Save on hedge-trimming costs

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.

Contact details button

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).

Contact details button

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.

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.

Time to act before the Spring rush

Just a reminder that Spring is underway as far as the plants are concerned, and weed vines and shrubs are putting out new shoots, sneaking around garden shrubs, drinking up the lovely water and increasing sun, and finding new ground to conquer.

Big weed invasions yield the most material for paths, mulch and compost, and the first big weeding produces a massive amount of plant material to be either sent to landfill or used to benefit the soil and plants by decomposition onsite.

Once the ground dries, sun comes out, and rain is infrequent, decomposition by rotting slows down or stops altogether.

We don’t encourage storing big piles of dry woody or papery material during the fire season, so if you have a lot of woody weeds to be dealt to….that is, vines, shrubs or trees…work needs to start very soon if you want the plant material composted onsite and returned to your soil to help the remaining plants grow well and remain weed free.

After we have done weed control and mulched where needed, the Spring rush of weeds doesn’t occur for most species, and not at all if we have had time to eradicate the weed before the warm weather.

Instead, the wanted plants grow luxuriously in the moisture and sunlight of Spring, filling the space and reducing weed reinvasion.

Since we only started our business last Christmas, we don’t yet have photos of our clients’ gardens in Spring after our weed control.

Below is a photo of an area of public Reserve in January this year, hand weeded of major environmental weeds, then gradually of benign leafy weeds. This area is part of a forest margin, in which density is key to keeping the area weed-free, so native regeneration has been allowed to fill the space entirely.

Contact details button

Finding the hidden treasures in Tradescantia

A native “Shaking brake” fern sporeling growing in Tradescantia

Almost every gardener knows Tradescantia ( Tradescantia fluminensis, aka Wandering Willie, etc). And many of them see it as a curse.

However, seedlings released from Tradescantia by careful handweeding usually include both natives and invasives, and they flourish in the humus created by decomposing Tradescantia.

The mahoe, toatoa, ti kouka, karamu and karo seedlings in the photos below are just a few of the thousands of native seedlings and sporelings we have found while handweeding Tradescantia in the Kaipatiki suburban area.

It is true that Tradescantia is relentless – though slow – in its growth, covering vast areas if unchecked, suppressing the natural regeneration of diverse native plants in wild habitats.

It is also true that it takes strategy and care to remove it completely and compost it to its extinction.

Above: Dense Tradescantia handgathered into piles for decomposition in place. Handweeding was begun furthest in the background, where the Tradescantia has been replaced by native regeneration 1-2 metres high.

Newly-piled Tradescantia around the cabbage tree is still green, while work has just begun on the area in the foreground.

Both before and after handweeding, Tradescantia’s leaves build up a loose humus-rich soil, and as a moisture-retaining ground cover it nurses seedlings and sporelings, which flourish if they are released to light at an appropriate time, and provided the soil is not allowed to dry out.

The humus and seedlings together provide for perfect regeneration of a native habitat if the Tradescantia is controlled methodically and carefully to its final eradication from an area, which can take a year or two as hidden stems emerge.

Below, June 2020: young toatoa (Haloragis erecta) seedlings, among the remnants and regrowth of Tradescantia after handweeding.

Many of these toatoa grew to a metre high here, helping revegetate a bank left bare by the removal of honeysuckle and dense Tradescantia.

Below, April 2021: The same bank, the toatoa on the right in foreground and midground. The young karamu, mahoe and ti kouka trees survived prolonged drought , sheltered and shaded by the shrubby toatoa that emerged spontaneously after handweeding of a major weed invasion which was followed by Tradescantia.

The image comparison below shows the same area during Tradescantia control in the foreground, as far as the tall ti kouka centre background. (The area beyond was left covered in Tradescantia for a few more years to avoid dessication and weed invasions more difficult to control, such as Creeping buttercup and Paspalum).

Drawing on our experience and photo records of handweeding for ecological restoration, we look forward to illustrating more examples as time permits.

In the meantime, you can see a description of our general methodology here.

Contact details button

Ruru seen at Kendalls Bay

I have been reading up on ruru, after a friend shared this photo of the ruru they saw recently at Kendalls Bay. 

I wondered why it was visible in the daytime, and also whether they need large old trees with holes for their nests. 

Apparently they hunt mainly in the early night and early morning, and sometimes at dusk and dawn, particularly in bad weather. And they nest in any tree large enough to have hollows).

There are some excellent recordings and photos….including one in Hillcrest, and one in Mairangi Bay…at…