Introduction: Remove Gorse(Ulex Europeans) With New Zealand Native Bush

About: Just your average non engineer in beautiful New Zealand, solving my seemingly unique problems because I cant find any one else that has.

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This is a system, of natural, Organic and highly effective Weed control for the Gorse plant (Ulex europeans) designed to replace it with regenerating native bush.

Gorse has rapidly become a noxious weed in New Zealand as once again in true human style it was taken from a cold climate to a temperate one with out understanding its life cycle... surprise surprise...

Traditionally the eradication of this weed is managed very poorly by people, for the most part because they want a rapid response, and do not understand both;
--The features of this particularly plant that ensure its resistance to the methods of removal
--The affects of removing a plant from and eco system both long term on the land and on weed control.

This instructable details how to utilise the positive aspects of this plant to become its undoing by using it to nurture and protect native plants until they grow over the Gorse which is not shade tolerant, and thus kills it. The need to use other plants ensures that bare land colonists done move straight back in and take over again, as well as "tying" the land together to prevent erosion

Step 1: 2.)What You Will Need.

- A good understanding of the gorse plant (to follow)
- A good Slasher and file
- Adapted spade (file one vertical side to and edge - great for clearing vegetation from plant sites)
- Strong boots or steel capped foot wear - appropriate to a sharp slasher.
- Optional Fertiliser (ie: magamp)
- Appropriate native plants (see later for source)
- Thick leather gloves (gorse pricks...)
- Portable water depending on environment
- Sharp knife
- Good faith!

More photos to come soon... (For entire instructable)

Step 2: Get to Know Gorse

First we get to know our Weed.

Botanical Name: Ulex europeans
Common Name: Gorse
Family: Fabaceae

Gorse is a very invasive plant happy in just about any soil, it thoroughly enjoys full sun and detests and dies in shade of any kind. The seeds are released by heat (both hot sun and fire) and are catapulted from the plant 2-3 meters, and remain viable in the soil for what some predict is 70 years.

As a member of the Fabaceae family (Nitrogen fixers, which include common plants like the garden pea) it is my understanding that Gorse does have the ability to capture and use atmospheric Nitrogen which is ultimately released to the soil and other plants.

This Nitrogen fixing capacity would also tend to be confirmed by recent research also linking Gorse to assisting in the destruction of our water ways by leeching Nitrogen directly in to waterways] Leeching Nitrogen directly in to waterways)'

Nitrogen is one of the Macro nutrients that all living things require in order to make proteins
(Plants get it directly from the soil, animals via their food.) Nitrogen in particularly promotes lush green growth in plants. (Note the N.P.K on most fertiliser - represents Nitrogen, Phosphorus and Potassium the three macro nutrients)

Introduced in to New Zealand as a hedge / ornamental plant from a cooler climate it soon ran rife in NZ warmer climate. The sharp spines forming the foliage ensure it remains essentially unpalatable to most animals, while its high viability seed and enjoyment of clear sun ensure it spreads and re grows well in bare landscapes

How not to effectively get rid of the Gorse plant!

It appears to be common practice to in the urge for a fast out come to first spray and then burn the foliage, the gorse just loves us for it assisting with its life cycle;

First we spray it - and generally succeed in also removing any other herbaceous plants that may be able to compete after we remove the shade from the gorse bush above it.
Then we burn the dry gorse foliage, they heat of which happily release the fire proof seed and flick it all around in to the soil that we make even more acceptable by a nice coating of ash as mulch. The seed are long viable so have no trouble having a rest and then popping up again next summer.

Step 3: Educate Your Self

However if we take the more long term approach, by copying how nature regenerates land, while it might take 5 - 10 years to control the Gorse completely and 15 years for the desired tree height, you will gain control of the gorse, prevent regeneration of it and at the same time keep your land slip free and healthy.

While requiring a good measure of hard yakka, (it's good for you!) This method essentially mimics how nature regenerated left alone.

The first steps is to educate your self by observation'


How would Nature achieve the same?

