This is a question most of us pros have come to dread. Not because we dislike answering questions, but because the subtext is so often, “I want a particular tree, but I don’t have room for it. May I have your professional go-ahead to hack the holy hell out of it to keep it to size?”

The answer is no. We love you and want you to be happy, but no.

If you have to hack the holy hell out of something to keep it a reasonable size and shape for your garden bed, then nobody is going to enjoy the process.

Not you, who needs to get out there to prune every eight months.

Not your plant, which will begin to create crazy long shooty growth in response to being hacked, and will eventually get aphids or just develop a terrible form from being pruned in such an unfortunate fashion.

And not your friendly local gardening professional, who will cringe every time they drive by and see the poor plant struggling unsuccessfully to fit our human expectations of how big it should become.

Rant over. Now here’s a helpful rule of thumb:

In general, you can keep a plant pruned 1/3 smaller than the tag says it will grow.

So if the plant tag says:

• 10 feet tall by 6 feet wide, read that as a minimum mature size of 6.5 feet by 4 feet wide
• 12 feet tall, read that as minimum 8 feet tall
• 15 feet tall, read that as 10 feet tall
• 20 feet tall, read that as 13.5 feet tall
• 25 feet tall, read that as 17 feet tall

That is truly the limit on how far down you ought to prune, and even then you’ll need a modicum of pruning skill to make that happen in a graceful way (check out this book if you need help and advice). But yes, in general, you can keep a plant 1/3 smaller than it wants to eventually grow, without sacrificing the flowers, growth habit and character that made you want to plant it in the first place.

If your plants don’t fall within that 1/3 limit, I’d definitely advise that you select a different plant for the spot, or even be willing to remove a plant if it becomes clear it’s wanting to grow far larger than the space you have for it.

It can really ruin the feelings you have for your garden when you are tied to an endless cycle of too-often pruning, or when you have to look at a shrub that vacillates between overgrown and heavily pruned. Particularly if it’s a plant you have a special affinity for.

There are so many gorgeous plants in the universe, it’s way better to get creative and choose one that will thrive in the space you have for it.

Further reading:

How far apart do I plant things?

Lenten roses, Helleborus orientalis, are gorgeous in winter. They’re gorgeous in spring, too.

But if you don’t deadhead them once they’re done blooming, they stop being gorgeous and start looking ratty.

Then, they turn into spawning hellcats, dropping masses of seeds that sprout into masses of tiny, slow-growing, hard-to-remove seedlings that, yes, could theoretically turn into fresh new hellebores if you wait ten years, transplant them into better locations, and coddle them, but practically speaking, will look like weeds and use up the water and nutrients meant for your parent plant without giving anything substantial in return.

Deadhead them.

It’s simple: if a stalk has a bloom on it, cut the whole stalk down to the ground. You’ll be left with a lovely mass of foliage.

Then, in winter, when the blooms come up, you do the opposite: cut out any stalks that are obviously last year’s leaves (there may be a few brand-new leaves coming from the base, but those are easy to spot and leave be). Your Hellebore will then look like this:

Easy, right?

If you’re a Humboldt County local and you need help getting to all of this, give me a call. My pruning and fine perennial maintenance crew is happy to take care of all of these things at the right times of the year, so that all you have to do is relax and enjoy your space.

More about Hellebores here.

There are two schools of thought on pruning Lenten rose, or Helleborus orientalis. One side says to prune off the old foliage to the very base just as the Hellebore is starting to flower.

The bloom spikes start coming up in the center of the plant, and the old foliage lays down obediently:

If you prune it at this time, your new flowers will unfurl with the naked, innocent look of a woodland bulb – all stem and bloom:

And if your Hellebores are really plump and happy, you might not even miss the foliage:

Of course, some people don’t like the minimalist look on their Hellebores, and prefer to leave the foliage as long as possible:

If that’s you,  just keep an eye on things and prune out the old foliage when new leaves start to come out, about two months after bloom starts.

If you miss the boat and let the new foliage emerge among the old foliage and the flowers, you get a mess, and it is hard to prune out the old stuff without harming the new:

Hellebores are lovely, easy-care plants that rarely get a disease, but they do not like being crowded. Plants that look like the photo above often suffer snail damage, sooty mold, and whitefly, none of which will kill the plant, but sure isn’t attractive.

