Chemical-free weed control for ecological restoration
Category: Garden restoration projects
Clients have engaged us to restore an area of private property which has been neglected either historically due to land use, or more recently due to time or health constraints. These clients have kindly agreed to allow us to publish our photographic record of the restoration.
Since we only began private landscape gardening in January 2023, the changes in these gardens are just beginning.
We have re-activated our little cottage nursery that supplied Council restoration projects and home gardens from about 2004-2006. Hundreds of native seeds fall and grow, even in our own little garden and gravel driveway, so we have been potting them up in recycled pots with roughly-composted wood chip mulch so our garden restoration clients can have free plants for planting season (or earlier if they have a loose soil and are prepared to water them…but Autumn is much easier!)
We are now offering 10-20 plants (depending on size), in a limited range of species – this year we concentrated on kawakawa, karamu, nikau and Carex – free with every 10 hours of gardening or habitat restoration, while stocks last.
We will look after the plants till autumn.
Here’s what they look like at present:
North Shore Wilds nursery plants, November 2023NSW nursery plants November 23
Following the development of the kawakawa fruit observed in earlier posts, I noticed a few ripe fruit on the tree outside this dining room window.
ripening and unripe kawakawa seen through open dining room window
In summer kereru clamber in the taller branches of the tree, alone, in pairs, and one year with a chick, all within a metre of this window.
Fortunately for the kereru, who are far too trusting for their own good, a dog keeps the garden cat-free, and the dog can’t reach this part of the garden.
A low branch outside the window has ripening and unripe fruit overhanging purei (Carex lambertiana)
Above: a fully ripe kawakawa fruit, found half-eaten on the ground, discloses the many seeds within the orange flesh of a single fruit
The wood of the kawakawa is soft, easily pruned to keep this paved path clear.
Wild native sedges and grasses and moss are allowed to cover the earth under the tree, and the smaller plants are allowed to spread to fill the gaps between paving tiles, keeping out most of the dandelions, creeping buttercup and other weeds.
The native kawakawa looper makes holes in the kawakawa leaves.
These holes are said to correspond to the leaves with the strongest medicinal value, perhaps because of substances produced in those leaves in response to the caterpillars eating the leaves.
Another explanation is that the caterpillars know which leaves are the best to eat.
Either way, this 2 square metres of clay is cool and refreshing to look out on through hot summers, hosts a lot of wildlife, lets morning light play on the windows all year round, and, with fallen leaves and twigs mulching the ground naturally, requires almost no attention to stay beautiful and weed-free.
One evening last week, putting out the compost turned into an after-dinner garden wander – a weed to pull out here, a “volunteer” tomato seedling to pop in there – and I realized this is how it will be for the rest of the summer, just like every other year; the cool stillness of evening and gentle sounds of roosting birds keeps me outside till dusk.
For this shade-loving gardener, it has already become too hot for work in the afternoons except under or among big trees.
It occurred to me that there may be people who would like an evening garden ecology assessment, learning session or even their weeding done, when they are home and can collaborate or advise.
For morning or evening garden restoration services, or forest restoration anytime, contact us.
In the 5 months we have been working with some of our gardening clients, they have learned to recognise and make use of the wild native trees, shrubs and grasses that spontaneously grow all over the North Shore, from the soil’s seedbank from former forest and wetland, or from seed and spores brought by birds or wind.
In this time, even small areas of mown lawn, or gardens containing only the common non-native ornamental species, have produced a few tanekaha, rewarewa and kahikatea seedlings, lots of baby Cabbage trees (Cordyline australis), five-finger (Pseudopanax), Karamu (Coprosma robusta) and mapou, (often referred to as Pittosporum, though it is actually Myrsine australis), and numerous native grasses, sedges and creeping ground covers.
Wild tanekaha seedling hidden among Clivia in a small garden of ornamental shrubs
Of course, those who are lucky enough to have a patch of native bush in or beside their garden, and some undisturbed areas of ground, have seen all kinds of forest species emerge and thrive, including native vines, ferns and orchids, and the less common “forest giants” like tanekaha, kahikatea, rewarewa and kauri.
wild karamu seedlings found among ivy and other weeds in a large weedy garden, a small area of which is now being restored to dense wild native vegetation
wild rewarewa seedling discovered while weeding under a Norfolk pine, now protected with some cut ivy and uprooted weeds
For new clients, or as a “stand-alone” service, we provide a 1.5 hour assessment of your garden’s potential for visual transformation and the recreation of diverse native pant communities, solely through plant identification, soil protection and chemical-free weed control.