If you had all the time in the world to watch your patch of scrub and gorse, and were lucky enough to be close to a patch of native bush, over time you would notice that every plant has a function and a place within the regeneration cycle.

> First the herbaceous grasses, scrub and often weedy plants appear. They capture moisture near the ground and help to build up a nutrient rich compost layer. This tier, doesn't really mind what conditions are present, and often enjoy full sun.

> Eventually this layer will be found by seeds delivered by a number of means, and when the conditions are right for that particularly plant, the seeds will (i.e.: the wind, animals poo, bird drops, run off...) germinate.
This tier will also generally enjoy open conditions and plenty of sun light, while growing on to shade the tier before.

> Next the seeds that like germinating in moist earth, with partial sunlight and low wind will appear; these will ultimately grow up and cover the layer before them, and all the plants that like full sun will start to disappear.

> And so the cycle continues - in mature bush when a large tree falls, you see the destruction of the bush around it and how the cycle often restarts from the beginning.

For the purpose of this Instructable we will simplify and refer to the Tiers of regeneration as;

1.) The colonists (Gorse)
2.) The over colonists
3.) The Sub Canopy
4.) The Canopy


go look at your gorse patch and identify where your gorse is growing in relation to all the other vegetation on the property. You will soon notice that';
-- It grows in the open
-- Tends to die out in the shade
-- That there is often happy looking plants growing in the shade of Gorse
-- That where the land is covered in vegetation, even gorse, there are few to no slips.
-- The grass around the gorse is green
-- And in summer you can clearly hear the "snap" of seed dispersal... count the flowers do the math..

Find a regenerating bush reserve in your area (ask the local parks department where that is)
Take a walk through the area and note the different levels and layers of native plants - ideally you can find an area that has some gorse, low scrub, low, medium and large natives in it, and you will notice that there is;
-- There is lot of young happy looking natives below the gorse
-- Where the natives have grown above the gorse (in particular the ....Tea Tree) the gorse is now looking sick
--Then there are areas of medium natives with natural leaf litter and not gorse underneath
-- Large trees with medium and small natives underneath and no Gorse at all...

That s what we are going to re create - the system of layers of regenerating bush, which simple acts;
- To use the Nitrogen fixed by the gorse to grow the natives under the gorse.
- To allow the colonist species then rise above the gorse (fast growing and shady) and kill it
- To allow the other native juveniles to grow happy in the shade (they don't like to be in full sun or exposed)
- To all the nutrient rich leaf litter (humus) to build up and mulch the ground

Now I think you can see how it all works

Step 4: 3) Discover Your Native Friends.

Identify the Native plants appropriate to your area; this is made easier if you know them by site - so consider taking a plant ID course or doing some swot / rote learning.
You can do this by;
- Look under your Gorse, and around your property and neighbourhood
- Asking your local Council, Park service, Plant nursery.

Learn to identify the weeds and noxious weeds and the different tiers.

So in by example, in my location (Northland - New Zealand)

The colonists of bare, burnt or cleared land are a combination weeds and noxious weeds including;
1) Kikuyu grass
2) Ragwort
3) Thistle
4) Gorse
5) Blackberry

And the Natives are;
1) Bracken fern

The over Colonists Are varied, all though the "work horse plants of main interest to us include;
1.) The New Zealand Tea Tree, Manuka Leptospermum scoparium
2.) Kanuka Leptospermum ericoides)

The Sub Canopy while still including some of the larger trees for the Over Colonists, also includes many broad leaves Natives, all these prefer to start off in partial sun light and help to create a well shaded forest floor excluding the possibility of weeds germinating, and helping retain moisture..
This group includes;
Black fern
Five finger
Lance woods

The Canopy
The final stage of regeneration the slow growing but ultimately the biggest trees which will cover all those before, but love to fight their way to the top and will usually die or struggle germinating in full sun light include;

Step 5: 4)Gathering Your Plants

So once you have established your Over Colonists then you need to first source them, along with your other plants, ready for planting in spring. This will require planning, given that the best time to plant new plants in the ground is towards the end of winter when there is still plenty of rain but the danger of frost is past allowing them to get a little established for the spring growth season.