The winter cold can kill off these pests, so if you do prune off the old foliage right away as the flowers are emerging, it takes away the hiding place of any garden snails and kills off any whiteflies or mold that may be hanging about, ready to get a foothold.

Whichever way you choose to prune, you should take off your Hellebore’s old foliage between January and April, and also prune out the dead flowerheads when the flower color becomes dull and the seed pods in the center of the bloom begin to enlarge.

Hellebore flowers make a lovely display in a vase, even when they’re fading, so if you’re having trouble taking the plunge, just cut them and enjoy the last couple weeks inside.

They spread at an almost alarming rate via seed, coating the ground quickly with shiny baby Hellebore sprouts that are a terrible pain to remove. Unfortunately, it takes a really long time for Hellebores to do anything from seed – many years, in my experience, and the seedlings are random colors, so they may not be just what you were hoping for. That’s why I usually deadhead mine and just buy new Hellebores when I want them, so I can choose which colors and styles I actually want.

Want to read more about pruning Hellebores? Frances at FaireGarden prunes hers every year and shares the process with us.

More pruning tutorials here.

Ready to prune your Miscanthus Grass? This is the time of year to do it! Ornamental grasses start shedding little grass bits everywhere in January, and with every windy storm they become increasingly messy until in early March you have a bunch of grass sticks still upright and grass leaves piled up everywhere in your garden BUT on your plant!

You also want to prune now because if you wait too long, the new growth will begin to emerge from the base and when you whack the old growth, you’ll also trim the new shoots, which is no good.

I’ve written before about how to prune ornamental grasses – which ones you ought to whack and how, and which you ought to leave be. The Miscanthus grasses are pretty much all in the “whack” category, except for M. transmorrisonensis, the Evergreen Miscanthus that still looks green and fresh in winter. You needn’t prune that one!

Here’s a quick tutorial on how I prune Miscanthus Grass in winter:

The “before” shot. It’s very pretty, but what you can’t see are all the grassy leaves that have piled up around the neighboring shrubs. Mes-sy!

First, I use some rope to tie up my Miscanthus Grass so the stems and leaves don’t fly every which way when I start to cut.

Once the grass is neatly tied together, I use my trusty Fiskars Hedging Shears (video review here) to cut the entire thing back to 6 to 10 inches tall.

The Fiskars Powergear Shears cut thicker stems than most handheld hedging shears do (most hedgers are just meant for delicate leafy growth like Boxwood), so they’re great for cutting things back at this time of year.

You could also use electric or gas hedgers, but doing it by hand is safer and takes me about 60 seconds per grass, so using the power hedgers isn’t a huge time-saver.

Once it’s cut, you can lift the entire bundle of grass and take it to your compost pile. Simple, no?

Related reading:

How to prune other types of ornamental grasses in winter.

If you’re tired of cutting your grasses back every year, here are my suggestions for some winter-interest grasses that don’t need pruning.

How to summer-prune your Miscanthus grass.

Right now it’s major big time pruning season here in Northern Cali. I’m cutting back hardy perennials, roses, fruit and other dormant trees and ornamental grasses.

But there are a few things I’m leaving alone for the time being. A lot of my favorite plants are frost-tender and can be killed by a stern frost this time of year. For some of these plants, the old, dead foliage and stems are providing just an extra degree or two of protection for the tender new buds and shoots coming along for next year.

Dormant Mexican Bush Sage or Salvia leucantha

See the tender new shoots inside? The old stems help protect them from frost damage.

If you can hold off, don’t prune these frost-tender plants until after last frost, which here in Humboldt County is around mid-May:

Salvia leucantha or Mexican Bush Sage (and other tender sages)

Fuchsia thymifolia or Fairy Fuchsia

Lemons and other citrus

Brugmansia/ Datura or Angel’s Trumpet

Loropetalum chinense or Fringe Flower

Ginger

Tibouchina urvilleana or Princess Flower

Passiflora or Passionflower Vines

Pelargoniums or traditional Geraniums (Hardy Cranesbills/ true Geraniums are fine to cut back now)

Polystichum polyblepharum or Tassel Fern

Dicksonia antarctica or Tasmanian Tree Fern

Further reading:

Pam Penick from Digging has some tips on what to do with tender plants and particularly Agaves that have frozen and become mushy.

