Kikuyu Grass and a chicken

How I keep the Kikuyu Grass out of my garden.

Kikuyu Grass and a chicken
Stopping Kikuyu grass invading is a constant battle and to be honest – chickens aren’t up to the job!

Out here on the coast the sandy soil is pretty much held in place with the kikuyu grass, especially on the hills and I have no problem with this.  The last thing we need is erosion or even worse – a blow out, where the wind whips away the sand causing a deep hole.  Once you get a blow out it can be difficult to get it back into control as the lack of substance in the soil and the constant wind creates a bigger and deeper hole.

Kikuyu Grass on coastal hills
The Kikuyu Grass does a great job of holding the sandy coastal hills together.

Our lawn is also Kikuyu grass and we enhanced what was already here by sowing seed!  We have a lovely spongy lawn that stays green for most of the year, but when there is a drought it will brown off but comes back quickly with that first rain.  But I also have a massive garden that I do my best to keep weed free and with Kikuyu Grass surrounding it on all sides it can be a bit of a constant battle to keep the creeping runners from encroaching into the garden, but after five years I can confidently say I have an effective barrier system of protection.

Kikuyu Lawn
We have such a lovely kikuyu lawn kept in tip top shape by Blossom, my Gardena Robotic Lawnmower.

The first and most important thing is to make sure the ground is completely free of Kikuyu – roots and all, before you start.  I had the benefit of getting the help of a tractor to scrape the soil bare.  If you want to dig, then a slow and steady approach, doing a small amount at a time in a thorough and methodical way will get you there.  The good news is you don’t need to dig to China.  The runners form a thatch above and below the soil that is only about 30 cm deep.  But you need to get every last bit of runner.   Whatever you do, don’t use a cultivator as this will just chop them up and make a million more plants.   The runners can regrow from the smallest shoot.

Clearing Kikuyu grass with a tractor
This has to be the fastest and easiest way to get rid of the Kikuyu grass but I appreciate not everyone has access to a lovely neighbour with a tractor.

A good thing I have found with Kikuyu is if you leave something sitting on it to block the light the vegetative grassy bit quickly dies back to leave a bare patch.  This is handy if you want to clear the land by putting a heavy cover over it, such as black plastic or cardboard.  It’s not so great on the lawn though.  Although it does grow back quickly as the roots and runners are still there, but it gives you an easier area to work with if you are doing the clearing by hand.

Blocking out the Kikuyu Grass
Sheet mulching is a good option to help an overgrown plot to die down, but it is only temporary as it can grow back quickly once the cover is removed.

Once you’ve cleared the land, leave it for several weeks and any bits that you have missed will start to pop up like little green flags.  So, you can just pull them up from the loose soil.  Once there aren’t any more popping up, you are good to go.

Clear Light weed barrier
This was an affordable solution to keep the kikuyu out of one of my gardens. It works quite well but doesn’t stop the annual weeds that blow in from elsewhere!

But to stop them encroaching into your lovely clean soil requires regular attention.   You can create a barrier – something about 40cm will work and there are things out there you can buy.  Or you can get creative and see what you is around.  In one of my gardens, I created a barrier by cutting some sheets of ClearLight roof material – the cheapest one, and inserted it into the garden to separate out the clean side and the wild side.  This still does need attention as the runners can climb over the top – but they are easy enough to remove with a gentle tug.

Hoeing weeds
Regular attention to the weeds in a little and often approach helps keep things under control. If we only get 90% of the weeds this week, no worries because next week we will get 90% and a good dent will be made over time.

For the majority of my garden there is no barrier.  The main garden has a fence, but it was never designed to keep out the Kikuyu so is not very effective other than keeping the long blades from drooping across the edge of the garden.    In this garden I hoe the sandy paths once a week to nip any weeds in the bud.  If I encounter any green flags of the Kikuyu trying to bust through, I pull them out.

Clear fence line
A regular weed and occasional deeper dig along the fence line keeps the Kikuyu at bay.

Sometimes it requires a bit of a dig about with a fork to loosen the soil and make it easy to pull any underground runners back all the way to the fence.  Any overland runners get clipped off at the fence with a sharp pair of secateurs.  This weekly approach works well, but if I leave it 2 or 3 weeks due to busyness, it is still a simple task.

Kikuyu invading no man's land
I have to admit I have left this area a little too long and the kikuyu runners are beginning to creep in.

