Tag: pruning

How to Prune Roses

How to Prune Roses

Good advice on rose pruning should really begin with a question: why? Why should you bother cutting at all? What would happen if you didn’t prune your roses?

  • The shrub might get taller than you’d like. You want blooms at a height where you’ll enjoy them
  • Left to their own training, they may take on an unattractive or uneven shape. They can also invade the space of another plant or intrude on a pathway
  • Dead, damaged, diseased & crossing stems will persist on the shrub, doing no one any good
  • The shrub may become a bit congested with older stems, preventing proper air movement and sunlight from reaching the center of the shrub

By the way, these are the very same reasons you’d consider pruning any tree or shrub:

Size. Shape. Health. Thinning.

And when you prune for those 4 reasons, you’ll often spur on vigorous new basal growth for stronger stems and flowering.

If your rose is younger, and still needs time to establish – skip it. Likewise, if your established rose is a pleasing size/shape, and overall healthy you can get away with minimal pruning. I usually pick an older stem or two from the base for removal anyway, just to encourage fresh growth, but it’s totally optional. I want to include a video here that shows how I tackle this in real life – first with a rough cut for size and shape, then with the finer work down low on the shrub to thin and remove old and damaged stems:

I could just about end the article right here, but I won’t. There will be questions about when and how, and I don’t mind answering them in full, but I don’t want to give you the impression that it’s a complicated matter. You could pretty much tackle your rose pruning when it’s convenient for you and use a wide range of methods (including a hedge trimmer!) and so long as you’re making progress towards one or more of the above goals, it’s all good.

Irritatingly, some of the specific instructions about rose pruning you’ll have heard passed around as garden folk wisdom is fixated on what I view as irrelevant and maybe even unhelpful: the cutting angle, the position of the cut in relation to the next outward-facing bud, sealing the pruning cuts. As a side-note, this video where I made commentary on these “rules” for pruning roses more or less launched my YouTube channel:

I’ll quickly summarize and review these supposedly rose-specific rules here and also give you my assessment of whether the rule is worthwhile:

1 – Prune when the forsythia is in bloom (late winter): Somewhat agree. It’s a pretty good time to target because you’ll be able to take out any noticeable cold damage in the same step. That said, you can prune later in the season – even after flowering, and that works well too.

Forsythia in bloom, but you could also time with many other late winter blooming plants

2 – Begin with dead, diseased, damaged or crossing stems: Mostly agree. It’s one of the main pruning goals I identified at the top the article. It’s also some of the most productive pruning – you can do a lot of good without any hard decisions. Whether you tackle this before or after shaping/reducing size is your call. In my actual work flow I generally take off some of the extra height and mass first so that I can get a clear look inside the shrub for these finer cuts.

3 – Prune to an outward-facing bud: Mostly disagree. This advice goes on the mistaken assumption that your rose will only shoot from the bud just below your cut, and that choosing an outward-facing bud will promote a more open shape after pruning. In practice, your rose will likely shoot from multiple buds below the cut, and will fill in with stems and foliage wherever there’s sunlight available to fuel the growth. Choosing a bud to be outward is unnecessarily fussy in my view, and this advice just serves to confuse new rose growers.

4 – Prune low and to just a few stems: I somewhat disagree with any one-size-fits-all guidelines around number of stems and standard height after pruning. I suppose it’s meant to reassure new growers that if they follow the recommended height for a hybrid tea or floribunda, that they won’t mess it up. The pruning height and shape shown in the video (open, and down to 18 inches) is pretty typical of the advice given. It’s probably fine for a healthy, vigorous shrub rose like a Knock Out. Many of my roses would resent such a severe cut, and I know many gardeners who prefer a larger shrub in the garden.

Photo by Malcolm Manners CC BY 2.0

5 – Use clean, sharp tools and disinfect between roses: Agree. This isn’t so much a rose-specific tip as just a generally good gardening technique. Cleaner cuts are less prone to die-back, and disinfected tools reduce the risk of spreading pathogens between plants.

6 – Cut on an angle and seal your cuts with glue: Mostly disagree. I couldn’t find anything before (or even since) the video to back up the notion that cutting on an angle is helpful, and what I did find in the research seems to indicate the opposite: the larger the surface area of the cut, the more it’s associated with poor outcomes.

This next bit gets me into hard feelings with some gardeners. If you think it’s worthwhile to seal your canes, I won’t stop you – and you can even skip to the next paragraph if you’re happy to keep doing so. Sealing the cut with glue (or nail polish or pruning sealer) isn’t something that’s likely to protect your roses from serious cane borer damage. The most damaging of cane borers on roses don’t enter through the cut stems, and they’re not flying around in the late winter (if that’s your timing) waiting for you to prune. Your best defense against the worst of the cane borers is careful observation during their active season (generally mid-spring to early summer) to quickly identify and remove infested stems.

