Growing Gunnera

Gunnera is one of my favourite waterside plants.

Unfortunately, it is not hardy in my garden being rated a USDA zone 7 hardiness.

I have seen specimens in Ireland that easily top 5-7 feet tall and almost the same sized plants out in Vancouver, Canada. In my garden - they have reached 3 feet tall.

However having said all that - where there’s a gardening will - there’s a gardening way.

Growing Gunnera

This plant demands constant and even moisture to succeed. It does not appreciate being dried out so stream side or pond side in a bog is the place for it.

They want full sunshine or very light shade. Don’t even consider trying to grow this plant in the shade.

An organic soil - one high in peat moss or organic matter of any kind - is best.


Fresh seed sown in the early spring will germinate quite quickly at a soil temperature of 70F.

The plant is easily divided in the very early spring.


Not usually a problem. You’ll see insects on Gunnera but because it is so large and fast growing, as long as you protect the initial growth from slugs, you’ll be fine.

Pot Culture

Yes. You can grow Gunnera in a pot if you give it good organic soil and a rather huge pot. It still wants lots of sunlight and even moisture. (Let it sit in the pond so the bottom of the pot is “just” in the water). It does not want to be waterlogged so do not let the crowns sit in the water. You have to think that the bottom of the roots want constant dampness and the soil has to be damp but the roots themselves do not want to sit in the water. This is not a water plant but a water-side plant.

Feed weekly with fish emulsion for best growth rates.


Gunnera is not particularly pleased with frost. And it refuses to entertain the thought of deep freezing.

Store it in a frost free but cool room over the winter.

Outdoors, mulch with the old leaves and straw. Remove these first thing in the spring after all danger of frost has passed.

pond landscape

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