A couple of depressing truths about evergreens

Have you ever thought about how very few smallish evergreen shrubs there are with any longevity to speak of?  If not, don’t.   It might be best not to read on.  It’s too sobering.

Indeed, evergreen shrubs in general are pretty poor at longevity.  The best of them are rhododendrons, camellias, some of the laurels and some of the viburnums.  These can easily outlast you.  But they’re all large, if not huge.

I’ve been lead to this depressing reality by a recent obsession with Nicole de Vesian, thanks to Louisa Jone’s latest book (Modern Design in Provence, Actes Sud 2012), along with a need to think about plants that are capable of providing an evergreen matrix in which to plant lowish perennials, in prep for an upcoming workshop.

Marylyn Abbot’s clipped santolinas at West Green. How long do we give ‘em?

What I’m after are smallish shrubs, by which I mean in the 800 to 1200mm range.  Most are short-lived.  Think of lavender, cistus, rosemary and all that Mediterranean stuff.  You’ll get five good years, and you may, at a pinch, in poor soils and with routine clipping, get 10.  But no more.   They’ll last this long, alright, but you’ll begin to wish they didn’t, as they become increasingly leggy, patchy and hollow.

I love these dwarf acacias, like ‘Limelight’ (front right) and ‘Curvaceous’, but have you ever seen them looking any good past 7 or 8 years? There’s probably more good years to be had out of the clipped Westringia on the left, but even they’re better replaced pretty frequently

There’s stuff like Pittosporum ‘Golfball’, but my experience with ‘dwarf’ or small forms of pittosporum is that they’re not so much small as slow.  It feels like they take too long to get to a useful size, and next time you look they’re too big.  I planted some ‘Silver Sheen’ with the intent of clipping them into balls.  They were brilliant for four or five years, but after seven, they’re obese, and they’re totally intolerant of any serious slimming regime.  They don’t recover from clipping back into leafless branches.

Box. Can you beat it?

To be honest, about the only totally reliably long-lived evergreen I could come up with in this size range for my climate is box, either English (Buxus sempervirens), or Dutch (B. sempervirens ‘suffruticosa’), and these are going to need clipping for them to look their best, and to remain in this size range (or at least that goes for English box, which will eventually become a small, open structured tree if left unclipped).

Fortunately box is the evergreen shrub par excellence, being phenomenally long-lived, tolerant of being cut back to virtual stumps or skeleton if necessary, and unconcerned about being shaded or draped over by other planting for a season or so.  Box is also very drought tolerant once established, though it does have a tipping point beyond which it simply will not recover, as those who’ve grown it in pots will attest.  A single very hot, dry day can take it past this point, though you won’t know that it has tipped over the edge for several weeks, after which you’ll notice it start to lose it’s sheen and to assume a slight bronzy tint.  It’ll be months before it actually looks entirely dead, though there’s no avoiding that outcome.  Plants in the ground very rarely reach this point.

Very old box at Tintinhull. They’ve been hacked back to skeletons at least once – possibly several times. Recovery is slow, but reliable

The only other smallish evergreen shrub that I could think of as having a several decade ‘best before’ date is Choisya ternata. This can get bigger than our agreed range – easily to 1.5 or 1.8m, but can be reasonably easily size-controlled, either with shears or secateurs.

Choisya – smack in the middle, forming a nice, long-lived dome – in this case without clipping. The aggies in the front don’t do a bad job of that either, and unlike so many other strap-leaved plants, require virtually no foliage grooming. But more on strap-leaved stuff later.

There’s the straight species which everyone knows and takes for granted, or the fine-leafed form named ‘Aztec Pearl’, which is going from hard to find to harder to find.  I notice that one of the big wholesalers has released a new one with fine leaves called ‘White Dazzler’.  To be honest I can’t imagine being dazzled by a Choisya, and I’m not sure I want to be – it’s not what I grow them for – but I’ve yet to lay eyes on it, so should withhold judgement.

Along with the longevity thing, the other issue that raises its head when thinking of shrubs in a carefully height-controlled environment is the fact that shrubs actually don’t have an eventual size.  Despite what the labels say, they don’t simply stop growing once they’ve reached some textbook dimension.  They’re either growing or they’re dead.

