Archives

Catagories

Flower Seeds:

BhCR9-1

Cutting Back Various Perennials – What to Do and Why Do It in May?

It’s not difficult to have beautiful borders in May because almost every thing looks beautiful in April and May.

If you follow the way I garden, your borders have been mulched heavily after the April rains and you’ve already removed what few weeds worked their way in through the mulch that was left from the winter or crawled in from the properties that border yours.

Bloom is still sparse. The iberis and old fashioned primrose that started blooming in March are still blooming, but fading. Twice blooming iris made an appearance a couple of weeks ago. Various small trees like the virburnums and lilac have bloomed or are blooming.

The hostas have just recently sprung up and give great contrast and interest tucked among all the green.

Foliage of perennials like mums, giant rudbeckia, phlox, coreopsis, heliopsis, helianthus, asters, monarda, and solidago are at their best. And although their blooms will make a spectacular show at their designated times, the border is beautiful with just the foliage of these plants and a splash of what remains of early spring bloom here and there.

One of the Secrets to More Beautiful, Lush Late Summer and Fall Bloom

One of the secrets to keeping late summer and fall bloomers like mums (and the other perennials mentioned above) from getting too tall and scraggly looking is to cut them to the ground when they’re looking their best in May.

Many borders in the late summer and fall, never reach their full potential for bloom and beauty, because the gardener doesn’t cut these perennials back severely in the spring, which keeps growth shorter and more full in bloom time. It’s hard for some gardeners, to make the cut that needs to be made just when their plants are looking so good.

I’ve had folks comment on my mums many a year. And they always want to know what I do to keep them short, full, and covered with bloom. The answer is to cut them to the ground when they’re about a foot or more tall in May. And then cut them again by a few inches (or half) again in June.

Giant rudbeckia is another plant that is hard to work into the home border if it’s not cut to the ground at least once during the spring.  Otherwise, this plant can grow 10 feet or more.

Giant Rudbeckia in May.  About 2 1/2 to 3 feet tall.

Giant rudbeckia in May. About 2 1/2 to 3 feet tall.  The few stalks of phlox behind it are even taller.   The bramble is blackberry.  It works well for me to keep the blackberries in my front border.

Giant Rudbeckia cut to the ground.  I leave the cuttings where they fall.

Giant Rudbeckia cut to the ground. I leave the cuttings where they fall.

Giant Rudbeckia in full bloom in late summer.

Giant Rudbeckia 6 or 7 feet tall in full bloom in late summer after being cut to the ground in May.

What to Do

April and May (also known as Spring) are about fast growth.  You can cut back many perennials to the ground and within 3 weeks no one would guess that you ever cut them.

I Finished Cutting Mine Back A Few Days Ago

Here’s a list of the perennials (with a few additional notes) I cut to the ground in May:

  • Mums
Mums about 1 1/2 feet tall in May.

These mums about 1 1/2 feet tall in May.

Mums cut to the ground.

Mums cut to the ground with cuttings left where they fall.  They’ll dry up in a few days.

  • Giant rudbeckia (May’s cutting should do the job, but if rains are abundant and growth gets taller than I think it should, I’ll cut back by 1/3 again in late June.) Even with these severe cuttings it will attain a height of 4 to 6 feet.
  • Phlox
Phlox in May - about 2 feet tall.  Nows the time to cut it to the ground.

Phlox in May – about 2 feet tall. Now’s the time to cut it to the ground.

  • Coreopsis (This works with just about all varieties of coreopsis.)
  • Heliopsis
  • Helianthus
Helianthus in May.  I cut it to the ground several days after the picture was taken.

Helianthus in May. I cut it to the ground several days after the picture was taken.

  • Monarda (bee balm)
  • Asters (Once they grow to this height again, I thin out the thinnest stalks.  This allows for better air circulation as well as prettier bloom.)
Asters in May.  I cut to the ground in May and after they grow this much again I take out the thinnest stalks.

Asters in May. I cut to the ground in May and after they grow this much again I take out the thinnest stalks.

  • Solidago – I have the tall wild solidago in one spot of the back border.  It was already 3 feet tall when I cut it to the ground the other day.  This way, it’ll grow no more than 4 or 5 feet before it blooms.  If you want it even shorter cut it back again in June.
Wild solidago is top left; about 3 feet tall.  Giant Rudbeckia is to the right; about 3 feet tall.  Month of May.

Wild solidago is top left; about 3 feet tall. Giant rudbeckia is to the right; about 3 feet tall. Month of May. I cut both to the ground a few days after this picture was taken.

