Return to Rosy Tips
by Monica Valentovic - Consulting Rosarian - Huntington Rose Society
In a few weeks it will be time to begin Spring pruning of
the roses. The weather has been quite variable so far, but new growth is starting to develop within the garden. Although this
winter was fairly mild, the Spring has been slow to generate much warmth of the soil. However, April and May is the time to
get rosebushes ready for another season of growth and beautiful blooms. In fact, 7 weeks from the Huntington Rose Show is
all Roses Pruned the Same Way? - Hybrid teas, grandifloras, and floribundas are essentially pruned in the same manner. This technique requires individual
cuts to be made to remove unwanted weak growth, small forks in main canes, suckers, and dead or damaged cane material.
Why Prune Roses in Spring? We prune roses in the Spring for several reasons. First, roses are pruned to remove dead or damaged canes. Dead or
severally damaged canes can act as a reservoir for diseases and insects that can further damage the healthy portion of the
plant. Dead canes also need to be removed to allow more air circulation and to provide room for new basal shoots. Secondly, roses need to be pruned to remove any growth that is weak. Weak canes will not promote vigorous
or healthy growth, and the production of blooms will be reduced on weak canes. For example, if a rose bush has 3 canes that
are 1/2" in diameter or larger and one cane that is less than 1/4" in diameter, the smallest cane should be pruned. Third,
for most roses pruning helps to shape the plant to promote air flow through the center of the bush. By maintaining a good
air flow, the occurrence of diseases such as blackspot can be reduced. And lastly, pruning stimulates the growth of new canes
and helps to stimulate the regeneration of the bush. It is difficult to decide which canes to prune, but remember, that you
are setting the tone for the number of canes that will begin growth for your plant with this Spring pruning. Also remember
that you do no justice to your plant to prune conservatively. If you prune a cane before white pith is present, you will have
a weaker shoot that will die in June or July. So prune carefully but thoroughly.
Figure previously published
in The Rose Reporter January 2001 by Dr. Tommy Cairns, entitled "The Art and Technique of Rose Pruning"
Cuts should be made until white pith is revealed within the cane. For proper cutting of a cane, make your cut at a 45 degree angle approximately 1/4"
above an outwardly facing bud eye. This distance allows the bud eye to develop properly and produce a cane that will grow
away from the center of the bush (for maximum air flow). The cut on the bud eye side of the cane should also be higher than
the cut to the inside of the cane. The cut is made at a 45o angle in order to reduce accumulation of water at the site
that will promote disease growth.
Figure previously published in The Rose Reporter January
2001 by Dr. Tommy Cairns, entitled "The Art and Technique of Rose Pruning"
After the pruning cut is made, cover the
cut with some type of sealing material to prevent sawflies or carpenter bees
from boring into the cane and laying eggs. The larva produced from these insect eggs are called cane borers, and they will
eat the pith of the cane and cause severe damage to the cane. There are many types of sealing compounds that can be used to
block the insects from laying eggs in the open pruning cut in the cane, including orange shellac, carpenter's glue, and tree
pruning sealant (that black tarry stuff that gets all over everything!). Our favorite cane sealant is a product called
at some local nurseries and through the
magazine. This sealant is a green waxy material that can be rubbed over the end of the cane to seal it,
but it is best applied with a Popsicle (or craft) stick or other small flat
object. The material soon dries to a hard seal that will not wash off in the rain and will last over a year or more.
Miniature roses can be pruned the same way as hybrid teas
or floribundas, but many folks are happy to take a pair of hedge trimmers (manual or electric) and lop off the minis about
12" high or so (depends on the growth habits of the rose and winter damage). Then, they just let them grow. If you use this
approach, make sure that you still remove the dead wood and twiggy growth for the reasons mentioned above. Gary prefers to
trim the canes of the minis individually, but it does take a lot longer, and the "mass trimming" approach is easier on the
Pruning climbers and shrub roses is usually done to remove
only dead and damaged wood in the spring. It is best to know your climber prior to pruning. Some climbers bloom only on second
year growth. Others only bloom on lateral shoots from the main cane. Consequently, trimming the canes may reduce the amount
of bloom the bush will generate next year. Canes older than four or five years old should be removed to stimulate the production
of more basal breaks and help with vigor. Once-blooming climbers should be pruned after the initial bloom cycle is complete.
Established canes can then be cut back to where they are about a pencil width in diameter. This will allow new growth to develop
between June and October. Side stems that have bloomed can be cut to the lowest five-leaflet stem, which should be about 1
to 2 inches from the main cane. This pruning process will aid in promoting bloom along the entire length of cane.
Old garden roses should not be pruned as if they were hybrid
teas. Remove dead or damaged canes and prune lightly. Last years canes should be pruned to promote bloom production, and a
few of the older canes on an established bush should be pruned back to stimulate new cane formation. Severe pruning of an
old garden rose can do more harm than good.
After the roses have been pruned and the ends of the cut
canes sealed, the pruned canes should be discarded. The roses and ground should then be sprayed with a fungicide to prevent
any fungal spores from getting established in the garden. You can use lime sulfur or copper but you must use a growing dose
since many leaves are developing on the rosebushes.
When the pruning is finished, we usually add Mills Magic
Mix, Rosetone or Alfalfa Meal to the soil around the base of the bushes to provide an organic fertilizer for the roses.
As the soil warms above 55oF, the microorganisms
in the soil will begin to break down the organics to help feed the roses.