Rebecca Sweet from Gossip in the Garden has a great tutorial on protecting tender plants from the cold.

Sedum ‘Autumn Joy’ is a true garden classic, especially paired with ornamental grasses, lavenders and colorful sages.

It’s particularly great because during the summer when everything else is blooming, its greenish-white buds are getting bigger and bigger, creating a subtly beautiful show, then as everything else slows for the fall, ‘Autumn Joy’ bursts into bloom with a cheerful pink color that looks great with the fall colors on the other plants.

In this video, I’ll show you how to prune it, using my favorite Fiskars Powergear Hedging Shears (video review here). If you possibly can, wait until late January or so to prune to allow the birds to enjoy eating all the seeds it provides through the winter. I pruned this one early since it’s by the front door, but I’m setting the seedheads on my compost pile to encourage the birdies to scratch around.

If your Sedum was floppy this year, it’s a good sign it is either getting too much shade, or that it needs to be divided. To divide, dig it up, use a sharp shovel or hori-hori to cut the rootball into thirds or quarters, and replant one portion. Then you can make friends with neighbors by giving them your extra plants.

I’m a big fan of ornamental grasses because they add so much motion and life to a garden. If you use multiples, they’re an easy way of bringing a sense of continuity to a busy or scattered-feeling garden, because the effect of their foliage is so soothing.

Miscanthus is a favorite because it grows so fast, it’s bulletproof (just give it sunshine), and it always looks so exuberant and healthy. The downside to its enthusiastic growth is that late in the season it can start taking up more space than we imagined and begin flopping onto its neighbors.

I’ve seen people take out their frustration with their Miscanthus Grass by taking their electric hedgers to it and just shearing off an entire side of the plant, so the poor thing loses the graceful movement it had and simply sits there looking shorn and attacked. Please don’t do that!

In this video I’ll show you a quick way of pruning your Miscanthus Grass to make it smaller and less floppy if you are having that issue, and nobody will be able to tell you did anything except for the fact that the Miscanthus will now be smaller AND still pretty.

Of course, if you’re having to summer-prune the grass every year, it might be time to either divide your Miscanthus this winter by digging it up and replanting just a smaller portion (I do this every 5 years or so), or maybe you have chosen a grass that is too big for the spot, and a more dwarf variety of Miscanthus like ‘Yaku Jima’ (4’+) or ‘Little Kitten’ (3’+) would be a better choice.

I’ll add: if you love ornamental grasses the way I do and want more ideas on how to use them in your garden, you’ve GOT to get Nancy Ondra’s book Grasses: Versatile Partners for Uncommon Garden Design. Saxon Holt’s photography is simply gorgeous, and Nancy’s suggestions on how to use each grass gives me new ideas each time I read.

If you liked this article, you might also enjoy learning how to winter-prune your ornamental grasses.

I love Bigleaf Hydrangeas (H. macrophylla), the traditional garden Hydrangea with either big mophead flowers or the subtler lacecap flowerheads. Most gardens have a Hydrangea or two tucked in, and why not? As long as they have composty soil and get watered regularly, they make a fantastic show of blooms with very little effort on our part.

It’s coming up on the time of year to prune them in warmer climates where it doesn’t snow (right after they finish blooming is best), and I made a video and took some photos to show you how (if you live in a colder climate, you use the same technique to prune, only you’d do it in mid-spring to protect against frost damage).

Why prune? Scientific studies have shown that Hydrangeas that are pruned properly flower more than plants that are left unpruned. Pruning also encourages a fuller habit for the shrub and stimulates the new growth that keeps the plant healthy.

The video shows you how to do it, but here’s the basic idea:

Before pruning cut is made – look for swollen buds	After pruning cut is made, just above swollen buds

When you are ready to prune off your dead flowerheads, look along the stem for a pair of swollen buds at the base of each leaf. The first set of leaves below the flower rarely has these swollen buds, but often the second and third pair of leaves do.

