Hello my name is Charlotte, I am the Craft Gardener here at Highdown Gardens.
I have spent much time in August amongst the Irises in the Lower Garden.
There are many at Highdown due to them being one of Sir Frederick Stern’s garden favourites. Is not hard to see why with their elegant tall leaves and flowers in shades of yellow or purple, they have become one of my favourites too. Stern even cross bred species creating hybrids to plant out in trial beds to see how well they performed.
It is time to divide bearded Iris once they have finished flowering, so from the end of July onwards depending on the season’s weather of course. There are a lot of different types of Iris, check which type you have if you are doing yours.
Typically they are divided every three to five years, I have only started at Highdown this year so I don’t know exactly when they were last done, but I can tell from looking that they are very congested and this would benefit them. The purpose is to give each individual more space to grow and help to keep it healthy and perform better. It’s quite a fun garden task, though it is time-consuming.
I use a border fork to gently lift them all from the soil. You are then faced with a prawn-like rhizome with lots of roots on the underside with the tall strappy leaves coming from the topside.
This just needs preparing for replanting, the rhizome itself can be trimmed down to remove the older parts, leaving the healthier and fresher looking growth.
Very small ones can be discarded or potted up until they have grown larger for new stock to plant elsewhere. I did plant a few small ones just to see how they do. The leaves should be trimmed down to keep the energy at the roots and prevent wind damage, the Highdown rabbits have been helping us with this by feasting on them.
Whilst we were doing this, it was a good chance to remove any perennial weeds that we found. We are constantly battling ground elder here, so took the roots out as we went. There are a lot of bulbs such as snowdrops and gladioli underneath the Iris so care was taken to replant these.
After I had dug up a good few Iris, and had a nice clear weeded patch of earth, I spaced out the newly divided plants evenly to replant. They just need the roots to be fully in the soil, the rhizome needs to stay on the surface as it will not flower well or could rot if fully buried.
That’s really all there is to it, I gave them some growmore and water to help them on their way to beautiful blooms next year.
Be sure to come and see them next May and June.
One of our Irises – prawn-like rhizome with lots of roots on the underside with tall strappy leaves coming from the topside – spaced out newly divided plants