Ornamental Grasses: How to tidy them up in autumn

Just the other day, one of my former students sent me a picture, asking "what on earth do I do to this monstrous grass?"

Here it is:

Quite a large clump, quite untidy-looking: they didn't know exactly what grass it is, and I can't tell from this photo, but it doesn't really matter, because my advice would be the same, whatever it was.

(It looks like a Miscanthus, judging by the plumes of now-going-brown flowers/seeds, but don't hold me to it.) 

I've had a lot of these types of grasses in my care, over the years - just type "prairie" into the search box, top left of the screen - and they are always a bit difficult to deal with, because in order to make any real difference to their appearance, you have to be quite drastic in your treatment, which may not go down well with the Client.

Once the flowers have definitely gone over (hard to tell from photo if they are brown and dead, or if that's their flowering colour), then there are two options: 

1) Go over the whole clump carefully, and cut each flowering stalk out one by one, tracing them as far back to their base as you can.

Next, rake out the dead leaves/debris using a garden fork.  This entails running the tines of your garden fork firmly and repeatedly through the clump, raking out all the dead bits. I usually start at the base and work upwards, until I've removed a good quantity of dead material: then, once the "tangles" are out,  I rake across, and downwards: in all directions, really, to get out as much debris as possible.

Why do we do this? Dead material harbours bugs, which can damage the roots of the plants: it also encourages moisture, and a thick layer of dead material will stay soggy all through the winter, so by spring you might find that the centre of the plant has rotted away, leaving you with a ring of younger material, and a bit of a bald spot in the middle!

Plus, it looks brown and unpleasant.

If you don't have time or inclination to carefully rake out the dead stuff, move to the other option:

2)  Give it a radical haircut, all over.  Chop it with shears/secateurs into a neat dome:

 

Please note, this is not the same plant as in my student's photo - this one is a Stipa gigantea, Spanish Oat Grass, but it demonstrates the process on an otherwise evergreen grass.

Having cut it right down, you can then easily and quickly rake through to remove the dead material.

Next year it will re-sprout, and at least it looks tidy in the meantime. 

I am still in two minds as to which method I prefer: this drastic method does look a bit "fake" at first, but it is very neat. And very quick. 

The "carefully" method takes ages, and doesn't look much different when you're finished, so you appear to be not giving good value for money.    

Oh, and the radical chop does also give you a chance to check on any smothered plants next to it, and it also gives you the opportunity to check for weeds growing through it.

But it does look a bit drastic....

So it's your choice, as to which course of action to take: if it's in your own garden, then you can do whatever you prefer, and if - like me - you are doing this in someone else's pride and joy, then I find it best to explain the two methods to the Client, and then do whichever suits them best. They are, after all, paying me!

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