The old folksong, Wild Mountain Thyme has in
the chorus “We will all go together to pull wild mountain thyme.”
We wince at that line because pulling the thyme will kill it. The
Herbin’ League trio (a group of old-time folk musicians hailing
from the Ozark Folk Center in Mountain View, Arkansas) changed the
lyric to “…cut wild mountain thyme.” But some herb gardeners are
afraid to do even a small amount of judicious pruning, often out of
a fear that the plant will be harmed. Education is the key: Once we
understand how plants function and the reasons for pruning, it is
easier to sharpen the tools and get to work.
We harvest herbs during the growing season just as the flower
buds are formed because the plant oils are at their peak.
Deadheading flowers improves the look of ornamental plants and
often extends the bloom time. If we are preserving annual and
biennial herbs such as basil, chervil, cilantro, dill and parsley,
we cut them before the plants flower. Whether pruning for harvest
or plant health, we prune before autumn so new growth has time to
harden off before a hard freeze.
Herbs need pruning for purposes other than human consumption, so
don’t feel guilty. Diseases and pests are controlled with proper
pruning techniques. We need to prune to control rampant growth or
shape plants in a formal or stylized garden. Heavy pruning is best
done in winter for deciduous plants and spring for evergreen
plants. Avoid pruning herbs when new leaves are budding in spring
or old leaves are falling off in autumn. It is best not to prune
during times of drought.
Root pruning is performed on plants to increase health and vigor
or to transplant from one location to another. We don’t do this all
of the time or with all of our plants, but only when the plants
need it. Overall, plant growth is always more vigorous in the
spring, but roots of perennial plants are active year round.
Pruning the roots when the soil is warm and deeply moist is the
ideal condition for new root growth — not too cold nor too hot, and
moist enough to sprout but not dry out. The idea of root pruning is
to encourage the feeder roots to grow.
Visualize plant physiology
Plants have a vascular system, like human blood vessels, that
transports water, minerals, sugar, growth-regulating hormones and
nutrients throughout the plant, supporting its life. Like our
vascular system, fluids move in two directions through different
sets of tubes and pipes. These tubes and pipes are bundled together
just under the skin (dermal tissue) of the roots and stems.
Working upward from the earth, tiny root hairs absorb water and
minerals from the growing medium. This fluid moves through the
vascular system into larger roots, the crown, into the main stem,
the branches and out into the leaves. When roots are pruned, new
feeder roots grow from the remaining parent.
Above ground, the leaves of plants are chemical factories. With
the help of sunlight, plants feed themselves and the world by means
of photosynthesis. Leaves contain the green pigment chlorophyll,
which produces sugar in the presence of light, carbon dioxide,
water and dissolved minerals. The chemicals travel through another
set of vascular tubes and are carried to every living tissue
throughout the plant to enable growth and reproduction. We harvest
herb leaves for desirable flavors and beneficial chemicals. When
harvesting your herbs, follow the “take a third” rule and leave the
rest for the plant.
Plant stems grow either from the root straight up from a crown,
along the ground or below the surface of the growing medium. They
support the leaves and hold them up to the light. Stems can produce
roots and reproduce new plants. Leaves, twigs, knots or buds along
the stem are nodes. The vascular system, just under the dermis,
stretches from node to node. Stem skin is made of waxy material or
dead cork cells that protect the living wood and vascular system
from heat, fire, cold, insects and disease. Use sharp tools and
make clean cuts in the right places to avoid tearing the dermal
To prune properly, cut above a node. A node is the place where
leaves or stems occur, which can be seen as a line, knot, bud, or
collar and crotch. Potential for new growth takes place at the
node, as does the fastest healing of the pruning wound. Cuts made
between nodes leave a nub that has to die back to a node as it
heals. This is unattractive and can allow disease to enter the
vascular system of the plant.
