I'm not sure what you mean about trimming it to prevent damage. I have a couple of small Nandina in containers in my screen room ... I used to have lots of them in the yard, but they are invasive down here in Florida, so I got rid of the ones planted in the ground. I always pruned (trimmed) them in the Spring time, just to shape them and keep them at a decent size.
If your Nandina are large and you want to trim them up, I think you should wait until Spring when all chance of frost has passed. Otherwise, they will want to put out new growth and if you have severe cold it could damage or possibly kill them.
Hopefully someone else will jump in here with suggestions, because I am not an expert by any means and the statement I just made may not be the case in your area. I have heard that Nandina is a very hardy shrub, so maybe pruning at this time of year would not harm it.
Anyone else out there with ideas or information? ...
edited to say: WELCOME to Dave's! You will LOVE it here! There are so many generous, kind folks who are so helpful!
I agree about waiting until spring, if you prune them now you are likely to stimulate new growth which will be damaged if you get cold weather. Since they have flowers in spring or summer followed by berries, no matter when you prune I think you stand a chance to lose either the flowers or the berries for a year (I'm not sure if they bloom on new growth or old growth--if it's on new then pruning first thing in the spring is the best). Personally I never pruned mine--at least the varieties that I had tended to be plants that did fine when left on their own.
As nandinas grow, their stalks grow longer and become bare at the bottom. They can become kind of ugly at that point. I wait until spring, and then cut back about 1/3 of those older stalks down to about 15 inches from the ground. Usually they will send out leaves from that point, filling in that legginess. Each year I cut another third. That kind of keeps up with that leggy growth. I never trim them on the top. They are meant to be lacy looking, and that just plain makes them ugly, in my opinion.
I, too, did not understand what you meant by "to prevent damage". What damage?
The Nandina is a welcome garden plant in my region.
The plant looks graceful with purpish green foliage all year around,
and bright red berries through fall to winter.
People like to grow it in the yard corner or close to an artifical hillside,
or make it into kind of bonsai.
Talking about the prunning for BONSAI Nandina,
You can do a prunning once every three years.
And the best time for it is in spring.
You can cut off parts of the aged roots,
add some new nutriental soil into the pot
and at the same time, do some prunning:
Take off the slim, withered and pest-infected stalks,
thus forcing new sprouts to come out.
Generally, saving 3 - 5 stalks is okay.
Hope my suggestions will give you some help.
Good luck to your gardening.
Tenn ~ I suspect Nandina could suffer from frost damage in colder climates? I prune in spring also and similar to CJ, I select one third of the stalks and cut 2/3rds of the stalk off. One third of the stalks I cut 1/3rd of the stalk off and the other third remains uncut. If that doesn't make sense to you, please ask... anyway, this will make the nandina a fuller shrub.
...and a big WELCOME to DG, we are glad to have you! pod
Jianhua: Great post about Nandina in your country! I have one Nandina in a container in my screened room. I may have to take it out of the pot it's in, trim up the roots and try my hand at Bonsai ... I have always loved Bonsai plants, some people are so talented at it. Many years ago I tried my hand at a small plant, with the copper wire and bending and wiring the branches. I don't remember what became of that plant, but I guess I didn't have much Bonsai talent or the plant would still be around!
Nandina is native to China and Japan,
and in my region the 'southern heavenly bamboo',
as we Chinese say, are seen grown
here and there in the gardens and parks.
The glorious season of the plant is during the period
of fall and winter, when clusters of bright red berries
appear among the purplish green foliage.
it displays a mass show.
So I say, there is no need to trim the formed bush.
But for nandina bonsai, you have to repot your container
once every three years, just like I said above.
Trimming a nandina bonsai is relatively easy,
What you need to do, I think, is patience.
I hope to see your nandina grow well.
for the pictures, go to dave's garden,
look through my diary Dece/Nove issues.
Down here Nandina - all varieties from super dwarf to tall - are very easy to grow. Plant them and they grow...and grow and grow to the point that if you don't prune, the roots produce underground yet another plant. We generally prune out the older growth at ground level and cultivate deep to prevent the roots from establishing another plant (unless you want to dig that extra plant to put somewhere else or give to someone else). To me the prettiest feature is the leaves which have different colors at the same time. The flowers and berries are inconsequential to me, at least. Remember that Nandinas are a BAMBOO which is known for its invasiveness. Even the clumping type Bamboo. I am presuming, of course that Nandinas act the same no matter where they are grown so let me reiterate that what I have said is for my general area. Enjoy them. They don't require much care and provide a different texture to the garden.
Yes, it's related to barberry and not to bamboo, but it's still invasive in some places. I think most of the complaints I've seen about it being invasive have come from the south/southeast parts of the country.
True is it that the Nandina is aggressive
where the climate is extremelely hot,
but not in my region (Z6b).
Gardeners grow cactus for enjoying its prickles,
clivia for enjoying its graceful foliage,
and nandina (mainly) for enjoying its berries.
My friend Mr Wang Yong, whose yarden
is dominated with the Nandina.
Recently I dropped in his
Finding clusters of N.berries
still flashing their bright red hue
under the sun
in the cold winter.
I took a pruning class from the Master Gardener that runs the city gardens and he said that you ONLY trim nandina the way it is stated above: from the bottom, one third each year as necessary. We have several in our yard and the one next to the driveway only gets trimmed as it begins to attack our cars and then only in the spring. It's a big bush and very pretty and in full hot blazing sun. The ones on the other side of the house are in complete shade and are just as pretty. I never see the birds eating the berries.
I'd just like to add that pruning of Nandina should be done in early spring. Here in S.C. I was taught years ago to do this in late January. I've always done it that way and had good results. Although the birds do seem to spread the berries, the little volunteers are easily controlled - at least in my garden. (Z8)
This is interesting information. Even though I am in Florida, I love Nandina. Mine got out of control, not invasive, just too large for the spot. I removed them, but kept one on the side of the house by the air conditioner. It has more room here. It's an easy, pretty plant.