I feel sufficiently confident to give an interim report on the grasses I have used in the new Court Garden although it will take another few years before I can give a definitive verdict. These are bigger growing grasses because we had the space and I wanted an immersive effect that wraps around when we walk through the area.
The site is the hottest area in our garden but, being lowered, it can also be frosty in winter. Cold air flows down to lower levels to settle. The ground is typical free-draining, Taranaki volcanic soils that do not become water-logged and never dry out entirely. We haven’t added any fertiliser and once planted, we never water. The area is mulched with wood chip.
Chionochloa rubra – NZ native so evergreen. It takes first prize for graceful form because it fountains out from a narrow base and that form makes it a real star in the winter garden. Its flowering is relatively insignificant but I don’t have to groom the plants to remove dead sections. We started with just one plant and I kept dividing it, which it does easily. I have never lost a plant. It needs space to be able to appreciate the graceful form and the best plants are now 120cm high with a spread up to 2 metres.
Chionochloa flavicans – also a native, sometimes referred to as ‘miniature toetoe’, so evergreen. At its best in spring but holds its showy flowers right through until autumn. Rabbit fodder when young. Has the reputation of ‘whiffing off’ unpredictably and it certainly doesn’t appreciate being crowded by other plants. Again, we started with a single plant and kept dividing. I have overplanted it so will lift the lot shortly and split the plants, replanting fewer and at wider spacings. I am hoping that by dividing, it will stimulate more growth and delay any inclination to ‘whiff off’. Plants are now about 75cm high and up to 140cm wide.
Anemanthele lessoniana – another native – so evergreen – with a vase shaped habit of growth and more colour variation in the foliage. Lovely in bloom with a cloud of fine flower heads. I had this in the twin borders but the plants were getting too large so I have now moved them to the Court Garden. When stressed (and my plants have often been stressed as I have lifted and divided them to increase the number from the original three), it turns an attractive gold but I will need to groom the foliage to remove dead thatch when the plants make fresh growth. It has reached about 90cm high and up to 140cm wide.
Austroderia fulvida – toetoe so another evergreen native. Very large growing and too early for me to comment on its longer term performance. I bought three small plants through Trade Me and they have already reached 1.7m high and 2.4 metres wide.
Stipa gigantea I have referenced countless times. It, too, is evergreen in our conditions and I give it the occasional groom (by hand or with a leaf rake) to remove dead foliage. Excluding the tall flower spikes, it is about 80cm high and 160 cm wide as it matures. It divides and increases easily so just start with a single plant but you do need a certain critical mass to have sufficient to share with the sparrows. We found the pesky birds stripped the blooms in the first season and the whole reason for growing this grass is for its showy, long-lived flower spikes so that was disappointing. This year we have had plenty to share with the birds. The foliage has a glaucous tint which is a contrast.
Calamagrostis ‘Karl Foerster‘ – I have written about this before. It is such a strong grower, spreading at an alarming speed, that I reduced it down to just six plants which I am hoping I can keep in check by root pruning on an annual basis. By root pruning, I mean getting a very sharp spade and cutting back the size of the clump without digging it all out. That way, I can get the spreading fresh growth off it. This works because it makes its new growths on the outside of the clump. It is evergreen in our climate but the foliage looks pretty scruffy by the end of season. I am pretty sure I cut it back hard last winter so the spring growth was all fresh and lush. It is one of the first grasses to flower in spring and those lovely plumes hold all summer and into autumn. It is all about the plumes because the foliage and form are nothing remarkable.
Calamagrostis ‘Overdam‘. At least, I think it is Overdam. It was given to me. It is strong growing too, but not as threatening as Karl. It has the same lovely plumes but the bonus of clean, variegated foliage which stays looking fresh through the season, somewhat like a lower growing variegated miscanthus, though it spreads sideways rather than up. It will likely need root pruning, too.
Miscanthus sinensis ‘Morning Light’. Look, we started with one plant in the garden years ago that just sat, grew annually and fell apart because it needed dividing. As soon as I started dividing it (done variously with a sharp spade, an old handsaw or a small axe), it responded by growing with huge enthusiasm. I overplanted badly and need to take out at least half of the plants but as it is all about the plumes in late autumn and early winter when they glow white in the low sun angles, I will wait. The plants are around 1.7 to 1.8 metres high with flower spikes on top of that so it is very tall. If it is divided often enough, it will stay together – falling apart from the middle is a sign it needs dividing. It is fully deciduous, fine leaved and variegated. Mark is sure that the old foliage has potential for thatching but he has yet to test this theory. This is the only grass that I have spotted seeding down so far but the seedlings are easy to pull out when small.
Miscanthus whatever whatever – may be just a larger growing form of sinensis with a wider leaf but it should be called Miscanthus giganteus variegatus. The leaves are wider and with a most attractive, clean variegation but the vigour and size is daunting. We ended up digging out three massive plants because I couldn’t hold them together and, as they fell apart, they blocked the path entirely. This is a triffid of a grass. Gardening friend, Susan, suggested that maybe the way forward is to do the Chelsea chop on them – cut them back to ground after the first big flush. I think she is right and I will be cutting them back to ground level about mid November. The second flush of growth should be more compact and shorter. If I can’t keep them under control this way, they will have to go. The plants are too big for me to lift alone and I don’t want to commit to plants that need lifting and dividing annually.
Lomandra We had a named variety in the garden but I found a better option to replace it with. I rate lomandra as one of the world’s more boring plants and I suggest you leave lomandras to supermarket carparks and roading roundabouts. We have more interesting and attractive native grasses without having to resort to this utility Aussie in NZ gardens.
Here endeth the interim grass report. Except to say that I am moving and dividing some now because we still have at least six to eight weeks of the growing season left before temperatures drop and growth slows or stops over winter. That said, I have done this in winter and we can get away with it but it is not recommended in less benign conditions where the plants may just sit and decompose in sodden, cold soils.