Wednesday, May 29, 2024

Things are getting out of hand - pruning required!

Can plants be too exuberant?  It isn't just the bulbs, annuals and perennials that reacted gleefully to our heavier-than-usual rainy season this year.  Numerous shrubs responded with their own effusive flushes of growth.  In many cases, a little pruning will put things right but there are quite a few shrubs that have exceeded their expected size, if also some cases in which I crammed them into spots smaller than recommended based on projections of their dimensions at maturity.  I can't claim to be especially good in the area of spatial relations.

I have a lot of  'Cousin Itt' Acacias, most of which have remained within bounds with some judicious pruning but a few have been more difficult. 

The 3 Acacia cognata 'Cousin Itts' planted under the peppermint willow in the back garden get along fine with an annual haircut
On the other hand, the Acacias in the front garden have been more difficult to manage.  When this photo was taken earlier in the month, I was barely able to squeeze through the plants on either side of the flagstone path, which is barely visible here.

I got tired of brushing through the plants, especially when they were damp so I trimmed them back this week and gave the clover growing between the flagstones a serious haircut as well.  The twiggy undergrowth of the Acacias need more work but that can wait a while.

The Callistemon 'Cane's Hybrid' I planted in 2015 has grown larger than I expected.  Its height isn't so much the issue as its girth.

When I bought 'Cane's Hybrid' in a one-gallon pot, the label claimed it'd grow up to 10 feet tall by 15 feet wide.  It's taller than that now and I've since read that it can get up to 20 feet tall.  Since it replaced a peppermint willow a neighbor (now long gone) complained interfered with her view, its height isn't a big issue; however, the back branches are problematic as they hang over the dirt path between the shrub and the hedge, making movement along the path more difficult for the gardeners, as well as me.

In the next case, the size of Centaurea 'Silver Feather' appears to have been grossly underestimated.  Having planted it in my back garden before, I knew it grew larger than its projected size (12-18 inches tall and 18-24 inches wide) yet I still underestimated its space requirements when I planted two of them in my front garden.

Last year, I was looking for a third 'Silver Feather'.  I'm glad I didn't find one!  I measured the one on the left at almost 2 feet tall and 4 feet wide.  The flower stalks are taller still and they flop over rather than remaining upright, which is the real problem.  I've tried using stakes to keep the stalks upright but they're not really aren't doing the job.  Still, I'm loathe to cut the stalks and miss out on the flowers.

The next plant grew so slowly that it left me with false expectations about what I could squeeze into the space around it.

The Corokia x virgata 'Sunsplash' has an erratic growth pattern but I'll do my best to give it a more pleasing shape.  I may end up removing the Phormium on the left to give the Corokia more elbow room.

The next shrubs have grown a LOT taller than they were projected to get.

Leptospermum 'Copper Glow' was projected to grow 4-6 feet tall and 6-8 feet wide.  I'd estimate that my 2 shrubs are about 15 feet tall and nearly 12 feet wide.  Last year I pruned them hard and lost most of their summer flowers as a result.  I'd planned to trim them shortly after they flowered but never got to it so I'll tackle that job in late summer/early fall this year.  I'll be bringing it down to the level of the roof's peak but no lower than that.

I may have been delusional when I transplanted Leucospermum 'Sunrise' from a pot into the ground.  However, I removed four 'Gold Dust' rosemary shrubs (which themselves had greatly overgrown their projected size) to make room for the Leucospermum, leaving one in place with the notion that it could be removed later if the Leucospermum needed more room as it matured.  During its first three years in the ground, my approach seemed solid.

However, this year the Leucospermum entrenched on the succulent bed in front of it.  I didn't remember that I'd planted a small Agave ovatifolia 'Vanzie' there until I started pruning back some of the Leucospermum's foliage this week.  The shot on the left shows it prior to pruning and the view on the right shows it after a light pruning.

The Agave on the left and numerous Mangaves will need to be relocated.  I'll leave some of the smaller succulents in place.  I'll prune back the remaining 'Gold Dust' rosemary for now, reserving the option to remove that if necessary next year.

