW MANY OF THESE EVERYDAY GARDEN WEEDS ARE NEAR YOUR PLACE THIS YEAR?

Each year weather conditions, together with rainfall amounts and sequences, lead to variety in the herbaceous weeds commonly found in gardens and on nature strips around the region. Once native plant diversity was altered after European settlement, seed banks of introduced plant species built up in the soil. The seeds wait for ideal germination conditions. I’ve not included grasses (except Wild Oats), though African Lovegrass is rampant on suburban nature strips.  

Species in bold are over-successful this year!

The species listed are those I’ve noticed in north Belconnen. Other areas may report additional or different species. In 2020 these weed species area also present in the territory’s reserves. Plant species are known as weeds when they have no predators, grazers or harvesters to control their numbers. Some species are edible for humans, at least when the plants are young. See The Weed Forager’s Handbook for details.

RED

• Red-flowered Mallow  Modiola caroliniana Horizontal suckering stems
• Scarlet Pimpernel  Anagallis arvensis Occasionally has blue flowers
• Poppy  Papaver dubium Has a capsule where seeds are shaken out
• Sorrel  Acetosella vulgaris Said to favour acid soils. Suckers grow through soil.
• Bartsia  Perentucellia latifolia Crimson rather than red.

PINK

• Fumitory  Fumaria muralis Pinky-crimson.
• Centaury  Centaurium erythraea
• Proliferous pink  Petrorhagia naneuilli  Thousands of seedlings germinating in bush & reserves
• Onion-grass  Romulea rosea  Grass-like leaves from bulbs dug up by Galahs & Cockatoos
• Cranesbill geranium  Geranium molle
• Storks-bill  Erodium species Seed capsules are shaped like a stork’s bill.
• Mallow  Malva neglecta & M. nicaeensis. Very prolific after the rains came.
• Sandspurry  Spergularia rubra Tiny plant likes bare or stressed ground
• Haresfoot clover  Trifolium arvense  Pinkish flowers embedded in fuzziness.
• Willow herb  Epilobium species
• Common vetch  Vicia sativa
• Broomrape  Orobanche minor Pinkish-beige. No chlorophyll. Parasitic on plants’ roots. 

PURPLISH

• Small flowered opium  Poppy Papaver somniferum
• Periwinkle  Vinca major Canberra’s “favourite weed”. Strong suckering stems
• Salsify  Tragopogon porrifolius Huge seed-heads. Seeds blow away like dandelions’
• Paterson’s Curse – Salvation Jane  Echium plantagineum Significant pasture weed.
  Toxic to horses.
• Wild Sage  Salvia verbenaca  Might be mistaken for Paterson’s Curse though more purple than blue.

BLUE

• Creeping Speedwell  Veronica persica  Low-growing small plant.

YELLOW

• Dandelion  Taraxacum Often amongst grass. Flower-heads can have 170 seeds each.
• Flatweed  Hypochaeris radicata  Similar flower-head to dandelion, thinner stalks. More numerous.
• Catsear  Hypochaeris glabra Similar to Flatweed but smaller. 
• Capeweed  Arctotheca calendula Pale yellow daisy-flowers. Massive numbers. Use for daisy-chains!
• Milk Thistle and other thistles.
• Creeping Buttercup Ranunculus repens
• Caltrops Tribulus terrestris  Summer, path-side weed. Spikes of seed-capsules penetrate soles & tyres.
• St John’s Wort  Hypericum perforatum Orange-yellow masses spreading from paddocks.
• Hairy Mustard  Hirschfeldia incana  Lemon-yellow flowers. Cabbage family.
• Great Mullein  Verbascum Thapsus  Tall flower-stem grows from rosette of ‘furry’ leaves.
• Oxalis species  Also other colours. Bulbs are difficult to completely remove.
• Prickly Lettuce  Lactua serriola.  Germinating  prolifically by October 2016.
• Evening Primrose  Oenothera stricta Pale yellow
• Skeleton weed  Chondrilla juncea Appears to have few leaves.
• Goat’s beard  Tragopogon dubius Huge seed-heads. Seeds blow away like dandelions’
• Hop clover  Trifolium campestre Small clover-like cushion-plants.
• Mexican poppy  Argemone ochroleuca
• Pigweed  Portulaca oleracea Germinates in late summer. Succulent-like. Low-growing.

ORANGE

• Californian poppy  Eschscholzia californica Brilliant colour but very invasive.

WHITE

• Common bitter cress  Cardamine hirsuta  Small white flowers. Disturbed ground
• Chickweed  Stellaria media Weak-stemmed spreading annual in veg. gardens etc.
• Mouse-eared chickweed  Cerastium fontanum Similar to chickweed but hairy.
• French Catch-fly  Silene gallica  Increasingly common by 2020.
• Nightshade  Solanum nigrum Has red then black berries when they’re ripe.
• Shepherd’s Purse  Capsella bursa-pastoris  Smallish plant with semi-heart-shaped capsules

BEIGE 

• Fleabane  Conyza bonariensis.  One of several species whose seeds easily blow away.

GREEN FLOWERS

• Ivy  Hedera helix  Has enough berries for birds to spread them. Tough, climbing stems.
• Sticky weed  Cleavers  Goose grass Galium aparine. Weak stems & round capsules fasten-on clothing.
• Petty spurge  Euphorbia peplus  Has caustic white sap. Can grow to 15cm tall.
• Euphorbia species  Popular feature plants which are “going bush” from gardens.
• Common cotula  Cotula australis Tiny plants which grow in spaces on bare ground.
• Fat hen  Chenopodium album  Bluish-green foliage. Tiny, gritty seeds.
• Wild Oats Avena species Grow 1m tall  in good seasons & ripen, being a bush fire risk in reserves.

INSIGNIFICANT FLOWERS

• Wireweed  Polygonum aviculare  Slightly reddish flowers & gritty seeds.
• Dock Rumex  species  Reddish small flowers. Some are native species.
• Plantain  Plantago lanceolata  Blackish blob flower-heads on long stalks. Ribbed leaves.
• Goosefoot  Chenopodium carinatum  Tends to appear in later summer.
• Stonecrop  Crassula sieberiana  Minute succulent of bare ground. May be reddish-orange.
• Chilean Whitlow wort  Paronychia brasiliana Small, lush-looking plants in bare spaces.
• Purple Cudweed  Gamochaeta purpurea & Euchiton species. Greyish foliage.

These weeds are accepted for high-temperature composting at the Green Waste sites…such as Corkhills’ and Canberra Sand & Gravel’s yards.

At home: if the weeds have set-seed put the seed-heads in a black plastic bag to ‘cook’ in the sun rather than putting them in a home compost bin or heap that may not be hot enough to kill the seeds.

Many households now have green bins to which weeds can be added for commercial composting.

 

Rosemary Blemings August 2020.