Prune off every dead flowerhead to just above these swollen buds, taking care to leave the buds unharmed when you cut. Once you’ve cut off every dead flower to a part of the stem that has these swollen buds, stand back from the shrub and notice whether there are any shoots sticking up above the rest of the plant. Feel free to prune any of the other, non-flowered shoots to their own sets of swollen buds to give the plant an even, rounded shape.

After you’ve pruned the entire shrub in this way, you can look inside the shrub to see if you want to remove any of the oldest branches which are least likely to flower. If you remove one quarter of the oldest, woodiest branches each year by pruning them out as far down as you can, it keeps the plant rejuvenated and ready to put out fresh young stems which will flower more for you.

You can also prune out any stems that are so spindly they wouldn’t hold up a flower, and any stems that are dead with no leaves. I love to do this kind of regenerative pruning at the end of the summer when you can still see what stems are alive. Once the plant loses its leaves for winter, it’s harder to tell what’s dead.

If you’re a fan of Hydrangeas like I am, you might enjoy Michael Dirr’s book about them. Hydrangeas for American Gardens profiles the most common types of Hydrangeas available, and shows off some unusual varieties as well. Some of the language in the book is a bit stiff and scientific, but Dirr keeps his sense of humor, too. I love this sentence where he’s discussing watering:

Hydrangea macrophylla, more so than any other species, will signal when drought-stressed, with leaves drooping like a scolded dog.

So true, Michael!!

If you’ve found this pruning tutorial helpful, check out my articles on how to prune Scotch Heather, which is also finishing up its bloom now, Alstroemeria, and Hardy Cranesbills/ Hardy Geraniums.

Edit April 2010: Debbie over at Garden of Possibilities has just written an excellent article on pruning Hydrangeas if you live in a colder climate. Check it out!
Note: There is a print link embedded within this post, please visit this post to print it.

I shot this video in December, when this Salvia was at the end of its blooming season and just starting to think about going dormant, but the advice for how to deadhead and prune it is still great for summer.

Right now, many of the Mexican Bush Sages in the gardens that I maintain are just starting to need deadheading or trimming back out of pathways and other plants.

If you need to trim your Salvia to make it smaller, the most important thing to remember is only trim it back as far as it has leaves – unless you’re removing stems altogether by cutting them out at the base, in which case just don’t leave any big bare spots.

The next thing to remember is that if you’re trying to trim it back out of a pathway or another plant, don’t just trim it on the one side that is overflowing – trim the entire bush if you’re going to trim one part, as otherwise the lack of tumbling blossoms on the trimmed side looks very obvious from afar.

If you enjoyed learning how to prune your Mexican Bush Sage, you might also like to learn how to prune Geranium ‘Rozanne’ and other Hardy Cranesbills, Alstroemeria, and Scotch Heather.

So every time I open up my pruning book to the raspberry page, I get deep unhappy furrows in my brow. Raspberries are a simple plant. Why do they have to make it so complicated?

There’s the summer-fruiting kind (with a short fruiting season), which fruit best on one year old wood. Ideally with these, you should prune out the canes that have fruited right after they finish (late summer/early fall) and leave the current year’s canes (the brand new fleshy green ones) to fruit the following year.

Then there are autumn-fruiting raspberries (with a longer fruiting season) , which fruit on the current season’s growth. You aren’t supposed to prune out the fruited canes right away like with the summer-fruiting ones. Instead you cut every cane down in late winter when the plants are fully dormant, and allow all new canes to come up in spring.

The problem is, most people have no clue which type they have.

So I was pleased to read recently that there’s a simple rule that works for both varieties: In winter, just remove any canes that gave you fruit, and you are good to go. The stems that once held fruit will still be clinging to the canes, making it easy to tell.

If the vast majority of canes fruited last year, it’s likely you have an autumn-bearing variety. Don’t be alarmed if you basically cut the lot of it to the ground.

If only some of them fruited last year and the rest of the canes seem green and fresh, it’s likely you have a summer-bearer. Either way? The simpler rule of pruning works fine.

Hope that helps you feel confident to get out there and prune your raspberries!

(By the way, the same rule is good for Boysenberries, Blackberries, and Loganberries, which all fruit on one-year old canes – just prune out the canes that fruited for you, and tie the fresh new ones to your trellis! Simple, right?)