When we cut a branch just above the collar that joins it to its
parent branch, we are redirecting energy in the form of water,
nutrients and hormones to the remaining branch. When we cut stem
tips above a node, we are redirecting this energy to the nodes
below the cut.
Leaves, stems and roots that lack a healthy color are no longer
functioning as a part of the feeding system. These parts should be
Prune roots when transplanting
Plants kept in pots that are too small to support the nutrient
and water requirements become root-bound. To check for this, gently
turn the plant out of its pot. New roots should be white, in most
cases. The small roots should have hairs, which absorb water and
nutrients. Captive roots displace the growing medium in search of
food and water, and they twist to conform to the pot. Eventually
the roots can girdle the plant and suicide ensues. Herbs in
containers appreciate transplanting as needed when they are
Mature plants need annual root pruning for optimum health and
growth. When pruning roots, use a sharp, clean knife or a pruner.
Take care to maintain the integrity of the root ball by pruning
away only the outer surface of the ball. Cut away dead, diseased or
winding roots. Pot the root ball back into the original container
with fresh growing medium, or move it into a larger pot.
It is handy to use containers as halfway houses for bare-root
plants or plants you want to transplant from one place to another
in the garden. First, prune the roots, pot the plant and set it in
a protective place for extra nurturing to encourage new feeder
roots to develop into a contained root ball. After two or three
weeks in the pot, the plant will make a much easier transition to
its new home.
Prune for health
Herbs need good air circulation and sunlight to dry moisture
from the leaves and soil surface. Fungal organisms thrive on damp,
dead tissue. Prune away some branches that are growing along the
surface of the ground, as in the lateral branches of lavender and
sage. Pruned in a balanced manner, the plant will retain a natural
appearance while allowing air to pass around the remaining
branches. Proper pruning techniques help reduce disease. Prune away
diseased plant parts. Disinfect pruning shears with alcohol between
each cut. Prune right above the node or crotch of a branch or twig.
Sharp pruners will completely sever the branch without tearing away
sections of protective bark. This will insure speedy healing of the
Sharpening bypass pruners
We find our pruners to be an essential garden tool, and we favor
bypass pruners, which are sharpened only on the outer edge, to the
anvil type, which is sharpened on both sides of the blade. Bypass
pruners give a close, even cut as the blade slides past a hook with
a sharp edge. If the pruners are sharp, this results in a clean cut
that does not crush stems. Anvil pruners have a sharp blade that is
sharpened on both edges that meet a flat surface. This action often
leaves a bit of a stub. Pruners come in all sizes and many
different shapes designed to suit the various needs of the
gardener. Try them out for size by holding them in your hand, or
borrow a friend’s and see how they work for you. Look for blades
made of tempered carbon steel so that they can be sharpened
Three sharpening essentials
Although there are many sharpening gadgets on the market these
days, we prefer a round-edge water slipstone, also called a
Japanese slipstone or a tapered whetstone, to sharpen our pruners.
These slipstones are shaped to get both flat and curved surfaces
all the way down to the edge. These stones are a handy size, as
they fit comfortably in the hand, a pocket and other small places.
Usually of a medium fine grit, these stones are inexpensive and
last virtually forever. They are versatile and can be used to
sharpen many kinds of blades, from pocketknives to scissors.
Alcohol is used throughout the sharpening process. This solvent
cuts through plant sap and grime and kills microbes on the pruner
blades. Unlike water, it evaporates quickly, reducing the formation
of rust. Unlike oil, it will not leave a residue on plant material.
Alcohol dries clean. It also washes away metal filings from the
pores of the sharpening stone. The grit of the stone is what
sharpens the metal blades. If the grit is clogged with grime and
metal filings, the stone itself becomes dull. Therefore, always
wash the stone before and after the sharpening process. You’ll need
a sturdy and absorbent clean cloth, which will readily soak up
alcohol and can be used to wipe the blade.
