Cut back your platycodon grandiflorus?

Elgin, IL(Zone 5a)

I always read that grandiflorus plants (the tall ones) will not flop if you cut them back when they are about a foot tall. So I did it for the first time. I took them down to about 8 inches. The tall pink and white ones stand tall while my blue ones have always collapsed. So we'll see.

Sierra Foothills, CA(Zone 8a)

Donna ~ Any result yet?

Elgin, IL(Zone 5a)

The one that I didn't cut as a test has flopped. The others are standing tall and continuing to grow. I understand that this will simply delay the bloom. And they look a lot better standing tall!

Sierra Foothills, CA(Zone 8a)

I do the same thing with asters and tall chrysanthemums. I am also checking to see if I can do it with more perennials.

Elgin, IL(Zone 5a)

I checked them this morning. They are setting buds!!!

Elgin, IL(Zone 5a)

Yep, it worked. They are blooming without flopping - for the first time in YEARS!!!!!

Jackson, MO(Zone 6b)

I had not heard about the grandiflorus plants and cutting them back. So, all grandiflorus plants can be cut back. Hmm. Where did you read about that? Sounds like a great tip. My platycodon grandiflorus have pretty much finished blooming. I cut them back. They bloom again for me in the fall after I cut them back. It takes awhile, however.

Elgin, IL(Zone 5a)

I read about it many years ago but kept forgetting to do it. And every year my platys would flop, and THEN I would remember. The blue ones are far more prone to flopping than the white and pink, and it would be very noticeable.

This isn't where I got the tip but the ever wonderful Missouri Botanic Garden has it. I find it doesn't reduce plant height by very much. What it does do is delay bloom time by a couple of weeks, but I love it because I have always had to stake them, even in full sun, and this year I don't have to! They look wonderful!

http://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?kempercode=c282

This is different from the cut back you do to get rebloom. I do that too.

I gather information from 50 billion sources and make notes. What I finally did was put the cut back date on my calendar.

Sierra Foothills, CA(Zone 8a)

Donna ~ You are always so organized to the letter. However, my asters had been flopping for years, so I just decided to cut them back about July, and then they did not flop since then. I do that with my chrysanthemums also. I wish I could do that with my one flopping peony! Maybe I will just find a replacement for it.

Jackson, MO(Zone 6b)

I will put that in my phone calendar for next year! Thanks. Mine always flop. I really like the plant, or I would have gotten rid of it by now. I really like the blue flowers. Plus mine, in the fall, turn a bright yellow. That's pretty too.

Elgin, IL(Zone 5a)

Mine have bloomed and look fab. The few I missed are flopping on the ground. It's nice to have ones that finally look cool.

Jackson, MO(Zone 6b)

Yes, I will do that next year. Thanks for the tip.

Northeast, WA(Zone 5a)

just happened to see the subject you are discussing and had to jump in and tell you I do that with Dahlias so i don't have to stake them. Now have bushy plants and a lot more blooms. just not quite as big. Forgot to say i pinch them off when they are about 4 inches out of the ground. just take the middle leaves etc out of it like you pinch anything else.

Elgin, IL(Zone 5a)

That's interesting. It would not have occurred to me to do this with bulbous plants. I think I am going to try it on a few.

Thanks!

Donna

Himrod, NY(Zone 6a)

This has been stuck in my 'new' thread list. So maybe this will unstick it.
Joy

I will say I enjoy reading and have cut many of my plants back to bush them out more or just to contain them a bit.

Northeast, WA(Zone 5a)

I do it so I don't have to stake them. They bush and hold each other up. I would do it with any plant. might even try it with my roses, altho, it is so late in the year to try it that they probably would not bloom. might try next year.

