Ornamental Grasses


I tend to do the bulk of my garden clean up in the fall.  I know, everyone says leave the plants up for winter interest.  I even advocate that for a lot of clients that are around to enjoy their gardens in the winter.  I find I have more time in the late fall to give the majority of my garden a thorough clean up. In the spring, I am very busy at clients’ houses getting their gardens ready for the season.

One thing that I do leave standing in most areas are the ornamental grasses.  I love the colour and height that they add to the landscape in the winter.  The only exception is by walkways and or driveways where snow-blowers are used.  I cut those grasses down as to not interfere and clog the snow-removing machines.

There are a lot of different grasses and thoughts on cutting down grasses.  The majority of the taller ornamental grasses including Panicum (Twitch grass), Miscanthus (Maiden Grass), Pennisetum (Fountain Grass) and Calamagrostis (Feather Reed Grass) are pruned the same.  Using sharp secateurs or hedge clippers (gas, electric, or battery), they are pruned to a height of  4-6” from the ground in early spring while still dormant.  I have had one or two clients come out quite distraught that I was pruning their grasses down, while there was nothing wrong with them!  

 Grasses provide 2-3 seasons of interest and can be a striking addition in any garden.  I love planting them singly and en masse.  Your choice of cutting tool will be dictated by where and how many grasses you have in your home landscape.  Since I have quite a few, to say the least, I use my gas hedge trimmers.  If I have a helper, sometimes I have them hold the grass plant in a bundle halfway while I cut at the base.  

The ideal shape to prune your grasses is a classic button mushroom shape where the center is a little taller than the sides. This allows the inside stems to be supported by the exterior stems.  Afterwards, you can lightly rake the crown if needed.  This is a great time to see if your grass plant needs dividing.  After three to five years in the garden, most grass plants tend to die out in the centre. Some might have gotten too large for their space or purpose in the garden and you may need to divide and transplant.  Well spring is the ideal time for that! You will need some muscle though, especially those who have clay soil.  

Even with the most ideal soil conditions, dividing your grasses is a workout.  I like to divide in clumps of three.  I go for a pie shape, which I know is not the typical garden center looking plant but does very well in the garden.  Once you remove the pieces, put back one clump in the hole and transplant the other two to new sites in the garden or make some friends by giving them away.  You want the soil level of the transplanted pieces to be the same depth of the clump that was removed.  You also want to take this time to remove any of the dead and get rid of it in the compost.  If you are lucky to live rurally and can buy an annual fire permit. It is quite easy to burn the debris of the pruned grasses.  Use caution as they go up very quickly!


- Spring is ideal time for pruning grasses

- Grasses benefit from being pruned to heights of 4-6”, preferably in a button mushroom shape

- Grasses Benefit from being divided every three to five years.

- Grasses die from the centre outwards