Beschorneria (the strap-leafed thing) – the exact same height they were a decade ago. No evergreen shrub can manage that

No wonder, then, so many gardeners find the strap-leafed things so useful.  Dietes, Lomandra, Phormiums etc continually renew themselves from the base, so are capable of maintaining a fixed (and reasonably predictable) height.  Not that they’re entirely interchangeable with shrubs, but they offer an almost irresistible solution where you want a dome of evergreen foliage of fixed dimensions. Many, of course, share the ‘best before’ date issues of shrubs.  I mean, is there anything more depressing than a six year old Lomandra?  full of dead foliage and impossible to effectively groom.

 

 

(about 18 hours after posting this, it occurred to me that there are clear exceptions to the no-eventual-size rule of shrubs, being those that produce cane-like growth from the base (think hydrangeas, Philadelphus, Forsythia etc).  But as it happens, nearly all of these are deciduous shrubs, and nearly all evergreens grow from peripheral growth so that they inevitably accumulate bulk, however incrementally.  But more on this in some later post..)

 

 

 

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31 thoughts on “A couple of depressing truths about evergreens

  1. Rhaphiolepis ‘oriental pearl’ or ‘spring pearl’ and Pittosporum tobira ‘miss muffett’ are great for that naturally mounding evergreen shrub with both taking the shade well.
    They won’t clip up like your buxus due to their larger foliage but they are great value for money to get that mounding form in a garden without the ongoing huge maintenance.

  2. what about teucrium fruticans ? any one had luck with it? I see it around a lot and prunes well, not sure about its longevity though….?

    • Yeah, it prunes really well. It just grows way too quickly, and in long, unbranching stems that quickly ruin the outline you’ve trimmed. Like you, I have doubts about it’s longevity (though curiously, regular clipping seems to extend this). Having said all that, I’d happily use it to provide clipped-shapes quickly, even if I had slower growing stuff nearby to eventually take over. I’ve also been longing to try that really upright form that PGA has recently released.

  3. I also enjoy westringias for low domes
    Viburnum tins surprisingly makes a great low hedge and regenerates
    From the base .

  4. I’ve been trying over the last few years to create a heat/drought tolerant garden in Sydney. I like the idea of mixing perennials like Naffray pennisetum and Salvias with a more permanent structure of small evergreen shrubs. Thus far my Raphiolepis Oriental Pearls are looking great, dense even without clipping (but sadly only flowering once even though they say repeat flowering).
    I’m thinking of adding some of the smaller Westringias, either Grey Box or Aussie Box and wondered if you have any experience of them? I do worry about their longevity because I want about 40 and the cost….
    One plant that’s done really well for me thus far is Cousin It Casuarina which is thriving in a hot dry spot making a very attractive ground cover at the front of the garden. Also good spilling out of urns or pots apparently.
    Isn’t Pyracantha a weed because of the berries?

    • Hi Wendy. I’d worry about the longevity of Westringia also. It proved itself remarkably intolerant of drought here in Melbourne during our latest dry period (period? what am I saying? it was nearly a decade, and diabolically dry). Having said that, I’d always plant them from tubes which very substantially reduces the cost (and, in my experience, the rate of natural attrition).
      As for the Pyracantha, my understanding is that it has been unavailable in the trade for years due to the weed potential, so I’m guessing that some progress must have been made with this clone (possibly sterile?) for it to be marketable.

  5. Michael’s commentators are so knowledgeable they send me scuttling to Google to see if I can find a visual to match all that horticultural Latin. I feel I’m getting a proxy education by social media (and an international one at that!) . So how clever did I feel to know what the garden that inspired the post – Nicole de Vesian’s la Louve – looks like. That was only because a few weeks ago I edited a blog post by Peter Whitehead on the garden and oggled the pix saying Wow wow a lot. I may be the only one of Michael’s readers yet to discover this garden, but if not, you can read Peter’s post here – http://blog.rosstours.com/europe/la-louve-a-garden-in-provence/

    • Nice link, Robin. I love that garden so, so much. What is it about it? There’s so many garden pics that make me want to go see a garden. Pics of La Louve make me want to live in it…

  6. When I first read your post I thought that there would have to be heaps of good small evergreens, but then I started to list them in my mind, and it was much harder than I thought. The box are the best and there are some great alternatives to sempervirens like B. recurvata Bodinerii, Curly Whirly, and Kingsville. Add Rhapiolepis Snow Maiden to Oriental Pearl and what about Phillyrea, Eleagnus rotundifolia and pungens which clips perectly and Ilex cornuta Rotundifolia?
    In the shade there’s Daphne, Sarcococca, Pieris, Skimmia
    Catherine’s Carissa, Murraya Min a Min, jasmines and Gardenias if we’re not plant snobs and live somewhere warm. Posoqueria is sensational.
    I use a great dwarf Westringia called Milky Way, there’s Acmena Tiny Trev, Baeckea virgata Dwarf form, Banksia spinulosa and Birthday Candles.
    berried shrubs like Cotoneaster Donards Gem and Pyracantha Ruby Mound.
    Nicole’s Mediterranean plants like rosemary are unbeatable and although short lived, they grow fast. Lambleys R. Mozart looks good and I love Blue Lagoon.
    If Nicole had of seen Cookia virgata Silver Cloud then that would have been her favourite grey leafed evergreen, as it is mine.
    I’m out to clip some box when it’s not so cold…

