Weeds - In Their Defense

I've been reading a great book by Richard Mabey called Weeds.

 

Weeds: In Defense of Nature's Most Unloved Plants

Its a subject that I spend a lot of time thinking about, and if you've been reading my blog for any length of time, you'll know that I have strong thoughts about the proliferation of alien invasive plants.
We have a serious problem here in South Africa, with exotic, alien plants that have adapted to our conditions and are thriving and often out-competing our indigenous plants.

The feelings of peace and joy that most people derive from looking out over a seemingly natural forest valley, for me, can be a truly depressing feeling. At first glance, it may look like a serene, beautiful forest, but under the surface, there is a serious battle going on for space, food, and water...with lives being lost on a daily basis.

Montanoa - A pretty alien that frequents forest edges

That all sounds overly dramatic, and maybe it is...just a touch, but the reality is that even with our internationally renowned programmes like Working For Water, the reality is that these aliens are taking over.

If you consider that nearly 10% of the surface of our country is covered by alien plants, and every season, each one of these plants are producing hundreds of thousands of seeds, you begin to realise the magnitude of the problem facing our country and our natural vegetation. And all this is aside from their obvious threat to our own existence with the potential looming water shortages brought on in large part by these decidedly thirsty denizens.

Having said all of that, its been a refreshing read going through his book and looking at these 'evil' plants through different eyes. Even his attempts to provide a definition of what a weed is, sheds a different light on these tormentors and the symbiotic roles we have in each others stories.

I found the irony to some of his stories both tragicomic and terrifying. The story of the way in which Cogon grass has infiltrated the Southern States of the USA after its indiscriminate use of Agent Orange in the jungles of Vietnam is particularly stinging.

If you have a moment, you should definitely get hold of a copy - its well worth the read.

I've also begun a series on instagram - #invasiveplantsa - in which I've begun highlighting some of the more dangerous yet beautiful aliens. My hope is that by making them more visible, we would all be able to recognise them and do something serious about them.

You can also check out a previous post about the top 6 aliens and what to do about them.

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Exotic Love

I love talking with people who are passionate about what they do. There is so much you can learn from someone who is impassioned by their vocation/hobby/interest. I ran into just such a person the other day at a nursery. She introduced herself, and noticed that I was looking at the indigenous section, and before long we were having an interesting debate about the effect that the indigenous plant movement has had on gardening in South Africa.

Not much beats an indigenous Helichrysum for its spectacular beauty

She felt very strongly that the last decade of emphasis on indigenous plants has had a very negative impact on gardening in South Africa. She talked very caustically about gardening in 'Eco' Estates and pointed out the double standards that exist in the rules and regulations at these estates. She compared the move toward indigenous planting (rather extremely) to Nazism, and also to our unfortunate political landscape, and pointed out that fanaticism in any shape or form is usually unhealthy.

I agreed with much of what she said about the exotic vs indigenous argument:

• Many exotic plants use much less water than some indigenous plants.
• Just because a plant is exotic, doesn't mean that it is invasive or a pest, and in fact some indigenous plants can be hard to get rid of once they are established in your garden.
• Exotic plants are (generally speaking) prettier, with bigger, more abundant flowers.

I also agreed that we need to be careful about extremes of any form, even in the garden industry.  And although I am a firm believer in planting predominantly indigenous plants, I have always felt that there is space for exotic plants in the landscape.

But I think there was something that this plant enthusiast was missing about the ardour for indigenous plants...its more than just a superficial appreciation for the beauty of a plants flowers, its unique shape, or its interesting leaves. There is something 'true' about seeing a plant that is thriving in its rightful place. There is an undefinable feeling I get when I see a plant that fits in with its surrounding vegetation or environment. And while I agree that we need to be open-minded about our plant selection, in most cases an indigenous plant is the 'right fit'.

I walked away from our discussion with a better understanding of the exotic plant enthusiast, but I also left with a more firm love for indigenous plants.

Deadly Dodder

It seems as if my subject matter is heading towards the dark side lately - Poisonous Cycads, and now Creepy Dodder. I promise, its purely circumstantial and no substantive change in direction…

After not having seen any Dodder (Cuscuta sp.) for about 10 years, I've spotted 2 infestations in the last week in gardens that I've visited. If you don't know of Dodder's reputation, then its about time someone passed on its diabolical legend - its really the plant equivalent of a super-villain.

Cuscuta (Dodder)

Dodder is one of the only plants that don't have chlorophyll, and therefore cannot make food from sunlight. You would think this would put it at a disadvantage, but actually, this is where the story takes a bizarre twist into the horror-genre of the plant kingdom.

Dodder is a parasitic plant which feeds on its host plant by entwining its leaves and stem, and then producing haustoria - suckers which grow into the host and then literally suck the life from its limbs. If this isn't scary enough, it also has the ability to grow from even the tiniest fragment towards its next unwitting victim. It doesn't even need to have the apparent crutch of a root system to hold it back.

It appears to have the ability to 'smell' its next victim and grow towards it - with plants surviving about 5-10 days without a host. It also spreads by seed - tiny little pea-sized seeds which germinate very easily.

