Marram beach grass, holding the sand in place

Marram grass against the sunset

Key Marram grass facts
Botanical nameAmmophila arenaria
Common name – marram grass
Family – Poaceae
Typegrass

Bearing – upright
Height – 1&1/2 to 5 feet (50 cm to 1.5 m)
Planting density – 8 to 10 plants per sq. yard (m²)
Exposure – full sun
Soil – sandy

Flowering  – from May to August

Planting marram grass

Marram beach grass is a typical seaside grass. It’s often topping sand dunes where the grass helps lock the dunes in place with their roots. This capacity to send roots far and wide in the wild is what makes marram grass such a good choice in gardens with poor soil that drains very well.

Planting distance is about a foot, more or less 30 cmTo plant marram grass, the most important factor is exposure. Since it’s used to growing in full sun along the coast, this grass particularly loves full sun and sandy soil. To make sure young plants survive, it’s best to plant them in fall. This gives the plant enough time to create a root system that’s strong enough to cope with hot summers.

Smart tip:

Marram grass is very effective to stabilize dunes thanks to its deep root system that spreads fast. In a garden, this might turn against you: it makes the plant invasive. To make sure this doesn’t happen, feel free to set up some kind of rhizome barrier when planting (a plastic basin or barrel with a hole at the bottom will do the trick). This will make controlling the plant’s spread easier.

Caring for marram grass

It won’t take you much time to care for marram grass. Indeed, all you’ve got to do is cut the clump back at the start of spring so that new leaves are sent out.

Multiplying marram grass

Caring for marram grass is easy and only involves cutting it back in winterIn fall, to propagate marram grass, simply:

  1. Dig out the plant itself with a spading fork.
  2. Divide the entire clump with a sharpened straight spade.
  3. Transplant the new plants in other areas of your garden.

Diseases and pests

Marram grass is a very resistant grass. It is not vulnerable to any disease, nor are any pests known to harm it.

Landscaping uses and companion plants

Landscaping with marram grassSince that’s where it evolved, marram grass could not be better suited to coastal gardens and stabilizing embankments.

It will also grow very well in flower beds, together with other grasses such as Miscanthus, Pennisetum, Stipa tenuifolia, Imperata cylindrica and also blue fescue, for which the blue-gray blades of grass pair well with the golden green of marram grass.

Perennials are also great together with this plant. They’ll add in a range of shapes and colors that will contrast with this grass’s wind-swept clumps. For instance, several options to chose from are Polygonum, Aster, hemerocallis, asphodel, iris, etc.


Image credits (edits Gaspard Lorthiois):
Pixabay: IngV, Krimhild Kersting, Rob van der Meijden, Emmy Hufner