— Archived thread.—

Posted by TamaraVa z7bVa on Wed, Jan 8, 03 at 15:20
Hi everyone!! I need some input on some perennials that HATE to be divided. Last year I hurt my back so I am slowly converting my garden into a no divide zone.So far I have planted Baptisia,callihoe,Russian sage,and Iberis along with my shrubs.It is killing me to let go of my ornamental grasses(any ideas on a grass that wants to be left alone?)Asclepsia's are too buggy for me...always covered with aphids.Too bad,one year I had a bumper crop of monarch butterflies.Thanks in advance for any input.
Tamara

Posted by: iann z8/9 England on Wed, Jan 8, 03 at 17:57
Iberis sempervirens? No need to divide it but you will need to cut it back after flowering. Sounds like a lot of bending down.
--ian

Posted by: Taryn S Ontario Z6B on Wed, Jan 8, 03 at 19:15
Peony
Papaver orientale
Helleborus
Dicentra eximia

Know the feeling....
Taryn

Posted by: Tim_Sullivan z4NY ) on Wed, Jan 8, 03 at 19:22
Peonies, astilbe, Japanese anemone, ligularia "the rocket". lilies, daylilies, sedums . . . but here is a question: why do you feel you have to get rid of your grasses, etc? Surely you know people who would like a piece. Just invite them to come and take off a piece or two. Your grasses are still around, they're contained and someone else is very happy.
Also, maybe try planting things that spread in five-gallon plastic buckets with the bottoms cut off. We do this all the time with things like mint and it works.
Tim
Posted by: Laurie_KY6 z6 KY on Wed, Jan 8, 03 at 20:05
Astilbe? Now you tell me. My 'bible' on dividing (The Well Tended Perennial Garden) recommends dividing astilbes every 3 years or so. Sure enough, mine were huge by the third year. They were one tough job. I had to take a sharpened spade and jump on it to split the 'bulb'. I'm anxious to see what the divisions look like in the spring. Even cut in half, I had large astilbes to replant.

I did a lot of dividing this fall and do not relish doing it again in the near future. Posted by: TamaraVa z7bVa on Wed, Jan 8, 03 at 20:30
Thanks Laurie,I have to get that book (the bible).I just remembered she has a wonderful list in the back for just this subject. What does she say about echinacea? Now,Tim, can I really leave the grasses in the ground and just thin it out? I thought they died out from the center? Boy that would be great if I could just dig around a bit.I certainly don't have the giants of the grass world.I have Panicum"shenandoah" 4 ft tops and Muhlenbergia capilliaris( which I wouldn't give up, I'll pay someone to divide if I have to!!)Schizachyrium "the blues"will be manageable.Daylilies!! I can really leave them be? You folks have save the day with your kind suggestions!!.I can still have my old friends in the garden with the bum back.
Tamara Posted by: david_5311 Z 5b/6a SE Mich on Wed, Jan 8, 03 at 20:36
Geraniums (cranesbills, hardy g.) rarely if ever need dividing. I have plants of some that are at least 10 years old and are cruisin'. The books say divide, but only if the plant indicates a need (and that won't be
often). Clematis, plant really well, wait, and they get good after 3 years, better after 10. Same with hellebores, Taryn mentioned them, you never touch them once they're in. Astilbes? I don't divide them unless I want more.

And don't worry too much about what the RULES say. I have been gardening with perennials for a long time and I don't divide plants that much except when I want more. Plants don't read the books after all. Think of division mainly as a propagation method and not a garden chore. Posted by: enchantedplace z6OK on Wed, Jan 8, 03 at 21:48
Platycodon (balloon flower).. Yes some hybrid day lilies do not need frequent division. Some lilies should also never be disturbed. We never divide our echinacea.
Posted by: Brody 7/8 snst4 WA on Wed, Jan 8, 03 at 22:03
Eryngiums, Gaura, Caryopteris. Sedges, like Carex pendula and Carex buchananii. Rodgersias, Cimicifuga, Columbine, Alstromeria, Kniphofia, Agapanthus, Campanula lactiflora. Lots more out there.
Posted by: Taryn S Ontario Z6B on Wed, Jan 8, 03 at 22:49
Got 'the bible' for Xmas and have it sitting beside the computer now. Re, Echinacea purpurea, author DiSabato-Aust places this in the 'perennials that may require division every 6-10 years' catagory, so that's not too bad. Although if you let some of the plants mentioned, including this one and Gaura, columbine, and other's on the author's extensive list go to seed, you'll be bending over pulling seedlings forever! Which won't help the back situation.

David, I've found even though I feed the soil regularly with compost and organic matter, that some plants really start to deteriorate and not bloom as well if they aren't divided fairly regularly. Coreopsis and Hemerocallis spring to mind instantly. Guess those ones can read, lol. Then there are others, like bearded iris and monarda, that will happily bloom away without divison forever. They'll just swallow your garden whole!

Get the book, it's a great resource. And check out the 'bummer' thread on conversations, might give you some ideas...