Our client Michelle has a large front garden on a slope above a quiet road. Around the edges of this garden there are several large exotic trees, and numerous smaller native trees.
Michelle in her garden – transformation begun
When we started working on this garden transformation, the fences on all three sides were overhung by ivy, which had climbed the fences and the smaller native trees on the other side of the fences, and about 10 metres up a large Norfolk pine. There was also some honeysuckle growing through and under the fence, with some remaining beyond our reach on the steeply sloping roadside berm.
Michelle loves walking in the local bush, and dreamed of enjoying some of that ambience in her own large garden. Once she learned it was possible, she became keen to create a shady little bush-walk by converting the lawn and weedy borders of an unused part of her own large garden to a mostly-wild native plant community, solely by weeding, protecting the weeded ground from trampling and desiccation, and nurturing the wild native seedlings that would arise.
lawn behind woodshed, with juvenile wild karamu in foreground
We set about cutting and uprooting as much as possible of the ivy,
oxalis and grass weeds uprooted and/or suppressed with pulled weeds and cut ivy from the fenceline
and cut, uprooted or suppressed the major weeds around the edges.
Weeds turning into rich soil, with a pile of cut ivy foreground left, drying until it can be spread as mulch
A wild mapou juvenile against the fence, mapou seedlings in the foregroundh, and (lower left) a remnant of a large clump of Agapanthus being successively suppressed then uprooted
Hundreds of tree privet seedlings in the borders were easily uprooted while the ground was wet during winter, and larger ones, along with other tree weeds, were suppressed with a versatile pruning technique that leads to the weed-tree’s death over a year or two.
foreground – a newly uprooted Agapanthus (left) and 4 or 5 wild mapou seedlings (centre foreground -yellowish leaves and reddish stems)
at the base of a large Norfolk pine and a young totara, (left) a wild Macadamia seedling being suppressed by pruning, and helping to suppress other weeds, including ivy and Agapanthus which were later uprooted easily
Many native tree seedlings had already arisen wild among the weeds, and were released over a month or so to provide the basis of the new bush garden. As is usually the case, karamu was the commonest wild native,
one of the many wild karamu seedlings found hidden by the invasive and very dominant Blue corn-lily (Aristea ecklonii – suppressed, top left and foreground – later easily uprooted)
but as the hand weeding proceeded over the next few months we also discovered many wild mapou and houpara seedlings, and several rewarewa.
rewarewa seedling, mulched with loose weeds and shaded with cut ivy branch
Today we were thrilled to find two wild seedlings of pigeonwood (porokaiwhiri, Hedycarea arborea).
pigeonwood seedling #1 – newly discovered, mulched and protected with uprooted Agapanthus roots and other weedsclose-up of pigeonwood seedling #1pigeonwood seedling #2 – newly discovered, and protected with mulch of Agapanthus roots and ivyclose-up of pigeonwood seedling #2
We have seldom seen pigeonwood outside of forest reserves. These seedlings have appeared in Michelle’s garden under a large Norfolk pine and young totara, with many species of trees and shrubs nearby, including those that attract birds that feed on berries.
There are no pigeonwood in this or neighbouring gardens, so a bird has fed on pigeonwood somewhere else, then come to Michelle’s garden to eat; perhaps the berries of native karamu, mapou or houpara (five-finger), or the exotic (and invasive) cotoneaster, ginger or Mexican fan or bangalow palms.
These two pigeonwood seedlings germinated among ground-covering weeds including Aristea ecklonii (Blue Corn lily), oxalis, ground-runners of ivy, kikuyu and Veldt grass. Fortunately we had suppressed most of these weeds a few months ago, leaving all the loose weed material as a thick mulch to rot those that did not uproot easily.
left of centre – the two tallest wild karamu seedlings under the totara and Norfolk pine, with cut ivy piled against the fence
Today we were able to uproot most of the remainder of the weeds, and used the newly pulled weeds to mulch a little more of the lawn’s weedy edge. The soil after weeding is a lovely loose loam, full of composted weeds and lawn clippings, making a seed-bed that will support many more seedlings.
