A Beginners Guide to the Weeds of Wellington: A Weedy Seedy Sunday

I do really enjoy doing Seedy Sunday Kapiti. There is just so much reward from these community gardener meetings. There are the interesting things people bring in for the swap table, the stories, the great speakers. But most of all it’s just the chance to chat and learn from locals. We had a small turn out today-I blame fine weather, winter colds, school holidays and our spate of earthquakes-but it doesn’t dampen my enthusiasm as I meet such great people and learn so much.

Thanks to everyone who came and special thanks to Darryl for all the interesting info and handouts, Diane for helping out, and Stacey for organising the event and baking cake – you are legendary!

(Note: I forgot to actually upload this post to the website after the event in July. I’m a bit slow at the moment… Sorry)

Weed Cathedral bells Cobaea scandens

Cathedral bells


Darryl Kee works for Greater Wellington Regional Council trying to keep the region’s weeds under control. There’s a lot of misinformation about weeds. Different regions have different rules and unfortunately agapanthus are not on any banned lists. Some of the interesting snippets I took away from his talk:

  • Don’t get into neighbour disputes over weeds – check the facts first.
  • Waikanae and Eastbourne are the epicentres of weeds in Greater Wellington. If they want to know if a weed is in the region, they check there first as new species start to appear in the rivers and parks
  • There are about 30,000 species of plants in New Zealand, 2-3,000 of them are natives. But there are only about 200 that are not allowed.
  • What isn’t allowed is in the National Pest Plant Accord. Propagation, distribution and sale of these 150 species are prohibited. You can however, have them in your garden. You can see what’s on that list here, or order a printed copy.
  • All plants can be controlled manually – it all comes down to time and effort.
  • Good reminder that organic chemicals are still dangerous to use and require the same care as things like Round-up. The organic sprays are really hard on the rubber seals in spray equipment and need to be cleaned immediately.
  • Most chemical sprays don’t work well in home gardens as they are working around lots of other plants. Seed banks lying dormant underground for years also make work clearing weeds very difficult.
  • GWRC are starting to see a larger number of bird-spread weeds – one of the signs of effective pest management. Everything has a consequence.
  • Biological agents are being used in the fight against many weed species. For example, 3 different species of bug are busy munching their way through Tradescantia (Neolema ogloblini, Neolema abbreviata and Lema basicostata). These ‘agents’ can work well but are a slow process, especially in cooler regions.
  • Climbing dock is the most popular weed brought into organised community weed swaps.
  • There was also an interesting chat about flood control and bank stabilisation. Willows and poplars are the go to planting for this but there has been interesting research into getting swathes of ribbonwood, cabbage tree and flax established over a 5 year period.

Pest Plants of the Wellington Region

There is an excellent booklet on this available here (will post link soon – server seems to be out maybe #eqnz)

There are four categories of weeds in the Wellington region

Total control – You can’t plant these

Bathhurst bur

Bathhurst bur

GWRC will control any of these weeds on your land for free. Call them on 0800 496 734

African feathergrass Pennisetum macrourum

Bathurst bur Xanthium spinosum

Blue passionflower Passiflora caerulea

Climbing spindleberry Celastrus orbiculatus

Eelgrass Vallisneria spiralis and V. gigantea

Blue passionflower - Passiflora

Blue passionflower

Madeira vine Anredera cordifolia

Manchurian wild rice Zizaniz latifolia

Moth plant Araujia sericifera

Perennial nettle Urtica dioica and subspp

Saffron thistle Carthamus lanatus

Woolly nightshade Solanum mauritianum

Regional surveillance – Please don’t plant these

GWRC needs to know where these plants are so they can be monitored for any future control work.

African fountain grass Pennisetum setaceum

Alligator weed Alternanthera philoxeroides

Weed Apple of Sodom

Apple of Sodom

Apple of Sodom Solanum linnaeanum

Asiatic knotweed Reynoutria japonica and hybrids

Australian sedge Carex longebrachiata

Bomarea Bomarea caldassii, B. multiflora

Californian arrowhead Sagittaria montevidensis

Californian bulrush Schoenoplectus californicus

Chilean flamecreeper Tropaeolum speciosum

Polypodium Polypodium vulgare

Polypodium fern

Chilean needle grass Nassella neesiana

Chinese pennietum Pennisetum alopecuroides

Chocolate vine Akebia quinata

Delta arrowhead Sagittaria platyphylla

Giant knotweed Reynoutria sachalinensis and hybrids

Hawaiian arrowhead Sagittaria sagittifolia

Houttuynia Houttuynia cordata

Nassella tussock Nassella trichotoma

White edged nightshade Solanum marginatum

White edged nightshade

Noogoora bur Xanthium occidentale

Polypodium Polypodium vulgare

Purple loosestrife Lythrum salicaria

Senegal tea Gymnocoronis spilanthoides

Spartina Spartina spp.

White edged nightshade Solanum marginatum

Containment  – Please don’t plant these

GWRC will control these weeds in specific areas. Any questions call them on 0800 496 734

Hornwort Ceratophyllum demersum


Boneseed Chrysanthemoides monilifera

Evergreen buckthorn Rhamnus alaternus

Hornwort Ceratophyllum demersum

Sweet pea shrub Polygala myrtifolia

Site-led human health and boundary control – Please don’t plant these

These weeds are so widespread throughout the Wellington region that boundary control by landowners is considered the only option. They must be cleared by landowners back to specified distances from a neighbouring property when a complaint is made to the  GWRC.

Banana passionfruit  Passiflora mixta, P.mollissima, P.tripartita

Cathedral bells  Cobaea scandens

Nodding thistle Carduus nutans

Nodding thistle

Gorse Ulex europaeus    

Nodding thistle Carduus nutans

Old man’s beard Clematis vitalba

Ragwort  Senecio jacobaea

Variegated thistle Silybum marianum  

Wild ginger  Hedychium gardnerianum, H. flavescens

Blackberry Rubus spp. (barbed cultivars)    

Hemlock Conium maculatum

Want to know more about weeds in NZ?

You can also take a look at A key for the identification of environmental weeds in New Zealand from Landcare Research.

All you need to know about the biological control of weeds also from Landcare Research.

Weedbusters national weed awareness programme.

And there is an excellent booklet called Plant me instead.