(You can commence the manual work in winter (no snow here) when its cool and nice to work in.)

There are several options depending on your skill;
> Grow your own - from seed and cuttings in pb pots. (This will require a green thumb or consider a polytechnic propagation course; you will need legal access to seed/cuttings.)
> Collect seed and broadcast (haphazard - and legal access to seed)
> Transplant seedling if you have legal access to regenerating. Bush or farmland on the border
> Source from wholesale nursery.

(Dont get caught taking seed or plant material from Crown land (with out a permit) as this is not only and offence but will prove very costly for you)

Set up a bulk storage area with irrigation; get the plants on site prior to the planting season.
(Instructable to come on this and irrigation and propagation watering)

Ideally they should be at least a year in pots before planting - some where I in the order of 50 - 100cm in height

Step 6: Pre Planting

You need to get your slasher really nice and sharp,(instructable to come on this) and start cutting tracks through your Gorse patch (through being the operative word, as we don't wish to destroy the gorse, only provided access as we are going to use it as a nursery plant for the seedlings)

Cut in a grid pattern, marking them if you required.

Where you have aggressive weed ground cover, such as kikuyu, you may need to do some ground preparation, either manually clearing circles or (spraying out circles 1m with spray and landmark a very good dye so you know where you have been that you mix in the spray.)

Step 7: Planting

Towards the end of winter after the frosts have past, whip through your cut lines, and cut holes. This is best done with a modified spade (see Picture) dig a rough square hole - (four vertical cuts) and deposits the soil close.

Take your plants still in their pots and deposit next to the holes (if you think you wont loose any)

Your priority plants at this stage are you aggressive over colonists (in my case - in Northland New Zealand) that is the Tea tree's- Manuka and Kanuka (Leptospurnum scoparium and ericoides)) but you can add other broad leaves too if available

Decide if you need to use a pre fertiliser in the wholes - magamp is one such. But generally natives are hardy and don't require extra.

>Cut the plastic Pb pot off (or pull off if you want to recycle them)
>Make a cut down the side of the root ball left and right to ensure that roots are not bound.
>Drop in fertiliser (if you choose to) swirl around, cover with 2 - 3 cm earth.
>Drop in the plant; crumble the clod of earth around the root ball, covering no higher than 1cm or so over the root ball, press down with both feet either side of plant.
>Water soaks if you choose - or plan to plant just prior to a good rain storm
>Mulch if you choose to (this is and advantage if you can afford to)

>Return regularly and keep the weeds back, not worrying to much about the Gorse only to perhaps keep the tracks open.

When the plants have taken hold ( and you will loose some) and are starting to get close to busting through the Gorse particularly the Tea tree, consider if you want to go through in early spring and cut back some of the gorse so that in the growth spurt that comes with spring they leap ahead. Doing this however you must be careful not to slash your plants among the Gorse.

Step 8: Success

Monitor the aggressive over colonist, the plan is that they grow up and eventually shade out the Gorse, which dies and can't re germinate in the shade.

By this stage the other over colonists, sub canopy and canopy plants have got a head start in the shade. Just as plants do in the natural order of the forest, during this time they are also depositing leaf matter that helps create the mulch layer and seed in the surrounding soil...

The Tea Tree will eventually die out also - as it doesn't enjoying being shaded to much either but by that time you will have rich native bush in most areas... completely self sustaining..

Success Demonstrated!

I was part of a team that used this method to regenerate native bush on the lower slopes of St Pauls Rock, in Northland, New Zealand. ( between the access road and the summit).. having returned there some 20 years later I was just stunned to see the size of the bush that had grown from those seedlings.. and not gorse or grass in sight!

Step 9: Reference

gorse images: Walter Stahel, Murray Severinsen Environment Bay of Plenty
gorse polluting water ways

Metcalf, 2007, The propagation of New Zealand Native Plants