However, the soil surface is drying out fast now the prolonged rainy period is over, so we placed handfuls of weed-material around each of the native seedlings, and shaded small seedlings and bare soil (potential seedbeds) with the woody ivy branches which had been cut and piled over the last few months.
The leaves still hanging from the cut ivy branches provide a scattered partial shade, and the woody branches will keep their shape well into summer, providing a “tent-frame” over which other plant materials can be hung once the ivy leaves fall from their branches.
a karamu seedling found wild elsewhere in the garden has been transplanted here in the rich, friable soil formed from decomposing grass clippings and weeds, and now partially shaded by some cut ivy
Not all seedlings survive, especially outside of the shade and protection of a compatible plant community. We hope to update you on the fate of these two pigeonwood seedlings in a future post.
“Hedycarya arborea, commonly known as pigeonwood, porokaiwhiri, and poporokaiwhiri[1] is an endemic tree of New Zealand. Found on both the North and South islands of the country, the tree grows to a height of 15 metres. The leaves are oval shaped with shallow serrations. Ripe fruits turn red and the plant received its common name back when it was assumed that the New Zealand wood pigeon particularly favoured them, based on observations of the birds eating the fruit. It has since been discovered that the New Zealand wood pigeon does not prefer these berries, and tends to eat them as a ‘famine food’ when better fare is not available”.
Chemical-free weed control for two of our major garden restorations has now been completed and those projects now only need monthly maintenance. This means we will have 8-10 hours a week free for an intensive start to one or two new garden restoration projects where some rapid transformation is needed in addition to the longer term transition to a low-maintenance outdoor environment.
Below: the narrow space between house and fence (1.5m including a paving block path, out of view in the foreground) has been transformed from kikuyu, bare clay and weed trees to native shrubs and trees that need only annual pruning to maintain access along the path directly beneath the windows, from where the residents can watch kereru, tui and songthrushes eating kawakawa fruit in summer.
Foreground left is a nikau, about 10 years old and a metre high. Each year for the next 20 years, one of its 2 or 3 new leaves a year will grow towards the house, obstructing the path, but in this seldom-used area it can be pushed aside, or if necessary tied back or even cut off.
Much later, it will present only a single trunk, and each year two or three of the leaves, canopying the path and surrounding garden from above, will fall to the ground and be carried down the back to add to the natural environment (and invertebrate habitat) under larger trees.
There’s nothing more splendid to watch from your kitchen table than a kereru feasting on nikau fruit an arm’s length away, but if the big leaves are not for you you could skip the nikau and just have karamu, kawakawa and smaller shrubs and groundcovers, such as the sedges (Carex lambertiana) shown here. A couple of seedlings planted here have multiplied themselves by both seed and division, and will continue to spread until they cover the ground without further intervention.
Last week, visiting an area we had freed from honeysuckle and other weeds in 2019, we were delighted to see the first flowering of a male kawakawa.
We were surprised to see it mature so soon after we had planted it in 2020 as a 10 cm high seedling.
The same tree is pictured below, then 20-30cm high, in December 2020. Beside it are wild native Weeping grass, toatoa, and (behind, on the remnants of a harakeke shade fence) the common harmless weed “cleavers”.
Both in the wild and in our home garden, we love to see the Kawakawa flowers forming each year, the female trees promising to attract kereru once fruit have formed in early Summer.
We see two distinct forms in the flowers, because kawakawa is one of those trees that can be either male or female. Both produce long thin flower spikes – the tiny dots are flowers -but only the female produces fruit.
The flower spikes of male trees are longer, thinner and upright, like candlesticks. Below are male kawakawa in various stages of flowering:
In contrast, the flower spikes on female trees are shorter and stouter, and in Summer will gradually turn entirely orange to become a soft, juicy fruit enjoyed by blackbirds, thrushes, tui and kereru.
Below are female kawakawa trees with fruit in various stages of development:
kereru have already eaten the riper ends of some of these partially ripe fruit
This year we will try to remember to get a good photo of fully ripe fruit. Finding a whole fully ripe fruit in this tree can be difficult, since at least one kereru checks out the unripe crop each year, visiting frequently thereafter to nibble on a few unripe fruit. Once the fruit reach the partially-ripe stage pictured above, one or several kereru visit the tree many times a day, and spend a lot of time in it eating.