    • It doesn’t help when I start out writing about longevity in smallish evergreens, and somehow morph into writing about clip-ability.

      A bit like my Dad who was playing a piano solo at a concert while very crook. When he started he was playing Mozart. By the end he realised he was playing Beethoven – and could never recall the point of transition.

      Thanks for the extensive warm-temperate/sub-trop list, Michael. I call that heaps – particularly given my very lame choice of two.

      Wish I could do the Posoqueria (which I had to look up, commenter Robin!).

      The pyracantha is something I could – and can’t wait to – do.

  7. Golden diosma.

    Not for snobs though. I’ve seen it used to great effect once or twice, but I …..just….. can’t…… do…… it….

    • I know. I’m exactly the same. I keep trying to tell myself that I’m too horticulturally mature to be so dismissive – that the plant has all sorts of merit, particularly (so the self-talk goes), the straight green one. But then, like you, I just can’t do it.

  8. I’ve been enjoying your blog/site for awhile now…finally braving a comment. I garden on southern Vancouver Island, BC, Canada. Without getting into (slow) dwarf conifers…but think Cryptomeria forms…
    I have been enjoying the blue-ish green leaves of dwarf Rhododendron “Ramapo” and have started taking shears to Japanese azaleas that can almost look like box except for their Spring volcanic colour episode. Here we have been seeing an increasing variety of NZ Hebes, species and cultivars – I still will resort to H. buxifolia, or H. rakiensis for “evergreenery”. Genista hispanica can take some pretty hard shaping/pruning immediately after it blooms and then makes a nice grey green shape that looks soft..until you touch it! Just a few random evergreen thoughts from a new fan across the Pacific. Cheers all.

    • So glad you’ve braved it Cyril. Someone else mentioned that they were too scared to comment, which I thought was hilarious. I mean, we’re all just on this journey together. But then I was commenting on GardenDrum this morning and got all freaked out. I wrote a reply, deleted it, wrote it again, made several repairs etc etc. I had to give myself a good talking to, then force myself to press ‘Enter’.
      Conifers, of course, are a whole new ballgame. Not that we have many that would stay within the height restrictions. Cryptomeria is only any good in the coldest of our climates. But given that, and your cold, I can’t believe you can do the Hebes where you are. They’re all super short-lived for us, or at least have a short ‘best before’ phase. Dwarf rhodos and azaleas are firmly plants of the shade here, but certainly break the short-stature/short-lived thumb-rule. Doesn’t the tight clipping of the azaleas interrupt their flowering, or can you get away with that if its carefully timed?

      • gosh…its interactive!!! this neophyte’s reaction to social media! Hi Michael and thanks for encouragement.

        as for the azaleas – Hino Crimson with its smaller leaves works well – I clip them not too long after they have started making new growth, and then there is time enough for them to adjust, grow out a little and set buds for Spring. One group I’ve been working on now for over 20 years, bloom regularly..their only problem is getting totally swamped by Tropaeolum speciossum of which I remove excess growth by the wheelbarrow full – and now I read this creeper is on the invasive plant list in NZ.

  9. Here in southern inland Queensland I am also looking for hedges and edges. Jap Box is my standby but I have a really tough euonymus hedge that is only 50 cm high. It was labled “euonymus m” it is about 5 years old so we will see how it goes. It is slower than the box. I also have verigated euonymus clipped into balls in amoungst the perennials. It has a bigger leaf than the “m”.
    My other standby is the eleagnus ebiganii (spelling?). I keep it clipped at 1.2m but again it is only about 7 years old so we will see.
    The others that I am having success with are darwf abelia, including the dwarf golden one and a smallish conifer called morganii. Again only in for 7 years so time will tell.

