NER DIVIDING PERENNIALS Clump forming and mat forming

MASTE
GARDER
DIVIDING PERENNIALS
Clump forming and mat forming perennials can be propagated by division. The advantage over
seeding is not just that you get bigger plants but that they are invariably the same as the parent
plant. Many perennial cultivars are hybrids which do not come true from seed. That can be
interesting, also, but it is slow and it doesn't help the garden which is a tangled mass of matted
and clumped, overgrown and ugly perennials.
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NER
Division works well for plants like Aconitum(Monkshood), Arabis, Aubretia, Delphinium,
Peonies (only every 5 years or so) Iris, Hemerocallis(Daylilies), Phlox (tall, medium and matted)
and all the hundreds of hardy perennials that deteriorate when the clumps and mats get too big.
Dividing plants will rejuvenate the plant, discard the central woody part, replant the
healthy perimeter pieces in a recently amended area of the garden. Ornamental grasses are
particularly likely to die in the centre of the clump, and therefore need dividing every 3 - 4
years. Heucheras become woody with age and again need fairly frequent division.
Divide them and either plant them, give them away, or pot them up (ordinary garden soil will do
for just a week or two) and bring them to the plant auction. Even if you think them invasive like
some artemesias, nepetas , convalaria and aegopodium bring them because somebody might have
the ideal huge area or contained niche where they will do well. Common perennials are the best
and cheapest form of instant landscaping if you have a local source (like the plant auction or the
family next door).
Most perennial herbs and rock plants can be propagated by division. A clump of chives can be
converted into a tufted hedge for a small knot garden. A patch of monarda with a dead centre
can be made into three small and healthy clumps. Daylilies filling a ditch can be dug out, divided
and made to stabilize a bank. Hostas can regain their youthful charm if they are reduced from a
tangled jungle to pleasantly isolated clumps.
Spring is the time of year to do this in Thunder Bay. Some books will recommend dividing
clumps in the fall but our winter comes too early and a whole summer to establish a new root
system makes a lot of sense even if you do have to do a bit more watering. Anyway, people have
more enthusiasm for change in the spring. Also bare patches can have a quick fill with annuals in
summer.
The important thing is to understand the plant. You need some shoot and some root on each
clump which means that you have to dig very deep for Peonies but you can divide arabis with a
good trowel or small fork. A knife, even a sharp spade or a saw will be needed for very old and
thick clumps.
If you want to remove a clump of perennials altogether remember that Delphiniums will come
back from bits of root left behind and so will Rudbeckia, Artemesias Dicentra and some oriental
poppies. The horrible thing about Lily of the Valley (convalaria) and Aegopodium (Goutweed)
and Mints of all kinds is that every bit that is left behind will be a new clump in a very short
time.
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LAYERING
This is a technique used more with shrubby plants eg euonymus, forsythia, clematis. The
basic idea is to weight, or peg down a stem or branch so that it is contact with the soil,
similar to a strawberry plant producing a new runner. The soil at point of contact should
always be kept moist ,it may help to enrich or replace it with a potting compost. Another
method would be to dig out the soil and replace it with a pot of compost, so that when the
new plant is eventually severed, it can be removed without disturbing the new roots. To
encourage new roots it is helpful to slice a very thin layer off the branch/stem at the point
of contact with the soil. Use a wire pin [cut pieces of a metal coat hanger] ,wooden peg or
heavy stone to keep the point of contact in the ground.
This is a slow method of increase and could take several years before the new plant could
be cut free.
AIR
LAYERING
FOR HOUSEPLANTS
Useful method for ficus, monsteras, dieffenbachias
dracaenas etc
This method often used for large plants that have outgrown their allotted space indoors,
or older plants that only have a bare ugly main stem with new vigorous growth only at
the top of the plant. If the objective is to propagate a new healthy plant from the parent one
select a site on the main stem where you want it to produce roots, remove some leaves if
necessary. Make a sleeve of clear plastic and fasten it around the main stem securing
the lower end with tape. Fold the sleeve down, and with a sharp knife cut a 'tongue' on
the stem with a slanting upward movement about 5mm [1/4in] deep and 2.5cm [lin] long.
Apply hormone rooting powder to the wound, and push moist sphagnum moss into the
incision using the back of the knife blade. Roll the sleeve back into position, and stuff it
with more moistened sphagnum moss, covering the area of the incision. When sleeve is
tightly packed secure the top to the stem with tape. When new roots are visible through
the sleeve,cut through the stem just below the root ball with sharp secateurs. Remove the
plastic sleeve, gently tease out the roots and pot into an appropriate container that allows
5cm [2in] of space around the root ball. Water, label, place in a shaded position and water
sparingly until the young plant is established.
Note it may be many months before roots start to develop. If moss dries out, open up the
sleeve and add some water then reseal.
STEM CUTTINGS
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Nothing difficult about this, what you are attempting to do is remove a shoot from the
plant and persuade it to put out roots. Most plants that will root seem happiest to send out
shoots around the node. Choose cuttings from good sound plants which should be vigorous
and disease free.
Good examples of these would be delphiniums and dahlias, when new stems are about 1015cm [4-6in] in the spring. Other plants such a penstemons, artemesias ,sal vias etc can
have cuttings taken from some of the lateral side shoots. Then plant out in a nursery bed
where they can be watered ,fed, and monitored until planted in a permanent position in
the garden.
In late Septmber before a killing frost, taking cuttings from tender perennials used as
container plants in the summer can be taken and kept under fluorescent lights for the winter.
Cuttings need to be taken with a clean sharp knife and placed in a plastic bag, sealed and
placed in a cool dark place until ready to be prepared.. If they go limp before being
prepared can be revived by standing in water. A sterile blade is best used for the final cut
when preparing the cutting, immediately below a node. Overall length of cutting should
rarely exceed 7.5cm [3in] in length. Remove all lower leaves cleanly with a knife leaving
no snags of pieces of stem, otherwise rot may set in. Cutting the size of top leaves may
help too . Leaving too many leaves are more than the non-rooted stem can cope with,
and it will wilt
Dip the end of the cutting into a hormone rooting powder or liquid, and shake to remove
excess.. Make a hole in the cutting mix 50:50 pro mix with perlite works well, with a dibber
and place the cutting in the hole so the its base is in contact with the cutting medium,
firm around the edge so there are no air gaps. If putting several cuttings into one pot,
insert them around the edge. For some reason this seems to promote a quicker and more
vigorous root system.. Cover the pot loosely with a plastic bag to promote humidity.
Remove when signs of growth are apparent. As the cuttings get bigger and roots appear
from the base of the pot, repot into individual containers. Make sure the pot is not too
large, the new roots will quickly rot if surrounded by too big a volume of damp growing
rmx.
Keep them growing on, pinching top growth where necessary to make a compact bushy
plant, and feeding etc. By the time spring comes plants are big enough to have more
cuttings taken from them should you require additional plants.