Tuesday, August 25, 2009

Divide & Conquer! by KCB

KCB is a professional gardener and friend who does wonderful work in the Greater Portland area. KCB is also an accredited Master Gardener by the Cooperative Extension Service and we are honored to have KCB as part of our Skillin's Garden Log family.

I tend to get a little melancholy at this time of year. As soon as the slight hint of autumn chill hits the air a rush of three distinct feelings or are they memories, overcome. First, I have a desire to go ‘back-to-school shopping’, though I have now been out of school for more years than I was ever in.

Second, I have the urge to sky dive. I have 11 ‘jumps under my belt’. The first 5 were a few days before starting my freshman year at The University of New Hampshire. My next six were the following September, at the start of my sophomore semester. To this day, I hear a small Cessna or Beechcraft type prop plane overhead; I secretly hope that I can transform myself back to a time when I had a little less sense and no real need for more.

Thirdly, it is at this time of year I am the most excited about the results of the gardening season yet my heart aches with the knowing that soon my pruning shears will be put into over drive as I cut back and clean-out.

So let us prepare to begin the end.

I’m not saying it’s is time to put our gardens to bed, let us at least wind it down, almost like drinking a cup of cocoa or warm milk to ease into the night.

For most perennials, fall is the best time to transplant and divide. Recently I facilitated a class and one common question ‘How do I know the plant needs to be divided?’

It’s not always as obvious as it would seem. If the plant is too crowded or too large, then division or transplanting is recommended. Many plants such as Achillea ‘Yarrow’, Gaillardia ‘blanketflower’ and asters, will become woody in the center. Others will simply form rings where nothing is growing in the middle, (Iris, Sedum). These are signs the plant has become too large and needs division. Hosta, Daylily, Shasta Daisy are served best to divide every 3-5 years. Others can remain undisturbed, Peony, Astilbe. Then there are those with such long taproots, Balloon Flower, or extensive root system, Baptisia, that generaly resent being divided or moved.

As in every gardening project we must prepare. A few carefully chosen tools will better serve than a random arsenal.

First thing to bring, a great attitude. We tend to be a little less enthusiastic at the end of the season. Think of it as getting a jump-start on next! Cleaning the closet to allow for more purchases. Mix and matching old favorites so everything is new again. Make a celebration of it. Put burgers on the grill, beer in the cooler and invite friends and neighbors. Their reward is a good time and a few plants. Next season can be someone else’s turn.


· Hand saw—sharp. I tend to make people nervous anytime they see me with a sharp instrument. Hosta and Daylilies are tough. Do not be afraid to dig right in.
· Digging Forks—2 would not be over-kill. Great for dividing daylilies. Simply position them back-to-back and push to separate.
· Sharp utility knife—perfect to divide bearded iris and peony.
· Hedging clippers or shears—Sharp! Great for getting many stems at one fell sweep. Hosta fear them, Daylilies are petrified.
· Flexible or 5 gallon buckets—magic number is 2; one half filled with water for any plants you may need to soak. This is great for untangling fibrous routes and removing invasive weeds or grasses from a perennial clump. The second bucket is to mix your soil and compost.
· Bagged planting mix or compost—I cannot say enough wonderful things about my favorite, Coast of Maine Penobscot blend. I always mix this in with the soil. I heard it once said, for a 5-dollar plant create a 50-dollar hole!
· Watering can—I water in before and after.
· Water Soluble Plant Starter—the reason for the aforementioned watering can.
· Gloves—I often have 2 pair, one designed for working in the mud. I get really down and dirty and since I have watered in before, there is no telling how dirty I can get.

The following is only a partial list of perennials. As always, our favorite gardening center is always happy to answer any specific questions you may have regarding dividing perennials. You do not even have to leave the comfort of your computer, just e-mail!

"What, When, Time, How"

Achillea ‘Yarrow’3 years
Early spring
Dig clump, shake off soil, remove central woody stem. Plant as dry root. Do not allow to dry before planting

‘Lady’s Mantle’
6-10 years
Early spring
Cut crown into sections making sure each crown has a strong root system

2-3 years
Early spring
Cut into soil with a sharp spade between mother plant and emerging growth. This plant benefits from early pinching.

Astilbe ‘False Spirea’4-5 years
Early spring
Cut plant into divisions with sharp spade or knife as new growth emerges. Each division should have 5-growth buds w/strong root support.

Baptisia ‘False Indigo’
Not recommended
As new growth emerges
Dig deeply around entire plant to expose extended root system, remove without breaking. Wash, clean and cut sections assuring that each section has several shoots and amply supply of roots.

Balloon Flower
Prefer not to be disturbed
Early Spring
Lift Clumps as new growth emerge. Dig Deeply so that as much of the fleshy root is taken. Wash plant free of soil and cut into sections making sure each has strong shoots and ample roots. May not bloom for a year or 2

Campanula ‘Bell Flower’
4-5 years
Early Spring
Cut into soil with sharp spade or knife. Make sure each crown has a healthy root system

Chelone ‘Turtlehead’Anytime
Early Spring
When new growth is 1 inch, sever the young plant from mother plant with spade.