    • You’re right. Those dwarf/smaller euonymus are excellent, but they take ‘slow-growing’ to a whole new level. They relish it. They wallow in it. Come to think of it, slow growth seems to be the key with plant longevity.
      We love E. x ebbingii around here, but it’s usually used as a hedge to about 2m. Of course, that doesn’t stop it being restricted in my height range. To be honest, I became aware about half-way through writing that post that if I was prepared to clip, then the natural height of whatever shrub was under discussion was irrelevant, and kind-of nullified my argument. But I soldiered on nevertheless, consoling myself that my central argument still stands – that naturally smallish shrubs are alarmingly short-lived. As long as you’ve a pair of shears to your name, there’s still plenty of options.

  10. Yes, I suppose you are right, yet I rail against buxus on perverse principle, especially English box with its appalling tom-cat smell. For a warmer climate like Sydney, I can recommend Murraya ‘Min-a-Min’, Abelia ‘Snow Showers’, Raphiolepis umbellata (very hard to find as newer Raph cvs have taken over the market), Carissa ‘Emerald Star’ and Acmena ‘Allyn Magic’ for small, structural stayers under 1m high. My Min-a-Min is now over 10 years old and is such a perfect dumpling mound, I feel compelled to pat it whenever I walk past.

    • Thanks for the warm-temperate list, Catherine. Looks like you might have more to choose from (again!). The abelia might even work for us, and is one of those very rare evergreen cane-growers that I mention in the addendum just added to this post.
      I won’t argue with your perverse principle. Many a good garden has been constructed on principles more perverse and prejudiced than that.

  11. I have so often lamented this fact Michael! When I use these shrubs in a clients garden I am often left carrying a conscience knowing that we will have to address replanting in 5 or so years. There is no such worry when gardening on Mt Macedon for as you say Camellia, Rhodies, especially the airie faeries, etc all live well beyond a decade.
    At least they used to ! Over the last decade many of these persistents have perished with drought and extreme fluctuations of climate, wet and dry.
    Most of these smallish shrubs are, as you suggest Mediterranean. We also have a choice of a number of Australian natives; Correa, Westringia, some Callistemon, and many others. Again all are short lived and all have the propensity to annoyingly outgrow themselves in a most unbecoming way before their demise.
    It occurred to me that nearly all these shrubs come from hot, dryish, impoverished regions, which I suggest genetically challenges their longevity.Though Choisya comes from SW America and Mexico, Camellia’s, Rhodies , Viburnums etc more usually come from China or the Himal. I suspect that SthAmerica has a wealth of plant material we have not yet explored . Let alone somewhere like Ethiopia; and the rest of the world. It is not all desert.
    Maybe,simply, as in the animal world, larger species are generally longer lived!

    • Hey yeah! Big animals – long life. Hadn’t thought of that. Obviously there’s some biggish plants that are short lived, and some small ones that last a very long time, but there’s definitely a trend there..
      As for the impoverished thing challenging longevity, it seems more like finding themselves in rich, fat garden conditions is what shortens their lives. In their natural conditions, they can last a very long time. It’s a bit like us, really – in too rich conditions, we grow bigger faster, and our lifespan drops accordingly

  12. Michael- I just love your ideas and the way you express them.
    Agree with everything you say here but Choisya? Really? I can’t bring myself to plant it much less smell the plant when pruning.
    Buxus is most certainly a winner and Buxus ‘Suffruiticosa’ is self mounding (and slower growing) so arguably requires less pruning.
    I love dwarf Rhaphioleips ‘Oriental Pearl’ – when planted en masse the foliage is superb.
    Keep the pots coming…

    • Yep, Choisya. You don’t like? I think it was gardening in England for a while that made me see a whole lot of previously taken-for-granted stuff with new eyes. I can’t pass a bog-standard Acacia baileyana in full bloom now without thinking “What they wouldn’t do to be able to achieve that…”
      Gotta get me some of that Rhaphiolepis. It was another thing that I used to just sneer at back when I was first gardening in the ’80′s, but have often looked at again, head tipping right and left like my kelpie when I try to have serious conversations with her, thinking ‘you know, that’s a damn-fine thing’. And of course, it’d be so Nicole d V!

      • Isn’t Rhaphiolepis a nice medium size shub with blue-black berries that self seeds like there’s no tomorrow? I keep pulling out dozens of these seedlings from my garden almost each time I do any weeding, because my neighborus grow a couple of them. Euonymus japonicus aureo marginatus would be my top favourite evergeen (ever-yellow?) shrub, and it’s not really that slow to grow. Tough in any conditions, any aspect, any soil, and ever so cheerful! And I have never seen any of it’s pretty seeds germinate anywhere! :-)

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