I accept no blame for the oversized Pyracantha in my front garden.  It planted itself under the strawberry tree (Arbutus 'Marina') in the front garden.  Knowing nothing about the plant, which I originally assumed was a Cotoneaster, its slow but steady growth went largely unnoticed - until it showed itself to be something of a thug.

The noID Pyracantha occupies an awkward space, spilling down one side of the moderate front slope, but its attempt to take over its little corner is becoming a problem.  I intend to do some minor pruning to reduce the tall upward shoots in the short term but I may ask my hard-core tree service to bring it further down to size in the fall.

I picked up a Salvia lanceolata (aka lanceleaf sage) in 2014 at my local botanic garden, knowing little to nothing about it.  It had a projected size of three feet tall and wide and it grew slowly.  It was snuggled in next to an Acacia cognata 'Cousin Itt' which, in time, swallowed it up.

Frankly, the Salvia looks ridiculous with stems sticking up every which way from underneath the Acacia.  I contemplated removing it last year but settled for cutting it back hard after it finished flowering.  It sprung back bigger than ever this year.

I still like the unusual flowers so I'll make a stab at taking cuttings as I've never found the plant anywhere other than my local botanic garden, which no longer propagates plants for sale.  If some of my cuttings take, I'll try pruning the plant to the ground and will remove its base if I can do so without damaging the Acacia.

With the possible exception of Salvia lanceolata, hopefully I'll be as successful at reining in the aforementioned shrubs as I've been with those shown below.

Grevillea 'Superb' was supposed to grow no bigger than 3-5 feet tall and wide.  It's exceeded the outside limits of that estimate, especially in terms of its width.  The plant blooms year-round and I routinely cut back the longest stems for inclusion in floral arrangements.  That generally does the job of keeping it within bounds.

Leucadendron salignum 'Chief' is supposed to grow 6-10 feet tall and 6-8 feet wide but it grows much larger than that in both dimensions.  I missed its usual late winter pruning after it finished "flowering" but I'll give it a haircut in early fall.  It's fresh red foliage is too pretty to cut now.

Leucadendron 'Pisa' was supposed to grow 4-8 feet tall and 4-5 feet wide but it's grown taller than expected and assumed a tree-like shape.  It's tall enough to pose a pruning challenge but I'll attempt to bring it down a peg once its colorful bracts fade this summer.  If I can't manage, I'll ask the tree service to handle it.  The key is to avoid cutting into bare wood.

I've already trimmed Leucadendron 'Safari Sunset' a bit in the back but I still need to wade into the bed to cut back the front-facing stems.  My husband gets annoyed because it blocks our view of the harbor's entrance.  It takes pruning well as long as I don't cut into bare wood.  I pruned the smaller 'Safari Sunset' in the front garden about a month ago.

Placing Leucadendron 'Wilson's Wonder' here wasn't a great move on my part.  I'd wanted to break up the view of the southern end of the front garden when the area to its left was more densely planted but, now that I've opened that area up, that plan doesn't work quite as well as I'd envisioned.

Once I sharpen my pruning tools, I'll start chipping away at the long list of subjects I've outlined here.

All material © 2012-2024 by Kris Peterson for Late to the Garden Party


  1. We've all been fooled by hight/width estimates. Especially with trees and shrubs, tags should read " ten years." When it doesn't, I say it to myself because in my experience, happy plants don't stop growing after 10 years. When a successful grouping of three feels out of control, it gets thinned out to just two and even one when. The need to keep plants down to a manageable sizeI get me stressed out.
    Maybe Centaurea 'Silver Feather' flower stocks, once flopped, can find their way to a vase? :-D
    Salvia lanceolata is indeed unruly, but the flowers are wonderful. I hope your cutting project succeeds!

    1. I'd actually intended to add a couple of stems of the Centaurea to my second IAVOM vase but forgot! I'm already thinking about removing one of those plants ;)

  2. Bring out the green bins, everything is getting a chop! I'm guilty of the same, still your garden looks lovely and is thriving. The lanceleaf sage is different, and I'm glad you're saving it for a better spot.

