Wonderful Weeds: Our Seasonal Assistants

What if I told you that both the below pictures were taken in Spring within one day of each another, and are located less than 5km apart. Would you believe me?

Now, what if I asked you which soil you think grows the best fruit? Unsurprisingly, most people will say “the one with the flowers!” Well, while we can’t say for sure, it certainly feels that way, doesn’t it?

This photo was taken one Spring when the weeds in our vineyard were blooming. In our vineyard (left), the flowers that blanketed the sleeping vines were bright and alive with colour, and the butterflies and bees were busily humming around them. On the right is a picture of a conventional vineyard. It doesn’t appear to be a vineyard at all. The ground between the rows is hard and desolate, completely absent of any life. No bees, no butterflies, not even a stray bird. The contrast is startling, to say the least, and is unfortunately the sad “norm” of so many vineyards in South Africa during winter and spring.

This desolation is the consequence of herbicides; chemicals sprayed to kill any weeds (and any other living thing) that pop up between the rows. Thankfully, many farmers avoid this type of destruction by planting cover crops. The cover crops help to harness nutrients in the soil and prevent excessive water evaporation. But they also have another more frightful and familiar goal: stop the weeds!

So, why this War on the Weeds? And is it really necessary?

The answer to this question lies in the subjective nature of the term “weed”. Traditionally, a “weed” is defined as an undesirable plant, whether in gardens or crops. However, a plant that is considered a weed in one situation may be purposefully grown in another. Take Stinging Nettle as an example: a nasty, itchy weed? Or a medicinal plant for treating the symptoms of gout, eczema, and diabetes? Or Dandelion: a pesky perpetrator, or a kidney tonic? Well, the answer depends on the person growing it, doesn’t it?

“A weed is simply a plant that grows where you don’t want it to, or which you don’t know what it does” – Billy Hughes

In our opinion, the war on weeds is an outdated practice. As our vineyard has grown over the past 22 years, we have taken a very different approach to agriculture than most neighbouring vineyards. We have dabbled in various forms of plant life to place between the rows, such as common cover crops like rye grass. But eventually, we found that the “weeds” not only did exactly the same job, but also introduced a dimension of life into our vineyard that couldn’t be accomplished with an additional mono-crop like rye grass.

To better understand our vineyard ecosystem, we asked our viticulturist Kevin Watt to help us identify the names and possible contributions of the weeds on our farm, and we were amazed.

1. Flower Power: Natural Pest Control

Being an organic vineyard, we don’t use pesticides in our vineyard. So, we need a little help from nature to keep the harmful bugs at bay. An abundance of flowering plants, like weeds, increases the number of insects (pollinators like bees and butterflies), reptiles, birds, and even porcupines and duikers, that are all natural competition to vineyard pests, and each other, in one way or another. This helps prevent pest epidemics by keeping everything in balance.

2. Roots Rearrange the Soil

The roots of the weeds bind with the soil, preventing erosion. Fibrous root systems can also aerate soil, and create pathways for water to penetrate deeper into the soil, where the vines roots are searching for water deep below the surface. This is particularly good for our clay soil, as it get very hard and makes it more difficult for the vines to find water underground. Weeds help them along by shifting and softening the soil.

3. Low Maintenance Mulch

Some weeds create a wonderful carpet over the soil between the vines in winter. While most people would scowl at this for fear of it drinking all the vines’ water, this may actually optimize the delivery of water to the vine’s roots. By covering the ground, these plants prevent excess evaporation of water, thus allowing more winter rain to penetrate the soil.

Contrary to popular belief, weeds actually pose little competition to vines for water. Adult vines have root systems that stretch down further than one could even begin to imagine, but weeds are not so fortunate. Their roots go deep enough, but they haven’t spent 22 years digging and so, once that water passes a certain depth, the vines have free reign.

4. Compost

The great thing about weeds, when compared to other more commonly used methods of mulching and composting, is that they require little to no help. Weeds are naturally seasonal, and they come and go on their own. When the Swartland summer comes along, they start to wilt and die, depositing an abundance of organic material into the earth that further contributes to the ecosystem.

Here are just some of the weeds in our vineyard, many of which are indigenous:

  • Cape Marigold (Arctotheca calendula)

This indigenous plant’s gorgeous yellow flowers not only house and feed a large number of insects (its juicy leaves particularly attractive for caterpillars), but the leaves create a carpet effect over the soil. Its taproot also helps to ensure aerated and oxygenated soil, and less resistance to the delivery of water to lower soil levels. It can also be useful for capturing nitrogen and preventing nitrate leaching. Then, when the plant dies, it can return some of that Nitrogen mass to the soil by converting to rich hummus. It breaks down quickly in summer, so does not compete with vines in the hottest months.

  • Purple Echium (Echium plantagineum)

This immigrant is quite invasive, but Its taproot means it penetrates deep into the soil, and helps to aerate and loosen it, allowing the access of water and oxygen, especially in compact clay soil like ours. The conspicuous purple colour of their flowers means they are very popular among the honey bee population, pollinators, and insects such as ants. It has been reported to attract up to 35 bees per minute, yielding nectar sugar of up to 300kg per hectare per season.

Others include:

  • Wild radish (Raphanus raphanistrum)
  • Wild mustard (Rapistrum rugosum)
  • Cape Wild Mustard (Sisymbrium capense)
  • Common wild mustard (Sisymbrium thellungii)
  • Yellow sorrel (Oxalis pes-caprae)

 

Fascinating isn’t it? And that’s just the tip of the stem (a little botany joke). Some of these could even be growing in your very own garden at home. If they can contribute to a 27 hectare ecosystem like our vineyard, imagine what they could do for you. Compost for thought 😉

If you’d like to witness them in brightly-coloured action, late Winter or Spring is the perfect time for a Farm Visit when the flowers are blooming and bees are busy. Check out our Tastings page to book.