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.
| Botanical name | Ammophila arenaria |
|---|---|
| Common name | Marram grass |
| Family | Poaceae |
| Type | Grass |
| Bearing | Upright |
| Height | 1½ 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 late spring to late summer |
To 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.
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.
Marram grass asks for very little, but the few jobs it does need fall at set moments in the year. Here is the whole cycle in one place.
| Task | When | What it involves |
|---|---|---|
| Planting | Autumn | Set young plants in full sun and sandy soil so roots establish before summer |
| Cutting back | Start of spring | Shear the clump so fresh leaves are sent out — the only regular chore |
| Dividing and propagating | Autumn | Lift with a spading fork, split the clump with a sharp spade, replant elsewhere |
| Pest and disease checks | Not needed | Nothing to spray or treat; the grass is left alone by pests and diseases |
| Containing the spread | At planting time | Sink a rhizome barrier, such as a holed basin or barrel, around the roots |
Beyond these few moments, marram grass largely looks after itself.
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.
In fall, to propagate marram grass, simply:
Marram grass is a very resistant grass. It is not vulnerable to any disease, nor are any pests known to harm it.
Since 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.