Like the fairytale Ugly Duckling, an invasive weed tree in a hedge will keep you busy, not with feeding but with endless pruning.
Whether you have a driveway border, ornamental garden or a patch of bush, you can reduce the costs of trimming and pruning by accurately identifying the “ugly duckling”. In the photos below, the ugly duckling is a tree privet in a regularly trimmed kohuhu hedge.
We controlled this tree privet for our client by our specially developed technique, which reduces the tree in a matter of minutes, and kills it over a year or so.
Repeat interventions to control the regrowth will take only a minute or two, perhaps once a month for a while, and then less frequently until the tree privet dies, probably within two years. Well before then, the dead trunk will be hidden among the foliage of the hedge.
Our technique kills tree privets up to at least 5m high without chemicals or felling. In our experience so far, it takes 1-4 years for the tree to be very obviously and completely dead.
In the fairytale, the Ugly Duckling grew up to be admired as the beautiful swan it was, but the tree privet becomes increasingly unwelcome as it pushes aside and overtops its plant neighbours. It can even outcompete forest trees in partial shade.
Young tree privet sapling at the roadside banktop of Kaipatiki Stream, (Glenfield), already dominating the understorey of mapou and karamu in a successful 25 year old dense native planting
We often see hedges or shrubberies in which one or several tree privets are being carefully pruned along with the hedge.
While hedge trees or shrubs look neat and become leafy after a trim, the tree privet gets a growth-stimulating trim instead of being eliminated, and is soon sticking out and above again.
Once the misfit is identified, it is usually cut down. But as with many woody weeds, cutting it off near the base creates a bigger problem, for the cut stem produces a dense mass of low branches around and below the cut. These low branches are often even more of a problem than the uncut tree, as they interfere with the surrounding plants, and stick out directly into paths, driveways and lawns.
Our technique was trialled successfully in 2018 in our Gahnia Grove project on the Glenfield Rd margin of Eskdale Reserve, and in 2019 on about 20 tree privets which had invaded the native tree planting along Kaipatiki Rd opposite Glenfield College.
Depending on the thoroughness of the first or follow-up interventions, it takes 1-3 years for the tree to die. Follow-up interventions only take a minute or so.
Save even more by removing tree privets as seedlings
Tree privet fruit are very popular with birds, and a tree privet seed dropped by a bird in a hedge or shrubbery usually grows up unnoticed for a year or two until suddenly it demands your attention by outgrowing the others.
Much time and expense can be saved by identifying and easily uprooting the tree privet seedlings found in gardens or Reserves visited by birds who have recently fed on tree privet fruit.
Older tree privet seedlings less than a metre high are often able to be uprooted easily when the ground is still wet from winter rain.
When uprooting is not immediately easy or would dislodge soil or disturb other plants, we partially break the stems to starve the roots. The whole plant can be easily uprooted some time later, if desired, or left to decay in place (eg in sensitive habitat or unstable slopes).
Large old tree privets already providing shade and erosion control
Tree privet grows very fast, up to at least 20 metres high, and can live for 100 years.
While it is well worthwhile removing seedling and juvenile tree privets where there is alternate vegetation, mature trees need to be assessed individually, as they are providing many functions.
Forked trunkthe two trunks
Above: A number of tree privets that grew up unnoticed in the last 20 years now form an important part of the forest canopy providing essential shade to Kaipatiki Stream
In or beside young native forest, an unrecognised tree privet will grow up to obscure and overtop all but the tallest trees. Once established, it may have become a vital part of the ecology of the site, contributing to water quality, soil conservation, the diet of birds and other fauna, and the health of surrounding vegetation.
Below: fruit on mature tree privets in native forest canopy
Below: tree privet about 10-15m high in native forest beside Kaipatiki Stream, Glenfield. Since native vegetation on the opposite (roadside) bank has not succeeded here due to grass, shrub and vine weeds combined with flooding by both piped and unpiped stormwater, this particular tree privet is one of several along this part of the stream forming the tree canopy, so in addition to feeding birds, this one is providing life-giving shade to protect water quality and freshwater ecology, including native freshwater fish and eels.