Different Approach to short cultivated Solidago (Goldenrod)

I have a lovely short solidago (Solidago sphacelata Golden Fleece). It adds tremendously to the fall borders, and will do so even if you don’t cut it.  This time of year the foliage at the bottom will be thick and it’ll send up stalks.  I just cut the stalks to foliage level causing it to branch more and give a bit more bloom in the fall.

A short variety of solidago in May.  Just cut the stalks to the foliage mass as shown by the circle.

A short variety of solidago in May. Just cut the stalks to the foliage mass as shown by the circle.

Make Your Last Cuts by the End of June

If you cut much after the end of June, the plant won’t have the time it needs to form bloom.

Leave the Cuttings Where They Fall

No need to bother removing the cuttings from these plants.  Leave them where they fall to feed the soil and thereby feed your plants.  The cut foliage will dry up within a few days and it won’t be long before you can’t even tell they were there.

Final Thoughts

As easy as this task is, many gardeners hesitate to do it.  If you want your late summer and fall borders to reach their full potential, get to cutting!  You’ll be glad you did when it’s time for those plants to bloom.

_______

All content including photos is copyright by TendingMyGarden.com

Be Sociable, Share!

4 comments to Cutting Back Various Perennials – What to Do and Why Do It in May?

  • Sandra

    Theresa, Thanks for the before and after pictures showing the cut. I’m one who finds it difficult and seeing the evidence helps!

  • sheila

    Thank you for the detailed advice here. I have read numerous suggestions for cutting back mums, etc. but have not had the best luck with that before. I was told to pinch back repeatedly until July 4th, and it was a lot of work for meager results. With your pictures, I can tell that it works to be more drastic and it also will save time, with I value! Thank you again for showing us the proof!

  • Theresa

    Thank you Sandra and Sheila for commenting.
    I try to show pictures whenever I can, but I don’t always have and won’t always be able to get pictures of the “proof.”

    It is unfortunate that almost every thing (and I’ve never seen an exception) you read on mums goes on about pinching back repeatedly until July 4th! I agree with Sheila, that is a LOT of work for meager results! I just can’t be bothered with that approach at all! Too much to do if I’m to accomplish everything I want to accomplish.(Not to mention that it doesn’t give good results anyway!) Having “another task” to constantly perform isn’t in my agenda.

    And yes, Sheila, doing it as I’ve instructed will save you TONS of times! I make the cutting back something I do each May as I walk around the borders on occasion to see what has to be done. I know it has to be done, but I don’t really make a job of it, but rather fit it in to something I’m doing anyway.

    Unfortunately, Sandra’s statement about ” I’m one who finds it difficult and seeing the evidence helps!” is probably applicable to many, many readers. But, as I said, it doesn’t always work for me to have every picture needed to show that evidence (proof), although I make every effort to try to get it for you.

    I am trying to provide information that is not readily available.

    I would say that the vast majority of gardening articles (and articles on any other subject too) are written by people who research and then write articles from what they have read.

    I just ran across a very young fellow recently that had written almost 300 articles for an article directory on 9 different subjects. One of the subjects was gardening. He doesn’t garden. You get the point. This happens all the time.

    And because there is so much “untruth” or “part truth” out there and because “if you repeat something often enough” people perceive it as truth whether it really is or not, it’s hard to tell who to believe and who not to believe, especially if the reader has no experience themselves.

    I DO have the hands on experience and I have enough of it, that even when I read other materials, I know enough to know if what I’m reading has validity or not.

    The bottom line to my “rant” (sorry, but it needed to be said) is that if readers have been reading my information and have gotten the excellent results from it (as I know many have), then hopefully readers would have a little faith that what I’m telling them is correct and will bring you good results whether I show pictures as proof or not.

    As I mentioned on page 8 in my book, Organic Gardening, Cutting Through the Hype to the 3 Keys to Successful Gardening, the main things I recommend for successful gardening (soil preparation, adding organic matter, and mulching) produce a combined effect much greater than the sum of the results of doing each separately. Then when you follow the other tips, it gets even better.

    I know and feel confident recommending various things to do because I’ve done it all many times and have seen the results in my own garden and borders.

    Let me know what happens in bloom time!
    Theresa

  • Theresa

    To everyone who may have already read this post prior to this note:
    I just edited the perennials list by removing daylilies and sedums.

    Sedum can be cut back.It won’t hurt them. I’ve done it many a time, but usually I don’t. If we have an extremely rainy season and they get too tall I cut them back several inches. I don’t really like to.

    Daylilies are only cut to the ground after the foliage gets shabby looking after bloom.

    My apologies to anyone who was a bit confused about this and thanks to Sandra for calling it to my attention so I could clarify.
    If you happen to have already cut your sedum and day lilies – don’t worry – they’ll
    come back and be just fine.
    Theresa

Leave a Reply

You can use these HTML tags

<a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>