All these aspects of its incredible design is also what makes it so tough to get rid of. Here are a few simple steps to rid yourself of Dodder:

1. Try to catch it early, the more there is of it, the harder it is to remove.
2. Catch it before it seeds itself - as the seeds can lie dormant for quite a while before sprouting.
3. It is best to place a piece of plastic as close as possible to where you are working to catch all the pieces of the plant that might fall onto the ground.
4. Cut back the host plant well below where the dodder attaches itself, because the plant can regrow from its Haustoria.
5. Ensure that you try to get rid of as much as possible without dropping any pieces.
6. Burn all the traces of the plant, and don't try to make compost from it!
7. Follow up - keep looking for traces of it (Go back to Step #1)

Limestone Fynbos

I was recently contacted by the Duiwenhoks Conservancy to spread the word about a book that they have put together about South Africa's quite unusual Limestone Fynbos.


Limestone Fynbos is an intriguing flora that occurs on South Africa's southern coast, wherever there are limestone hills or cliffs. Most of the plants occur in a broad sweep from Gansbaai to the Gouritz River, including pockets at Cape Point and Macassar. This flora can be divided into three natural units, Agulhas Limestone, De Hope Limestone and Canca Limestone.

Limestone Fynbos of the Vermaaklikheid Area

Limestone Fynbos is floristically very different from other vegetation. The reason for this is that these plants thrive on a soil type that would be toxic to most fynbos plants, which are normally found on acidic or neutral soils.  They grow on limestone soils, which are so alkaline that if you squeeze lemon juice on them they will fizz. It is this alkalinity in the soil that is toxic to most fynbos plants. In a remarkable adaptation to a hostile soil environment, Limestone Fynbos has evolved as a unique flora that shares only a few species in common with sandstone fynbos and sand fynbos. As one would expect from a flora that is confined to such specific soils, many plants are endemic, meaning that they grow only on such soils or even at only one locality.

At first glance, this little-known flora appears as dry woody scrub. On closer inspection a fascinating array of intriguing and sometimes tiny flowers emerge. Over the past ten years, the author Louisa Oberholzer began collecting, describing and photographing the plants in the Vermaaklikheid area of the Western Cape ( Near Stillbaai). The Duiwenhoks Conservancy provided financial support for the identification of the species and finally for the publication of the book, Limestone Fynbos of the Vermaaklikheid Area. It presents a photographic record and description of 124 species. Of particular interest are the intriguing Fabaceae, or pea-like flowers and the pungent buchus, which belong to the Rutacea or citrus family.

The book is priced at R130.00 available from the Duiwenhoks Conservancy, (info@duiwenhoksconservancy.co.za) and also from the author, (louisa.stanford@gmail.com)


This book is an important vehicle to inform the public and particularly landowners about the value of Limestone Fynbos and the importance of controlling alien vegetation, which is a major threat to all the fynbos plant communities. As people see its value, this little known vegetation type will hopefully be better protected.

The Top 6 Aliens To Watch Out For

You didn't expect to see little green men did you? This is a blog about Landscape Design - albeit from a South African perspective...but still...

I've recently joined Sprig as a guest blogger, and have written a post about an extremely important subject for us here in South Africa - Alien Invasive Plants. You may have noticed a few posts about the subject here before. I wrote about the efforts to control them through biological agents, and the differences between exotic and alien plants

Its important to be able to recognise them, so that you can eradicate them as quickly as possible. So here are some pictures of the most dangerous aliens to be on the lookout for where I live - in Kwazulu Natal, South Africa:

1. Chromolaena odorata - Triffid Weed - This plant spreads like wild-fire, because it seeds itself when it is still young, but it is easy to pull out when its still small.

2. Litsea glutinosa - Indian Laurel - I think this is our biggest threat here in KZN. Under a single tree, thousands of saplings shoot up. They grow at a rapid pace, and are difficult to pull out, even when small.

 3. Cardiospermum grandiflorum - Balloon Vine - Grows up into the tops of trees extremely quickly, and spreads its seeds out of sight. Easy to spot and pull out when its still small.

4. Lantana camara - Don't confuse this with the hybrid, which is safe to plant. Easy to uproot when its still small.

5. Melia azederach - Syringa - Like Litsea, it grows quickly and is hard to remove even when small.

6. Schinus terebinthifolius - Brazilian Pepper - It used to be planted as a fast-growing hedge, because of its pretty berries, but soon became a pest.

Now that you know how to recognise them, take a walk through your garden, and pull them out as quickly as possible...

You can also download a pdf list of all the Invasive Alien Plants of South Africa.

Indigenous Beauties : Tapinanthus

While clearing some branches and cutting down an alien invasive Syringa tree, I noticed this amazing plant growing on the branches of the Syringa. It's common name is 'Lighting Matches', for obvious visual reasons.

Tapinanthus
lighting matches

Its a type of mistletoe, and is hemi-parasitic. This means that it uses the sap of the host plant that it is attached to, as well as creating its own energy from photo-synthesis. In most cases it won't kill its host, but if in abundance on a single tree, it may weaken its host, making it prone to diseases.

It is spread by birds which eat and regurgitate its extremely sticky fruit, the fruit usually lands on a branch, which then attaches itself by sending out 'roots' into the branch.

The fruit is also used to catch birds, by being chewed into a sticky pulp which is then spread on the branches of trees. Birds get stuck to the glue, and are then quite easily caught.

It is not easily spotted, as it blends well with its hosts leaves. However in winter when the host loses its leaves, and it begins flowering it is quite easy to see.

It might be a great environmentally friendly way of dealing with the Syringa I need to cut down - spread enough of the Tapinanthus onto its branches, and weaken it, so that it eventually dies on its own?