Tag Archives: Acanthus mollis

Cover the ground

Happy and easy care perennial impatiens

Happy and easy care perennial impatiens

I mentioned last week about my mother’s gardening mantra being ground cover which focussed my mind on the case for ground cover plants. Surprisingly, this preoccupation is a relatively recent phenomenon.

Back in the 1950s and 1960s ground cover plants hardly featured. It was all about trees and shrubs with little under planting. Now it is often regarded as a hallmark of good gardening to have no dirt showing at all – except in the vegetable garden. Mostly it is about packing the garden with layers of plants, each lower layer masking the stems and trunks of the taller ones while down the bottom is some low but strong growing ground hugger.

There is good sense to not having exposed dirt in a garden. Keeping it covered stops dirt splash in the rain, wind blown top soil in the wind and erosion in torrential downpours. A good thick layer of something, be it plant or mulch, can cut down on the germination of weed seeds lurking in the soil because it reduces the amount of sunshine and light that most need. It is also a great deal more attractive than the liverwort that colonises uncultivated ground in shaded areas.

There are ground covers and there are G-R-O-U-N-D C-O-V-E-R-S. Some modest little ones never get ideas above their station and just gently colonise an area, spreading in a quiet and acceptable manner. In this class, I would put the unassuming but pretty little scuttelaria which we have in both white and blue or the obliging corylopis and a number of the ajugas.

Then there are the rampant ones which, given even a hint of an invitation, will spread at an alarming rate. I once bought a punnet of such a plant which looked promising. I have long since lost its name but it had pretty white cup flowers and good green, fine foliage. That punnet held six plugs, each measuring about 2.5cm across. Within one season, each of those plugs measured a metre across. I have never seen anything spread so alarmingly. It took me two years to get rid of it entirely, all the time muttering that the people who propagated that plant for sale should be lined up and shot. For the same reason, I have eradicated the Orangeberry plant (Rubus pentalobus) and rampant violets. I don’t want lemon balm either. It stages a takeover bid, choking everything in its way. And the ornamental tradescantia is pushing its luck.

Zephyr beside the Acanthus mollis

Zephyr beside the Acanthus mollis

We are extremely cautious about the triffids too. These are the large growing perennials which spread and choke out much in their path, seeding their way through the garden. Acanthus mollis or bears’ breeches springs to mind as a good example. One can be striking but don’t turn your back on it and allow for the fact that every one needs at least a metre and a half of space. Too many and your garden looks as if it is full of cheapie plants as bulk fillers. We call it the ABG syndrome after we heard somebody’s garden described as being a case of Another Bloody Gunnera. Those particular triffids are now on the banned list in this country, as far as I know – the enormous rhubarb plants.

Endless plant lists without photos make dull reading, but I will offer up a very short list of recommended, well behaved ground cover plants which have proven their worth here and should be readily available. In shade areas, it is hard to go past hostas, farfugiums and ligularias but also the francoas (sonchifolia and ramosa- the Chilean bridal wreath flowers) and phlomis. We have a wonderful swathe of old fashioned perennial impatiens (busy lizzies) which have kept on keeping on for decades in frost free woodland conditions. They flower for 10 months of the year and require next to no attention.

The mottled foliage of pulmonaria (with the unromantic common name of lungwort)

The mottled foliage of pulmonaria (with the unromantic common name of lungwort)

In sunnier conditions, the sedums work well, as do coreopsis, smaller growing campanulas, phlox, asters – there is an endless list of possibilities. I am less keen on the widely used catmint (nepeta) which I regard as too strong a grower and essentially boring. I much prefer the mottled foliage and pretty flowers of the pulmonaria which fill a similar niche.

For those who find using perennials offputting, the permanence of ground cover shrubs sometimes appeals, especially flowering shrubs. We used to sell pretty little weeping camellias (Sweet Emily Kate and Quintessence) which, if not trained upright, would become ground cover. And somebody has apparently released a “ground cover” michelia. I know this because I have been asked for it but have not seen it yet.

But, ground cover shrubs in a mixed planting? I don’t recommend them. We tried Sweet Emily Kate and very soon discovered the drawbacks. There is nowhere for the spent flowers to drop to so all that happens is that slushy blooms and other garden debris sits on top of the plant, needing frequent picking over by hand.

If you want ground cover, keep to perennials or seasonal bulbs and annuals is my advice. If you want to reduce maintenance, mulch with something anonymous like compost or bark chip instead and bypass the ground cover altogether.

First published in the Waikato Times and reprinted here with their permission.