When sharpening your bypass pruners, it is good to remember that
the cutting edge is the one that does the actual cutting by
severing the tissues, while the blunt edge holds the plant material
but does not actually cut. One of the most common mistakes is to
think of the cutting blade as a double-edged tool. Do not turn it
over and sharpen the other edge; maintain the factory-made edges
Prune away pests
Aphids and mealy bugs often congregate on the young, tender tips
of plants. Pruning these tips removes the pests and stimulates
growth from the nodes below the point of the cut. This produces a
Regenerate mature perennial herbs
A combination of top and root pruning will stimulate new growth
and keep plants happy in the spot they are planted. If you are
consistent with annual pruning over the years, the plants should
remain bushy and healthy for a very long time. These herbs grow the
way they do because they spread in search of nutrients and water by
rooting along lower branches. As the original plant exhausts the
soil resources in its root zone, younger branches take root and
Thyme, sage, rosemary, lavender and winter savory can take on a
“poodle cut” appearance as they grow older. “Poodling” is a term
our gardening friend, Deborah Redden, uses for this look, which we
find perfectly describes new bushy growth on the end of old, bare,
woody stems. The wood in the center of the plants weakens because
the load is out on the ends. To avoid this problem, it is important
to prune the plants at least twice in a growing season, in the
spring and mid-summer. First and always, prune away dead and
diseased parts. Then, prune to improve air and light circulation.
Finally, take up to a third of the youngest growth at the top of
the stems. The goal is to encourage new growth from lower sections
of the branches and the crown of the plant.
To prune the roots of a mature plant, sink a sharp spade in a
circle around the root ball. Do not tilt the spade. Just sink it
straight down and bring it straight out again. This will sever
roots without disturbing the root ball. New feeder roots will grow
from the pruned root ball. Follow up with a drenching of liquid
fertilizer, concentrating the solution into the root zone. We use
liquid or granular kelp, fish emulsion — often a combination of the
two for a more balanced fertilizer — or compost or manure nutrient
teas to feed our herbs.
Enlightened pruning practices, as well as a better understanding
of plant physiology, will give you the confidence and awareness you
need to prune your herbs for bountiful harvest, health and
Susan Belsinger is long-time contributor to The Herb Companion,
but this is the first time she and her herbal cohort Tina Marie
Wilcox have published together here. Susan writes, cooks and
gardens from her home garden in Maryland, and Tina Marie enjoys
gardening in the Heritage Herb Garden at the Ozark Folk Center in
Arkansas. The two currently are contributing to an upcoming book by
the Brooklyn Botanic Garden on theme herb gardens.
Pick a pruner-any pruner
Now that you have the lowdown on pruning, you
may wonder how to choose from the many pruners available in your
local home and garden store. Pruners come in all shapes and sizes,
varying in cutting power, durability, appearance, comfort, cost and
more. Since personal preferences also vary, pruners mean different
things to different people. Taking these factors into account, we
sampled some pruners, weighing their strengths and weaknesses.
Perhaps you’ll find some here that work great for you, or maybe our
comments will help you evaluate pruners before you buy. If you
already have a favorite set of pruners not listed here, let us know
so we can share with other readers. Send your suggestions to:
email@example.com or write to “In Basket,” The Herb
Companion, 1503 SW 42nd St., Topeka, KS 66609.
* Ratings are from 1 (very poor) to 5 (excellent)
Fiskars Power-Lever® Bypass Pruner (Model
Fiskars Garden Tools
780 Carolina St.
Sauk City, WI 53583
With a surprising power-to-size ratio, this pruner proves
effective for small cuts. The hinge makes for easy pruning, while
the small, pocket-size design makes for easy carrying.
Retail Price: $20
Power: This mighty pruner multiplies cutting power 35
percent by combining more power with less effort and less hand
stress. Its sleek design enables precision cutting in dense growth.
Cuts up to 3/4-inch diameter branches.
Durability: The steel blades are fully hardened
to withstand years of cutting duties.