BugbaneNot required
Early Spring
Dig clump, shake, and wash off soil, cut plant into sections containing several shoots and ample roots.

ClematisNot necessary
Early Spring
Dig entire clump when new growth emerges, cut crown into piece assuring each portion has 1-3 stems and generous roots

Coreopsis ‘Tickseed’
2-3 years
Early Spring
Dig entire clump as new growth emerges. Wash or shake the soil. Cut plant assuring each has several growth buds and ample roots.

Delphinium ‘Larkspur’
1-3 years
Early Spring
Dig entire plant as new growth emerges. Wash or shake soil, cut crown into sections assuring each has 3-5 stems and healthy roots.

Garden Mum
Dig entire clump; shake surplus dirt, cut off new growth from central core. Discard old portion and plant new sections immediately.

Hardy Mum
Cut clump into sections with sharp spade.

Dianthus ‘Pinks’
As needed
Early Spring
Dig entire plant as new growth emerges. Cut into sections making sure each has strong growth ‘eyes’ and healthy root system.

Dicentra ‘Bleeding Heart’
Every few years if needed
Early Spring
Dig up clump as new growth emerges, wash away all excess soil, and cut plant into sections. making sure each has strong growth ‘eyes’ and healthy root system.

Echinacea ‘purple coneflower’
If needed
With sharp knife or spade slice crown into sections.

Geranium ‘cranesbill’
6-10 years
Early Spring
Dig entire plant as new growth emerges, wash it free of soil, pull apart by hand. Assure each division has a number of strong eyes and healthy roots.

When clumps begin to die in center
Cut clump into section with sharp spade, discard old central portion of the crown

Every 3 years
Dig up entire clump. Use sharp knife, spade, or fork to divide. Wash soil. Make as many divisions as possible. Plant as bare root

Heuchera ‘Coral Bells’
2-3 years
Early Spring/l
Late Fall
Dig up entire plant, divide with sharp knife into sections of several stems and ample roots. Discard older center clump if woody.

3-5 years
Early Spring/fall
Dig up entire clump. Use sharp knife, spade, or fork to divide. Wash soil. Make as many divisions as possible. Plant as bare root

3-5 years or as needed
Anytime after blooming/late summer
Divide Rhizomes

Daisy ‘Shasta’1-3 years
Dig up plant, cut crown into sections with sharp spade or knife making sure each division has several shots and healthy roots.

Liatris ‘Gayfeather’4-5 years
As new growth emerges in spring or late fall. Dig up the plant and wash it free of soil. Cut the corms or rhizomes into sections with a sharp knife Make sure each division has strong shoots. It may be best to dust with a fungicide. Plant new divisions immediately.

As desired
Late Summer/fall
Dig up large clump, divide into individual bulbs, sow.

‘Gooseneck’, ‘Yellow’
6-10 years
Early Spring
As new growth appears dig entire plant, wash it free from soil, separate with fingers or sharp knife. Make sure each section has several shot and ample roots.

Monarda ‘Bee Balm’
Every year or as needed
Early spring
Dig up plant, cut into sections, remove woody or dead centers. Take divisions from the newest growth outside the clump.

Nepeta ‘catmint’As needed
Early Spring
Cut into clump as new growth emerges. Divide as needed making sure each section has healthy foliage and roots.

PeonyPrefer not to be disturbed
Early fall
Did deeply and remove entire clump from ground. Wash and clean dirt from extensive root system. Cut with sharp knife making sure each division has 3-5 ‘eyes’. Remove dried and broken root tissue. Recommend dipping roots in a broad-spectrum fungicide. Do not bury too deep to keep portion of ‘eye’ exposed.

2-4 years
Early Spring
Dig up plant as new growth starts. Cut Crown into sections each with 3-5 stems and ample roots. Discard central core if woody or dead.

‘Cone Flower’ ‘Goldsturm’
‘Black-eyed Susan
4 years
Early Spring/Fall
Dig entire clump retrieving as much as root system as possible. Cut clump into sections each with several stems and healthy roots attached.

Salvia ‘Sage’
As needed
Dig up the entire clump as new growth emerges or as plant dies back. Cut clump into sections each with several stems and healthy roots attached.

Sedum ‘stonecrop’
As needed to maintain shape and size
Early Spring
Dig up or slice into plant. Sedum has a tendency to fall away from soil as you work with the plant. May be planted in several clumps making sure healthy roots and shoots are attached.

2-3 years
Best as new growth emerges. Dig entire plant, use sharp knife or spade to cut into sections each with several stems and healthy roots attached.

Vernonica ‘Speedwell’
3-4 years
Early Spring/fall
Dig up or slice into plant as new growth emerges or as plant dies back. Cut clump into sections each with several stems and healthy roots attached.

It has been said that "all is fair in love and war". If it was only so in gardening. What we cannot conquer we will endure (or remove it complete and replace it with something better!)

KCB for Skillin's Greenhouses
August 28, 2008
(reprinted August 25, 2009)


Anonymous said...

Thank you. Very helpful!

Anonymous said...

Great information all in one place. I just went on the internet for propagation hydrangea and numerous other plants. I found lots of information...much of which is in your quick guide. I am forwarding it to some gardening friends.