Do I really mind you if cut on an angle or put nail polish on your cut stems? Of course not. You do you. My only point is that when these nitpicky practices are listed as the “right way” to prune roses, it adds complexity to an already intimidating task.

7 – Prune to a pleasing, balanced shape and a more open center. Yes. Let’s not overcomplicate the issue. A rose is just like any other shrub, and usually only needs a bit of thinning and shaping for best garden performance.

Common Questions

When I’m presenting this topic at pubic events (garden clubs, etc.) this is the point where the audience begins asking more specific questions. For convenience, I’ve answered most of these in video format at one point or another, so I’ll add those video and some commentary below.

Timing: As mentioned above, you can get away with pruning your roses over a wide stretch of the season. It does bear saying that once-blooming roses (species and some old garden roses) depend on their established stems for flowering, so an ill-timed severe pruning will result in a much less impressive display. Here’s a video (and flowchart, for those inclined) to help you work through the best time for puning:

What about climbers? You’ll improve flowering by keeping some longer stems in place and trying to train those stems horizontally. I’ve made two videos with examples, but here’s the one where I talk about it more generally:

On a similar topic, some viewers look for a little guidance for dealing with standard or tree roses. They’re top-grafted, so care should be taken to avoid damaging the graft union at the center. Here’s my video:

Finally, I hear a lot of questions about roses that have been neglected, and over the years have become overgrown. If they’re overall healthy, they can accept quite a severe pruning to bring them back down to size. I’ll include one final example video here just to embolden you to take up the loppers:

A few final thoughts:

If you’re in a temperate climate and you’ve chosen to take on your pruning at the traditional time of year, late winter, it would also be a decent time to do a bit of clean up. You could remove any persistent old leaves that haven’t dropped. You can also remove dropped leaves from the base of the plant, so that they don’t carry over the foliar disease from one season to the next. A refreshing or replacement of the mulch would be helpful in this regard too. I personally make my first application of bulk organic amendments at this time – I use alfalfa pellets a lot, but I’d be just as satisfied to apply a shovel scoop of compost or manure.

Avoid These 3 Things To Help Your Roses Survive Winter

Roses are built to survive winter

Don’t treat your roses like they’re the fancy dinnerware of the garden. Most are descended from tough, northern climate species, and they’re well prepared to get through the cold of fall and winter – at least in the mild-to-moderate climate of the Fraser Valley. Some of the “special care” that gardeners offer their roses in the lead-up to winter can, in fact, be detrimental to their survival. Don’t kill your roses with kindness! Avoid these 3 mistakes to give your roses a fair chance to survive:

#1: Late season pruning

Lock those pruners and back away from the rose… slowly. It may be tempting to give your roses a good cleanup going into the fall and winter. The leaves are yellowing and falling, the flowers are spent, and the stems are untidy – if not downright overgrown. You might think that your rose has a better chance if you cut it down lower, and send it into the winter with clean stems. You’d be wrong. Let me say this unambiguously – before winter is the wrong time to do structural pruning on a rose.

Why? Look at what winter damage on a rose looks like:

The stems are blackened at the top end – the most exposed tissue to the cold and drying winds of winter. The length of cane damaged will depend on the hardiness of the rose (many varieties have some sub-tropical genes bred in to promote reblooming) and the severity of the winter. In a mild winter, it may be only a couple of inches – in a severe winter, I’ve seen the damage exceed 18 inches!

Now I ask you: if you left your rose unpruned at 3 to 4 feet of height, and you lost 18 inches of stem in a severe winter, how would you feel about it? Not bad, probably. You were going to prune for shape and structure in the spring anyhow. Now how about if you pruned it back low  before winter – say to 18″ from the ground? If the winter damage reaches all the way back to the crown, it’s game over.

As an added advantage to leaving your rose a little untidy over the winter, birds and other wildlife depend on the rose hips and canes for food and protection.

I will add an exception now, just for completeness: there’s no bad time to remove dead or diseased wood from the rose. Also, if there are a few stems that have grown well above any support, and you know that they’ll just blow around and break in the wind, go ahead and prune them back to a reasonable length.

#2: Late season fertilizing

This one is a little counter-intuitive. It seems like a good idea to supply your plants with all the nutrition they need before the harshness of winter. A late-summer or fall application of fertilizer, however, can send your rose the wrong signal.

Those sub-tropical semi-evergreen rose genes I mentioned in passing come back into play here. Some of the best reblooming roses have a tendency to push new growth late in the season. They’re opportunistic growers. If the weather suits them, they’ll keep growing. As of today, November 19th, I still see a dozen or so roses in my garden cheerily flowering and sending up new growth.

In addition to mild weather, they’ll also grow in response to ample feeding and to heavy pruning.