Comfort: Although comfortable for small to
medium hands, this pruner may squeeze or pinch larger fingers. The
lever is built into composite handles, so when the handles are
squeezed together, the bottom handle remains parallel to the top
handle, minimizing friction, strain and fatigue. The lock operates
with a simple touch, protecting blades and preventing
Fiskars PowerGear® Bypass Pruner (Model 7936)
For cutting through the big stuff, this is the pruner for you.
This easy-to-use pruner snaps right through large roots and stems.
We especially like how the handle rotates when you squeeze, which
not only feels comfortable, but doubles your pruning power.
Retail Price: $30
Power: This extremely tough pruner can cut up to 3/4-inch
diameter branches and provides more power with less hand stress.
The bypass design is great for cutting green and growing wood. The
parallel handle opening allows you to use all of your fingers when
the handles are squeezed, providing for optimal hand strength.
Durability: Precision-ground steel blades are
fully hardened to stand years of cutting duties, and the Xylan
blade coating reduces friction and rust.
Comfort: As with the other Fiskars, the gear on
this pruner is built into composite handles, so when you squeeze
the handles together, the bottom handle remains parallel to the top
handle, which minimizes friction, strain and fatigue. Best of all,
the Fiskars 7936 has an adjustable handle opening to alter the
“throw” of the opening, making it smaller for small hands or larger
for big hands.
Florian Ratchet-Cut® Pruner (Model 701)
157 Water St.
Southington, CT 06489
Although they were somewhat effective, we found that these
pruners didn’t work as well as either of the Fiskars or the
Gardena. In one instance, it took two cuts to get through a small
thistle stem. We like the sharp point on the blade, and the
straight edge is good for some cuts. The ratchet comes loose
easily, which creates an annoying clickety sound, and overall this
pruner appears to be cheaply constructed.
Retail Price: $31 ($36.95 with holster)
Power: This patented Ratchet-Cut mechanism is supposed to
multiply your strength by 700 percent, but we didn’t find it that
strong. Cuts up to 3/4-inch diameter branches and is ideal for
precision cutting of flowers.
Durability: This pruner seems to be cheaply
made, but if taken care of, it should last long enough. The handles
are fiberglass-reinforced nylon, and the high carbon steel blades
are Teflon coated to resist residue buildup.
Comfort: This pruner was the lightest of the
bunch, which can be handy for lugging around. The shape and size of
the handles feel comfortable in most hands.
Gardena Adjustable-Grip Bypass Pruner (Model
3085 Shawnee Dr.
P.O. Box 2840
Winchester, VA 22604
Accommodating to various hand sizes, this pruner makes for easy
cutting no matter what your size and strength. Although effective,
some people may find the safety lock difficult to use.
Retail Price: $25
Power: Best for cutting flowers, shoots and live
branches, this pruner cuts up to 7/8-inch in diameter.
Durability: The aluminum construction includes
a hardened steel blade that stays sharper longer and has a rust
resistant coating for cleaner cuts. The rustproof spring works well
but could cause problems later on if you don’t take care of it.
Comfort: The handles adjust to any hand size
for maximum comfort, and the integrated rubber buffer is gentle on
Triman Bypass Pruner (Model 2015)
Triman International, Inc.
140 Kipp Ave., Bldg. #20H
Elmwood Park, NJ 07407
As the most affordable pruner we reviewed, we felt the Triman
was quite comfortable and powerful, yet not as durable as the
Retail Price: $5 to $8
Power: The high carbon steel polished blades make this a
tough pruner for its size, but the coil rebound tends to restrict
Durability: If not taken proper care of, dust
or dirt may weaken this pruner quickly.
Comfort: The aluminum alloy handle with PVC
coated grip makes for a nice, comfortable grip, which conforms well
to your hand.
Do you have a favorite tool you’d like us to test? Send your
ideas to: firstname.lastname@example.org or write “Product Tests,” The
Herb Companion, 1503 SW 42nd St., Topeka, KS 66609.