Taryn Posted by: Paul299 z4 Minnesota on Thu, Jan 9, 03 at 4:03
Astilbe should be divided ever four or five years-otherwise they become very woody and less likely to survive dry spells and flower less.

Hosta almost never need division to keep the plants happy. 20 years or more. I take it -- it's not a shady spot so I will not include the shade list:

Adenophora
Amsonia
Anemone
Artimisia
Aruncus
Baptisia
Campanula - many of the larger ones with deep roots
Dicentra spectabilis
Echinacea
Echinops
Ephorbia
Gypsophila
Hibiscus
Lathryus
Liatris
Lysimachia
Macleaya
Peony
Perovskia
Phlox paniculata
Physostegia
Platycodon
Rodgersia
Sedum -creeping types
Thalictrum
Tradscantia - many
Trollius

The above plants can be planted and left alone for many years with out a lot of work;

Here is a small list of plants that should be divided every two or three years:

Achillea milefolium hybrids
Aconitum
Aster- a few
Astilbe
Coreopsis lancifolia,grandiflora
Dianthus - a few but not all,
Gailardia
Geranium - on a number it will improve flowering
Heliopsis
Heuchera
Iris
Leucanthemum
Lobelia
Lychnis
Monarda
Penstemon
Salvia - some
Phlox-the shorter species
Polemonium
Ruddbeckia
Scabiosa
Sisyrichium
Tanacetum
Veronica

Nothing is written in stone, much depends how well you grow the plants and how long your growing season is. So this above lists are generalities. Posted by: TamaraVa z7bVa on Thu, Jan 9, 03 at 9:52
WoW, You have all given me plenty of options.I agree that gardening goes way beyond the books.For instance, I am always reading were Liatris Spicata does well in most places but I have managed to kill two of them.Further research leads me to believe it likes more moisture than I can provide.That is why I love forums , real gardeners telling real stories.
Thanks Again,Tamara Posted by: palmandan 4 Vermont on Thu, Jan 9, 03 at 21:09
"HUH? That list from Paul has artemesia, lysimachia, macleaya, physotegia and tradescantia as plants that do not need to be divided often and can be left alone for many years."

Yipes - NOT where I live. All those plants are aggressive spreaders for me. Interesting if they aren't for other folks. I was going to suggest heuchera (coral bells) - at least I have some heuchera palace purple planted in a circle around a sap bucket and they've been in the same place for 12 years. They self-seed, but it's easy to get the babies. I don't divide it that often. If you buy a REALLY expensive daylily you can bet it won't grow very fast :-) Posted by: david_5311 Z 5b/6a SE Mich on Thu, Jan 9, 03 at 22:03
One interesting thing I have learned reading this thread is that I mostly don't PLANT plants that require a lot of dividing. That's why I have the sense that most plants don't need it. I have few daylilies and they mostly aren't my cuppa tea. And yes, Taryn is right, there are a few other plants that probably have declined over the years as a result of my 'divisional neglect', leaving a HOLE, a SPACE in my otherwise crowded garden...
a great spot to try something new. And yet another reason not to fret too much about dividing plants.
Posted by: Paul299 z4 Minnesota on Fri, Jan 10, 03 at 7:44
"HUH? That list from Paul has artemesia, lysimachia, macleaya, physotegia and tradescantia as plants that do not need to be divided often and "can be left alone for many years.

"Yipes - NOT where I live. All those plants are aggressive spreaders for me."

That is why they do not need to be divided often -they will spread out and take care of themselves. Those plants that need division are those that grow to thickly and crowd them selves out and/or develop woody type stems or roots that do not over winter as well as "new" stems and roots.

These plant can be put in the land scape and be left to there own care as long as they have the room to spread out. And besides a large drift of one plant tends to look better that a jumble of many single but different plants.
Posted by: Paul299 z4 Minnesota on Fri, Jan 10, 03 at 7:55
" I was going to suggest heuchera (coral bells) - at least I have some heuchera palace purple planted in a circle around a sap bucket and they've been in the same place for 12 years"

From here in Minnesota have to replant Heuchera every three years, most of the time because they tend to grow out of the ground- that is the growing point of the stem keeps growing upward. Then during winter the stems that are above ground is killed off in March during our warm days and cold nights. Though I have 40 some Huechura (that I can not remember what they- one of the purple-red foliage types) that have been in the ground for about 8 years and they are still alive, but sure would grow and look better if I got in there and replanted them deeper.
Posted by: Marg504 z5PA on Fri, Jan 10, 03 at 9:32
May I add Dictamnus albus to the list. It resents being disturbed. Has attractive, glossy leaves. No disease or pest problems. The growth habit and size is much like that of a peony. Flowering time is only about 2 weeks in early to mid June, but the seed pods are attractive. I found it to be a pretty plant throughout the growing season. The drawback is that the lemony scented oils (Yes, the oils will ignite briefly when a lit match is held close) of the leaves can cause a skin rash on contact for some people. This happened to my dh when he mulched under the plants after scratching up his bare arms while mulching under the junipers. The lesson here is to wear gloves and long sleeves to mulch the junipers, not to ban the dictamnus from the gardens!

