Gunnera not growing as large as past years?

My Gunnera did lousy last year and is showing signs of doing the same this year. What kind of soil do they like and is there a fertilizer that will help them along? I cover them each winter with mulch, water frequently, sometimes spread grass clippimgs around them!

 

Has the lawn which the clippings come from been treated with anything to kill weeds?

 

No nothing like a herbicide used on the lawn, or in the lawn fertilizer?

 

Perhaps they were hit hard for some reason by the cold winter of 2 years ago and are still recovering?

 

What are you describing when you say that you Gunnera is doing poorly? We have two different forms and I might be able to help, just not sure what is going wrong with your plant. They will grow in most soils, just like lots of water.

 

Do they like a PH neutral soil or acidic soil or do they care as long as they have lots of water?

 

Hi Lori,
They do better in a slightly acid soil. We amend around the plants with compost and
manure every year and put on a slow release fertilizer 16-10-10 (Nutricote) in the spring. We keep it watered very well and do turn on the drip irrigation system atleast twice weekly. Ours is beside our pond but cannot retrieve water from that source.
We find that we our watering it atleast every second day during the hot summer days.
The first plant that we had was sold to us as Gunnera Manicata and it grew very well and kept multiplying but did not get the height that we had seen on others. We were told to wait and it may in time.
We ended up talking to a woman on the Island that has many very large ones, which is what we wanted. She said that if it was not that big by now, that it would never be. We purchased one from her three years ago and it gets easily 8 - 10 ft high and leaves 6 ft or better across.
Hope this helps