Overwintering ornamental grasses: here’s the proper way to do it

1_Strauss_VisionsPictures_13668740 — Various ornamental grasses in the garden in a summery shrub bed with yarrow and purple loosestrife.

Your ornamental grasses can overwinter outdoors as most of them are winter-hardy. However, some still need protection against the cold. Here’s how to wrap up ornamental grasses to protect them in the winter.

Winter protection for ornamental grasses

You can protect ornamental grasses from the cold in a variety of ways: tie the leaves together, wrap them with fleece or cover them with mulch. Sometimes it also makes sense to do all of these things.

However, not all ornamental grasses are the same. Therefore, you should not always proceed in the same way when overwintering the plants.

In general, you can assume that most perennial ornamental grasses bought from a nursery or garden centre are winter-hardy. This means that they can stay outside in the winter. However, some ornamental grasses are more sensitive than others where cold is concerned. You should protect these plants in the winter. Incidentally, it is not primarily the cold that could damage ornamental grasses. Rather it is the wetness and the sun in winter that are often a problem for the plants.

The method for overwintering your ornamental grasses in the garden or on the balcony depends on the species, whether they are deciduous or wintergreen and the location of the plants. You can build a cool tipi to protect your roses against snowdrifts and frost.

2_FloraPress_Evi-Pelzer_01905879 — Hoarfrost on fountain grass (Pennisetum 'Hameln'), Chinese reed (Miscanthus), Rudbeckia, Korean feather reed grass (Calamgrostis brachytricha), and panicled hydrangea (Hydrangea paniculata).

Here’s how to overwinter ornamental grasses in a bed

As soon as the autumn starts to turn colder, you will start to notice wrapped up or tied up ornamental grasses in many gardens and on some balconies. Because this is the time lots of people protect their gardens from the winter. Generally it is correct to protect various plants from the winter. However, with ornamental grasses it is not always sensible, as excessive winter protection can even be harmful for some species.

Ornamental grasses are happier in drier soils. Very wet autumns and winters are not ideal for the plants. If they are then also wrapped in fleece or if the soil is covered in foliage, wetness can gather underneath. This can lead to the plants beginning to rot.

Blue fescue, for example, should not be wrapped up in the winter. Golden oats and blue oat grass do not tolerate winter protection well.

On the other hand, winter protection is important for the wintergreen pampas grass. It also makes sense to protect giant reed against the cold. Tie the leaves of these grasses loosely together in the autumn. Wrap fleece around them and fill the spaces in between with foliage. This protects the plant really effectively against low temperatures. If some leaves stick out a lot and make tying or wrapping the plant difficult, cut these off with sharp garden shears, such as the EasyPrune from Bosch.

Do not use film to wrap the plants. It is not breathable meaning moisture can seep in and the plants will also not receive enough fresh air.

The majority of deciduous ornamental grasses such as Chinese silver grass, foxtail fountain grass and switchgrass do not require any winter protection. These plants tolerate the autumn and winter temperatures well. However, this only applies if these grasses are only pruned back in the spring, shortly before new shoots start to grow. This can be down powerfully and safely with the cordless KEO garden saw from Bosch. The dry stalks of these plants ensure completely natural protection in the autumn and winter. They shield the heart of the plant well and keep out winter wetness. These grasses look particularly attractive in the garden or on the balcony in a hoarfrost or snow.

You can find out about other things you can do in the house and garden to arm yourself for the winter here.

3_FloraPress_Visions_00836999 — The leaf crowns of wintergreen ornamental grasses, such as the pampas grass here, are bound together in the fall. This protects against cold and damage from breaking.

Here’s how to protect wintergreen ornamental grasses from the sun

All the above ground plant parts of deciduous ornamental grasses die off in the autumn. You can leave these standing and only prune them back in the spring using grass and shrub shears, for example. So they do not need any winter protection. It is a different story for wintergreen and evergreen grasses: various sedges or woodrushes continue to show their attractive leaves during the cold time of year. Protect them in the winter so they are not damaged by the cold and wet.

The majority of wintergreen species do well in the shade. But the plants have a more sensitive reaction to the sun. In the autumn, when the trees in the garden drop their leaves, the sun shines directly on them. If you do not protect them during this time, they may suffer sunburn in mid-autumn or winter.

Protect woodrushes from cold in the garden with a thick layer of foliage. You can cover evergreen sedges with brushwood. If you live in an area with large amounts of snow, this will serve as sufficient sun protection for the plants.

If you want further color accents in your garden along with the wintergreen ornamental grasses, we have 6 ideas for you for evergreen plants that even flower in the winter.

4_FloraPress_Daniela-Kunze_01340496 — Decorative grasses bound together and capped in snow standing in a row in the garden. Chinese reed, fountain grass, and switch grass, on the other hand, survive the winter without any protection, provided you don’t prune them back in the fall, but wait until the spring.

Overwintering ornamental grasses in pots

If some of your ornamental grasses are in pots, these will need a bit more winter protection than plants in the bed. There is less soil available to grasses in pots. If they freeze through in very low temperatures, ornamental grasses such as needle grass or oriental fountain grass will sustain damage.

You should also provide good winter protection for grass species in pots which do not require any protective measures in beds. Chinese silver grass and woodrush, for example, need warm protection if they are cultivated in pots or containers.

So you should wrap pots and containers with fleece or coconut matting before the first frost. You can also use bubble wrap. This is a particularly good insulator. Wrap some hessian around this to make it look more attractive.

Add some foliage to the soil in pots. This also protects the roots of the grasses against cold and helps them when overwintering. If you have several ornamental grasses in pots, draw these close to one another. This will help the plants retain warmth in the group and they will not cool so quickly.

You can place smaller pots together in a bubble wrap covered box to overwinter. Then fill this with straw or foliage.

The perfect place to overwinter your grasses in pots is a north-facing wall. The plants will not be exposed to any sunlight there.

To protect the plants against cold from below, place them on clay feet, a styrofoam sheet or a thick wooden board. All three solutions will stop the rising cold from underneath. Clay feet have the advantage of allowing rainwater to drain particularly well through the drainage hole in the bottom. This prevents waterlogging in the grass pots. Otherwise, they could freeze in pots at sub-zero temperatures.

If you want to know more about when you should do what kind of work in the garden, you can find out the best times for all the important tasks in our Gardening Calendar. If you build a spring bed in the winter, you can start sowing lettuce, radishes, carrots, and spinach as early as February.