Elgin, IL(Zone 5a)

I chop the heck out of my hardy salvias and nepeta in general. The blue nepetas get big and climb over everything, while the white nepeta just moves across the ground at a height of perhaps six inches and suppresses weeds without stomping on everything. I find that the pink nepetas like Dawn to Dusk and Black Stockings don't smother other plants. Salvia I cut down to the base foliage, and then it blooms again, even without water. Digitalis mertonensis will bloom again if I cut it back.

I have been dong it for the last few days and people look at me puzzled, because they can't figure out why I am cutting things with even spent bloom on them. But I have learned from client gardens that if you don't cut blue nepetas and salvias back they will seed and spread everywhere, and a lot of my clients have the earlier versions of these plants put in by landscapers, and they tend to be inferior cultivars with undistinguished flowers and very small leaves. And they have literally dozens of them.

It's really interesting. I garden for 8 people and the worst gardens are put in by professional landscapers. Grafted crabapples and pears that throw up endless wrist sized suckers, lots of autumn joy sedum, tons of various daisies that seed everywhere, peonies under the shade of evergreens (fungus diseases guaranteed!) invasive vines that destroy structures, grafted roses that turn into Dr. Huey, barberries near entertainment areas, and my favorite, filling up the yard (and their pockets) by putting shrubs so close together that every third one gets choked out and dies. Then I get to pull it out.

No, actually my favorite is the client who asked for Austrian pines, at least ten, and the landscaper did not tell them what every master gardener knows. There are losses and disfiguring diseases in most areas from these gorgeous trees. The excuse was that the client's husband asked for them, and the landscaper either did not know or did not care. I was dismayed to tell them that, not only could I not treat them (unlike the fungused peonies in shade - here comes the sulphur) but that I had to call in a specialist, and now they are sprayed at least three times a year, at the cost of several hundred dollars a year. They feel that they have no choice, because they are in a line that gives then privacy from a neighbor, and they are a good 30 feet tall.

I encourage people to go on line before they buy a plant. Do a little research. When I'm really lucky they ask me to go to nurseries with them (YES!) but the best nurseries will actually guide them away from problematical plants - for which I thank them profusely.

Pittsburgh, PA

I did some investigating years ago and compiled this article for the nursery, where I work Facebook page.


Cutting Back Plants for more bloom and height control

With all of the rain we have been receiving through the spring and early summer, many plants have grown tall and now are too tall to actually fit into many flower bed plans.

Certain perennial plants can be cut back at different times in the season to keep them “shorter” and bushier. Later blooming plants cut back in “early” (before the 4th) July will shorten the plant making it bushier, and cause it to bloom two to three weeks later than it normally blooms. This process can be used to “time” plant bloom, in order to fit into a party or garden tour schedule.

Plants that can be pruned for height:
Mums, Asters, Monkshood, Hibiscus, Joe-pye Weed, Helen’s Flower (Helenium), Beebalm (Monarda), Tall Phlox (Phlox paniculata), Tall Sedums, Catmint (Nepeta hybrids), Turtlehead(chelone hybrids), Veronica hybrids, Yarrow, Russian sage, Artemisia, Balloon flower, Dragonhead, and Culver's root.
Some plants do not respond well to pruning. These are plants with one terminal flower spike or plants with leaves in a low rosette rather than a long stem. The plants that should not be pruned include Columbine, Astilbe, Delphinium, Daylily, Coral bell, Hosta, Iris, Foxglove and Dianthus.

Most perennials bloom for three to four weeks at their appointed time, in the season. Many do have the capability to bloom continuously for two to three months!!!
If you want more prolonged bloom on your perennial plants, consider deadheading, the plant is not producing seed which, in some plants signals the plant to flower again. Remember to feed this plant to give it an energy boost to produce this second floral display, with a “bloom booster fertilizer” with a higher middle number, which is phosphorus that promotes the bloom.


Elgin, IL(Zone 5a)

What a great article!