    1. Luckily, my husband gave me not one but 2 hand pruners for my birthday (one as a backup as he contends I never take proper care of my tools). The pruner's a good one but my right wrist is still taking a beating and I've barely gotten started!

  3. I love your initial question: Can plants be too exuberant? Yes, definitely! All too often, growers are too conservative when they estimate width and height - and in our mild-winter climate plants often get larger than elsewhere anyway. (Centaurea is an excellent example!)

    When I still had my Acacia 'Cousin Itt', I found it difficult to prune. Too much pruning exposed the woody interior, which wasn't a sight I wanted. It looks like you managed far better than I ever did.

    1. Acacia 'Cousin Itt' does need its skirts lifted but it springs back pretty quickly. That said, it's a lot of work and my plants seem to get taller with each passing year.

  4. I miss my zone 10 garden but not these overgrowth issues. So many tempting shrubs esp in the protaceae family, but my small garden could not accommodate more than a few -- at least you have the room to let them shine albeit with some pruning. I had to pull out a blooming leucospermum, and I hate to think what the grevilleas are up to now! Growing mostly herbaceous stuff in Oregon, strangely enough, has been a relief. But I think, on the whole, your having so many beautiful mature shrubs is a huge asset to work with.

    1. My other Leucospermums have been much more accommodating than 'Sunrise' but perhaps I should've known better. I think the Leucospermum in a neighbor's garden up the street is 'Sunrise' and, after 20+ years in the ground, it's huge. As I get older, I think I may need to find myself a "proper" gardener that knows how to keep shrubs like that tidy.

  5. You certainly have your work cut out for you, Kris! I find that nurseries often greatly underestimate plant stats, not sure why... maybe they sell more?? Years ago, I bought a cypress with a tag of 3' x 3'... it is now a 20' tree! Where is the truth in advertising? :D Eliza

    1. I had a very similar experience with a Duranta repens 'Gold Mound' many years ago, Eliza. When I bought my first one, it was labeled as 3x3 feet tall and wide but it reached 12 feet tall (despite annual pruning) before we took it out a year or 2 ago. In the interim, I'd purchased others which never got as big but which I ended up pulling out as well. I even addressed the issue with one of the nurseries selling the plant. Sometime later, I noticed that the newer plants of the same name were labeled 3-20 feet in height. Why would anyone buy a plant that unpredictable?!

  6. I must say Kris, I can totally relate to path obstruction. I have a hard time editing plants that billow over the right of way. My Leucadendron 'Ebony' is the latest perpetrator, and my conviction that I couldn't grow it here increases my reluctance to cut it back off the path. Maybe I should just get rid of the path !

  7. I'm glad I'm not the only gardener with spatial relationship issues! A gardeners work is never done. We work to plant and cultivate, then we work to keep what we planted within bounds. Mother Nature did a lot of hard pruning for me this last winter, my two Corokia x virgata 'Sunsplash' and multiple callistemon (as well as many other things) were killed to the ground.

    1. Mother Nature clearly isn't good at pruning, Loree :( While winter conditions are rarely an issue here, MN occasionally tries to incinerate plants during our summers. We haven't had any brutal heatwaves in the last 2 years but I'm not sure we can expect that trend to continue.

  8. Pruning is one of the most difficult jobs. Hard to find the right places to cut out that will keep a pleasing shape and not ruin everything. And, most of the things I plant end up way bigger and much faster than the tags say they will (though there are a few exceptions that grow much, much slower than I want - Pyracantha being one of them!). I've got a Leptospermum rupestre that I adore, but it has become an unwieldly mess and I have a difficult time figuring out how to prune it well. Still, it must be done.

    1. I'm chipping away at the pruning tasks but, feeling a bit of pressure to get on with setting up my summer cutting garden, I'm balancing pruning with the equally arduous task of clearing out my raised planters and preparing them for planting. In either case, one or more body parts are aching at the end of the day!


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