Posted by: TamaraVa z7bVa on Fri, Jan 10, 03 at 10:38
I also find in this area that Heuchera needs to be divided every other year or it disappears.In fact in this area I have never seen an impressive clump(except for H.Villosa).You all got me interested in Helleborus so
I went out to do some research.If I can keep up with the seedlings it sounds absolutely wonderful.I have come to the conclusion that the perennials that don't need dividing are the type 1)that need space to go through their waxing and waning and 2)can self seed vigorously.I will have to look up Dictamnus ,it sounds so lovely.Best Wishes,Tamara

Posted by: Johnnieb Washington, DC on Fri, Jan 10, 03 at 12:48
Peonies are the classic never-divide perennials. Siberian irises likewise make good clumps that rarely need division. But I wouldn't recommend bearded irises, which have creeping rhizomes that are best divided and replanted every 2-3 years (plus the foliage looks ratty after blooming).

Posted by: GreenGene on Fri, Jan 10, 03 at 18:13
Add hostas to your list. They almost never need it and look better if you don't. I've never tried any of the newer daylillies, but the older cheap ones spread way too much.
Gene

Posted by: sbeuerlein zone 6 on Fri, Jan 10, 03 at 19:15
For those of you bible thumpers (Tracy Disabato-Aust fans), you'll be pleased to know she has a new book due out very soon. I think the topic is about incorporating shrubs into the perennial border. has it listed as a future release.
Scott

Posted by: TamaraVa z7bVa on Fri, Jan 10, 03 at 20:17
Scott,I'll have to check that one out.I sat in Barnes and Noble the other day looking up all the great suggestions.Speaking of shrubs has anyone heard of Danae Racemosa.It has quite a history .The common name is
Poet's Laurel.The leaves use to crown Athletes,poets,and orators in ancient times.Plant history has always intrigued me.How could I resist? I went over to the shrub web and found out it is a member of the lily family and produces pretty red berries in the winter.It likes shade and grows to 3x3 and STAYS there.My kind of shrub!So,I'm thinking about pairing it with helleborus orientalis.Tamara

Posted by: Tiffy_z6aCan 6a on Fri, Jan 10, 03 at 20:28
Tamara,
...Antique roses don't need division... :) From another gardener with back muscle spasms and a reoccuring slip disc... :(
Nicole.

Posted by: TamaraVa z7bVa on Fri, Jan 10, 03 at 22:08
Oh Nicole, You understand So much!!LoL ;) (funny, my rose list has been growing over the past year)Tamara

Posted by: hoehum z5/6 PA on Sat, Jan 11, 03 at 8:40
The only perennial I've found that must be divided is Shasta Daisy -- they dend to die out in the middle after 3-4 years. All the rest just spread happily or stay put. Heuchera has a tendency to pop out. I either yank it out to give away or mash it back in during spring when the ground is soft and damp. My astilbe has never been divided. About 5 years ago I sliced off some edges to make more.

Posted by: laceyvail zone 5b, WV on Sat, Jan 11, 03 at 8:51
You mention that you have planted Callirhoe. I assume you put in C. involucrata because it is readily available. Little known and very hard to find is C. digitata. This is a gorgeous scrim plant, 4-5 feet tall on thin, pale, nearly leafless, grey-green stems, with the same wine cups up and down the stems. From a slight distace, they look as if they are floating. A great plant. Whenever I look at it, I can hardly believe it is not better known. Carroll Gardens is the only nursery I know of that sells it. Oh,of course, no division needed.

Posted by: TamaraVa z7bVa on Sat, Jan 11, 03 at 18:48
Laceyvail, Thanks for the info on C.digitata.I am a great fan of Callihoe and yes,my plant is C.involucrata. Funny thing is I planted it before did any research on it(besides the catalog description)Oddly, my huge Botanica "Bible" didn't list it so I searched through some other books.That is were I discovered it's long carrot-like taproot.Just in time because I was planning on moving it this spring.What I love is the way it weaves around its neighbors.I remember looking out the window one day wondering what that lavender bloom was on my panicum grass!I always hoped to achieve that with hardy geraniums but they hate our heat here.I agree with you.It's hard to believe the whole lot isn't better known.That plant bloomed for months and is still evergreen.It has a fascinating way of dieing back to the crown after flowering then coming back with gorgeous cut leaf foliage.My plant is the var.tenuissima(mexican wine cups).I believe they have one out called Logan's White,only I hate to pay Plant Delights shipping of 16.00 so I may look into your mentioned
callihoe.Thanks Again,Tamara

Posted by: katybird_PA z6 PA on Tue, Jan 14, 03 at 10:57
I don't think I saw it mentioned so I will recommend Lavender (especially
pretty with Antique Roses).