I just did what you make reference to in your last paragraph. I had not thought it through the way you have, but I just spent the last week chopping away. It also helps me decide what to move. Now to go back and add fertilizer, as you suggest. My beautiful Campanula Bernice (one of my favorite flowers) gets clobbered by nepeta (what an enthusiastic grower!) every year, and at some point I wonder where the heck it is and chop back the nepeta to find the poor little Bernices, all bloomed out, at the bottom. I then liberate and compost them, but it is clearly time to move them. They cost a lot to acquire. The first time I got three for $12 from Bluestone. A couple of years later they were $16 EACH! Thank goodness they are survivors.

Thumbnail by DonnaMack Thumbnail by DonnaMack
Jackson, MO(Zone 6b)

obliqua: Good article. I have many of the plants you mentioned. I cut back dianthus hybridus many times throughout the season, and it blooms again and again. Digitalis has been known to re-bloom if you cut off the spent stalk, however, I don't because I like to save the seed and hopefully re-seed on its own which it does often.
I didn't know you could cut back hibiscus but I don't see a reason to unless it's for some sort of show you are working towards. Sometimes I cut back Nepetas. Usually, they bloom for me all summer long without dead-heading. Nepeta is one of my favorite flowers as they are so easy to grow, and they bloom all summer. I really like the soft grey-green leaves and the lavender blooms are so pretty with the grey-green leaves. Plus, the color of this plant goes with everything else. I use it at the feet of rose bushes and also as a border plant. It creates rhythm in the garden and unity.
Although I really like Campanulas, especially the biennial Campanula medium. It does not make it here: way too hot and humid.

Pittsburgh, PA

Check out "You Bet Your Garden", http://whyy.org/cms/youbetyourgarden a web site for a radio show from Philadelphia. Mike McGrath is a "jokester" and has great content in his show. Lots of information.
Something to listen to while I garden or work on my computer!

There is also a garden answers A to Z on the site, that is also a great resource.

Jackson, MO(Zone 6b)

Thanks for the recommendation. Always receptive.

Himrod, NY(Zone 6a)

I loved seeing Mike McGrath's name again. He was the editor of Organic Gardening years ago and he made it so fun and interesting. The OG people seemed to think he was too much fun or something and he left the magazine. I did soon after.

I am really enjoying this thread and all the ideas about keeping plants under control. Now if I could get rid of orange poppies, trumpet vine and goose neck loose strife. I would be a very happy gardener.

Jackson, MO(Zone 6b)

Poppies? I never want to get rid of poppies. What kind are they?
Goose-neck loose strife. I researched that one before I thought about ordering it. So glad I did. I don't think anything gets rid of it.
My problem is Cyperus esculentus, yellow nutsedge. I fight it all through the growing season and of course, it's a perennial and returns and spreads. :( :(
Somebody posted an herbicide for control but I can't remember where it is, and trying to do a search on this website is impossible.

Off topic.

Elgin, IL(Zone 5a)

Gooseneck loosestrife!!!!!

I recently wrote an article for Daves about that lovely stuff.

These picture is just a few blocks from my house.

Thumbnail by DonnaMack Thumbnail by DonnaMack
Elgin, IL(Zone 5a)

Speaking of platys, I just germinated some white ones. They are surface germinators. At 70 gedrees it only takes a few days.I got some perlemutter ones into the ground earlier. The only catch is that you have to let the seedlings get fairly hunky.

So now I have blue, Pam's Perlemutter (double dwarf), tall perlemutter, and I will have the white. My blue ones are actually starting to seed.

So cool that it is so easy to grow one of my favorite plants!!!!!

Jackson, MO(Zone 6b)

I have to really stay on top of Platycodon as it re-seeds and spreads badly. It's a pretty color but man it wants to take over. Seedlings can be transplanted but I can't wait very long or they get too big and don't transplant well.

Elgin, IL(Zone 5a)

For the first time (better soil!) my blue ones are spreading. I think they don't do it in high ph soil and clay, which I used to have. They are very deeply taprooted and so have to be moved quickly. Baptisia is like that too.