Repetition – unifying a garden or downright dull?

A surfeit of renga renga lilies repeated throughout your garden is highly unlikely to unify it

A surfeit of renga renga lilies repeated throughout your garden is highly unlikely to unify it

How often have you heard the advice to repeat the same plant in your garden to achieve continuity? It has almost achieved truism status though I would argue that this is one piece of so-called garden wisdom that too few people ever question. In fact I would go so far as to suggest that you are better to cast that piece of clichéd advice out to the wilderness and ignore it.

I don’t know where it originated, though I would hazard a guess it was from within the landscape sector. Now it is just repeated mindlessly as a golden rule.

The first time I was aware of a plant being repeated through a garden was with Dahlia Bonne Esperance. It is a baby dahlia with pink daisy flowers and increases readily (lights should be flashing here for you, dear Reader) and it featured throughout this person’s garden. Far from giving continuity, in fact it looked like a cheap, gaudy dot plant (as in dotted around everywhere). Therein lies the problem. When the advice is dispensed so glibly that you should repeat a plant to give continuity, there never seems to be any corresponding advice as to what types of plant are most effective. And in the absence of such advice, too many gardeners fall upon an option that is cheap to start with and easy to increase.

Acanthus mollis or bears' breeches - too close to weed status to be a desirable repeat planting

Acanthus mollis or bears’ breeches – too close to weed status to be a desirable repeat planting

I am sorry to say that many plantings of renga renga lilies are not going to enhance and unify your garden. The same goes for mondo grass, liriope, catmint (nepeta), the dreaded aluminium plant (lamium), common hostas which bulk up readily, Acanthus mollis, or Ligularia ‘Britt-Marie Crawford’. They are just going to look boring and repetitive when used again and again throughout.

Truly, you can have too much, even of a good thing. I have seen gardens which suffer from the ABC syndrome (another bloody clivia), or the oh no, TMBBH trait (too many big blue hostas). You need a deft hand and very good eye to make it work well.

There may be a difference between large and small gardens here. It is a long time since I have had a small garden but I can see that restricting the plant palette and using a repeating motif could help mitigate the bitsy effect so many gardens suffer from. But if you are determined to repeat a plant, try and make it a choice one. Trilliums are good. Paris, too. Though there is a possibility that the originator of the recommendation was thinking more in terms of pencil cypress or topiary yew – a woody plant rather than a perennial. I am fairly sure he or she was not thinking of Dahlia Bonne Esperance or renga rengas.

In a large garden, hmmm. As far as I am concerned, a large garden succeeds better when it has distinct changes of mood and style. To repeat a plant or plants throughout renders it too much the same and that is when large gardens become rambling, indistinct, and not very memorable. Unless you want to be remembered as, “Oh, that was the garden with all the orange clivias/acanthus mollis/buxus hedging/catmint/day lilies.” (Strike out those which do not apply.) We prefer to aim for different groups of plants in different areas, rather than mixing and matching throughout or streaming one particular plant through the lot.

That said, there are exceptions. We are steadily drifting English snowdrops throughout (on the grounds that you can’t have too many fleeting seasonal wonders and they are satisfyingly compatible with most situations – and transient, not year round). Mark has observed before that it is rhododendrons that form a backbone of continuity to our garden. But it is not just the one rhododendron that we have repeated. While we favour the nuttalliis (the rhodo equivalent of trilliums, one could say), we have multiple different varieties used in different combinations throughout. I don’t think that is what is meant by repeating a plant for continuity.

If I have failed to convince you that the interest in a garden lies in different plant combinations, interesting plants and variety, then I would at least make a plea for considering seedling variation. Mark and I looked at a planting in a garden – a hillside of red rhododendrons all the same. They will be showy in flower and look unified in conformity when not in bloom. They are also, to our eyes, dull, utility and public sector amenity planting (and it was a public garden too). What sets a private garden apart is the opportunity and scope to detail such a planting. Had it been done in seedling raised rhododendrons (collected from the same parent plant), there would have been the overall unity but subtle variation to add interest. The same goes for a range of plants – from pohutukawa to hostas. Raising them from seed takes time but gives interest and detail which is lacking when you order in a mass of one plant only.

But then we never have been fans of mass planting and massed display. The devil may be in the detail but so is the gardening interest.

If you are determined to unify through repeat planting, at least pick something with bragging rights - desirable dark red trilliums, perhaps

If you are determined to unify through repeat planting, at least pick something with bragging rights – desirable dark red trilliums, perhaps

First published in the Waikato Times and reproduced here with their permission.