That soft growth has no chance of hardening-off before winter. By far, you’re better off leaving the fertilizer until spring. Here on the rose farm, I stop feeding my outdoor roses in August.

#3: Deep Winter Mulch

The practice of hilling soil or mulch over the crown of a rose is a carryover from advice given to gardeners in very cold winter regions when trying to overwinter roses that are not well suited for their climate. It doesn’t apply well here, and from what I’ve read, it should be applied with caution even in colder climates. Read this article from the University of Illinois Extension for a good description of these methods. The emphasis is on not trapping moisture at the crown of the rose.

I don’t winter mulch anything. We take -10 celsius with heavy outflow winds, and my losses have been minimal. I’m crossing fingers and knocking wood as I write this, but I’m also quite sure that in our wet climate, anything that could hold water against the crown of my roses is not worth the risk.

 

For those who are more visual learners, here’s a video I made on the topics discussed above:

Overwintering perennials

Even if you only know me casually, you’ve probably caught on that I’m a bit of a plant geek… I mean, more than just the roses, tomatoes and squash. In fact, my real expertise (at my day job) is regarding perennials. I’ve learned a lot there about how to grow each crop to finish for sales in the spring, but the trickiest growing is on those crops I have to tend through the winter.

I made a quick video about it:

When it really comes down to it, the tricks to successfully overwintering any hardy plant in a container are pretty similar:

  • Start with clean plants – remove dead and diseased foliage early to avoid later problems
  • Protect them from cold winds that would dry their tissues
  • Shelter from the coldest temperatures. For some of the less hardy plants, this may mean heating – but for many perennials in the mild winter climate of the Fraser Valley, this just means a layer of protection (snow, crop cover, or an unheated greenhouse)
  • Try not to let your greenhouse heat up during sunny days
  • Provide decent air circulation
  • Don’t keep the plants wet all the time, but do water ahead of the coldest weather to prevent desiccation
  • Even if you start with clean plants, do inspect them frequently for any signs of disease or rot. As foliage dies down, in most cases, it’s advantageous to trim it away from the plant

And because this is a website about roses, I’ll add this: while I don’t recommend much winter pruning for roses in the landscape, I perform a moderate pruning on the container roses in my greenhouses. Where they have a little protection, they tolerate the winter pruning fairly well – I combine the pruning with stripping off the old foliage. This sanitation protects from winter rot, but also gives new foliage in the spring a fresh start, with no old leaves to carry over black spot or powdery mildew.

And here I am, enjoying a sunny January day in our garden! The days have been getting longer since December 21 – but I recently heard a climatologist quote a different measure: the dead of winter, which sounds more ominous than the way he explained it. The dead of winter, measured by local weather history, is the point in the year when your area has the very lowest average temperature. Every day after that is statistically more likely to be warm. I can buy into that! Here in the Fraser Valley, it’s around January 4th.

So we’re over the hump. As a rule of thumb for me, I begin seeing my greenhouse plants wake up around Valentine’s day. There’s still a lot of winter that can happen in a month, but it’s nice to have the finish line in sight.

 

Spring tidy and fertilizing

In the succession of flowering times for garden shrubs, the Forsythia comes early, and perhaps because it’s such a bright (or even objectionable, depending on who you ask) shade of yellow, rose growers use it as a reminder to get out there and prune their roses. If you lack a Forsythia, you definitely use the more attractive red-flowering currant here in the Lower Mainland, and it wouldn’t much change your timing. I snapped a picture of my inherited Forsythia this week… and as you can see, I’ll never miss pruning time:

The red/pink flowers in the foreground are quince (Cydonia), another shrub you could use to get nearly the same timing – it’s probably a week behind in my garden.

The reason many rose gardeners wait until this part of spring is that it coincides with roses being ready to break dormancy. By this time, winter kill on the canes (evidenced by black tissue higher up the extremities of your roses) will be apparent, and you will probably be able to see some of the buds swelling.

How to prune them? It depends on the rose, and it depends on what you want. This is your first chance of the season to influence your rose. Cutting harder usually means that the rose will respond with a number of strong shoots from the base, and will result in more flowers this season. A lighter prune allows the rose to grow and harden more canes, and if done properly, will allow some varieties of roses to form into a better garden shrub over the long term.

You can try to use this spring pruning and fertilizing to keep your roses a preferred size in your garden, but your influence is limited. I’ll put it this way: you’ll never make a small rose grow like a large rose by fertilizing, and you’ll never make a large rose grow like a small rose with pruning.

No matter your goals, it’s good to cut out dead, diseased and congested growth. And because roses are heavy feeders, they’ll respond well to a top dress of fertilizer or compost. A moderate amount of pruning and fertilizing will always leave your roses better off, and so I don’t get too hung up on the details… not even which other plants are blooming at the time!