I have noticed that I have two blue seedlings and I am going to transplant them. In many yards I have seen, the blue ones die out or don't spread at all. I found in my former yard that perlemutter was relatively fragile and died out - I have never been able to keep them for more than four or five years. The thing I notice most about the white is how quickly they germinate. I started 12 white ones eight days ago and have 8. I am going to tell my client that she should put them where they will not be disturbed over the winter. Before, my practice was to start them in January, get then into the ground by July and they would bloom in October.

Jackson, MO(Zone 6b)

Tap roots are white, and very brittle and when you try to move them, they break off.
I usually have very good luck starting seeds for fall planting. There's no worry about soil temperature!

Elgin, IL(Zone 5a)

Starting them in fall works? That's good to know.

I was starting to think that I was running out of room for new plants when I realized that I have a lot of plants that are place holders. I get lots of digitalis 'Husker Red' from the Prairie and Rain garden, where they don't care for them because they are the native type that has been pollinated, fragaria vesca reugen that I have grown and that a client had too many of, and geranium 'Bevan's Variety' that "puffs up" and I have so many that I give them to clients with impossible soil or who want no work (really builds good will). Feverfew too, because it reproduces itself easily. But I realize that I can now put other things there. I started taking out feverfew and geraniums and moving roses into those positions.

Now I am starting to better understand why my neighbors express shock about the lushness of my gardens. I have 50 or 60 of each of the plants I mentioned, not to mention about 20 heuchera 'Firefly' because I grow batches of them. None of those plants require any work or watering and look good well into the fall.

I had the coolest experience. I sang out a hello to a couple who were passing, and the woman said that she loved my "flowers". I asked which she meant, and she led me to verbena bonariensis. I love it. I grew about ten a couple of years back and this year at least 50 popped up. They are great at the front of beds, and if I have too many I just pull them out. And the hummer and butterflies love them.

It's really funny. People say that I must be a slave to my garden but I spend no more than an hour a day, often less. Having minimal grass really helps.

Jackson, MO(Zone 6b)

Donna, love your comments. You share such good information. I, like you, try to find flowers that are "no brainers". They let you enjoy the garden instead of constantly pampering it. This probably should have gone on a new thread because the information is so good. Enjoy your day and your gardens.

Elgin, IL(Zone 5a)

You are incredibly kind and generous to me. Thank you. I truly appreciate it!

Donna

Pequannock, NJ(Zone 6b)

Good advice! I have one of those floppy balloon flowers also so I'm looking forward to applying this next year. Actually, I'm not even sure I saw it this year.

Elgin, IL(Zone 5a)

It's not just you, Loretta. Sometimes balloon flowers just disappear, which is curious since the taproot is very deep. I find that the blue ones are almost bulletproof while the perlemutter is more likely to take a hike. The white ones do well. I started 12 very old seeds to get some for a client and now have 8 white ones in pots that are on their second set of leaves. I will need to do some more tall perlemutter since I thought I germinated that color and one of them is blue. I have TONS of blue.

Pequannock, NJ(Zone 6b)

Just second set of leaves. How do you think it will overwinter?

Elgin, IL(Zone 5a)

I have done this before. It's important to mark the location, and as I look at them, I see a third set of leaves. They look quite sturdy. All of them may not make it, but some of them will. That's why I start extras.

I don't plan to put them in the ground until the end of October. So they have almost four weeks to get tough. Then I put them outside for a few hours each day. Then into the ground.

Part of the fun of starting seeds yourself is that the cost of failure is close to free. And from experience I know that I can start them inside in January and they actually bloom in July.

I also have a bunch of polemonium carruleum. I love that plant. They have branched. I will wait until spring to seed the white polemonium. And thalictrum rochebrunianum. I am growing all the plants I loved at my former home.

Pequannock, NJ(Zone 6b)

Ok. I have a few small first year seedlings that I'm not sure will make it. Some pulsatilla and chelone glabra, all from collected seeds.

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