In the newest garden, I tried something different.  I kept a spades width around the garden free from any plants or mulch and that is my barrier there.   I have to confess I have left it a while – too long, and the runners had snuck across the no man’s land and was popping up in the actual garden.   So, over the last few weeks I have been working my way around this garden strip and with a fork and a pair of secateurs I have loosened the soil and pulled out the long runners and cut them back to the edge of their boundary.

Clear weed free barrier
It hasn’t taken much effort to clear the no man’s land down to a spades depth and stop the encroachment so the garden stays grass free.

To be honest this has taken a wee while as it has been too long since it was last done.  But the time consuming bit is the size of the garden and not the actual work.  So, I set myself up with a podcast and just work until it stops.    Once I get it finished, it will be popped into a maintenance schedule where at least once a week I will hoe the no man’s land to stop normal weeds and pull any Kikuyu shoots.  But once I month I’ll loosen the soil with a fork and rummage around in the soft soil to find any sneaky runners trying to breach the divide.

So, the key points to keep on top of kikuyu are:
  • Start with a clean soil, and you really can’t skimp on this stage, or you will be wrestling with the grass in the garden, and it will be harder to remove.
  • Take a ‘little and often’ maintenance approach to put a stop to anything trying to sneak into the garden.

I hope this helps someone out as Kikuyu can be such a pain to deal with in the garden.

Come again soon – #MakeMayCount is still going well (it is only day 3!)

Sarah the Gardener : o)

7 thoughts on “How I keep the Kikuyu Grass out of my garden.

  1. Hi Sarah,

    I saw your comment re leaving your kumara in their bed last month so have done the same with my first ever crop. I bought a Countdown kumara and sprouted it a little late, back in December, then chopped tuber and sprouts up and placed them in three rows in my garden. The rainy January we’ve had was perfect and they all survived.

    I read on google that when the leaves turn yellow is the time to harvest so nervously hunted around underneath a few yellow leaves and guess what! A respectable yellow kumara 15 x 5 cm! The rest of the plants are still green though, so wondering do I wait for them to turn yellow before looking for any more. I’m not expecting any frost here in Pukekohe for a couple of months so think plants and tubers should be ok?

    Also according to google you need to dry and mature them before eating as otherwise they taste starchy rather than sweet. Do you have any advice on this, I’m thinking I could perhaps string up some netting from the rafters in the garage to protect my harvest from rodents. Would this be warm enough now that temps are slowly beginning to drop or do I harvest in stages and bring indoors to dry and sweeten. What do you think?

    Fi the freshman gardner

    1. Nice job! Mine still aren’t showing more than a hint of yellow, so I’m still deciding when to dig them up – we don’t get frosts here at all. I may have to have a bit of a poke to see what I have. You should harvest on a dry day (hopefully we get one soon) before you do get a frost. Don’t leave it too long as they can rot in the soil. The should be ready any time from 100 – 150 days from planting. Take care as if they get broken they won’t store well. They need to be cured so they keep for a long time. This seals the skin, but also helps sweeten them up. Lay out in a single layer somewhere warm and dry for about 5 days. Don’t wash them – just brush the dirt off. Then pop them in box somewhere dark, cool and dry – same kind of place you would keep your pumpkins. Maybe in a dark sack if you are hanging them from the rafters, but not plastic. Check often for any that might go soft or rot. I hope this helps. : o)

    1. A generation or two ago it was just sand dunes with low fertility so it is a mix of natural succession and farmers trying to improve their land. There are other plants in the hills like marram grass, gorse, boxthorn and native muehlenbeckia among other things and so the land is quite stable. : o)

  2. Hi Sarah,

    Having grown up in Nairobi, I was highly amused to learn that Kikuya grass was present here in New Zealand! One additional tip that for keeping on top of it is homemade vinegar-based weed killer. Mix white vinegar with a few drops of dish soap and spray it directly on the Kikuyu grass. It’s an eco-friendly and cost-effective way to target those stubborn patches. Best to do this on a sunny day for better results. 😊

    Thanks and all the best.

    1. It isn’t a native but has its uses, especially in coastal areas. It just isn’t garden friendly. I would need a lot of vinegar to keep mine under control and I don’t really want to upset the pH balance of my soil that way but thanks for the tip! : o)

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