Re: pruning question
- Subject: Re: pruning question
- From: John MacGregor j*@earthlink.net
- Date: Sun, 02 Feb 2003 12:23:34 -0800
on 2/1/03 9:29 AM, Barbara Sargent at rsgt@california.com wrote:
> I'm starting to prune my roses and, although I've been
> doing it for years, I have a recurring question about
> crossed branches: which one should be taken out if a new,
> thin one is crossing an old but vigorous one? This is the
> case especially with my Graham Thomas and Heritage.
Both 'Graham Thomas' and 'Heritage' are really big climbers. Both will grow
to 15-20 feet if given support and allowed to build up strength with light
pruning. I have managed to keep 'Heritage' to a 6-8-foot freestanding shrub
by shortening the vigorous new canes after they have produced their first
terminal bloom cluster. 'Graham Thomas is a monster, arching well above a
10-foot pergola. Both have long-lasting canes that will produce blossoms on
secondary wood for years.
The answer must be that you must make a decision on the relative importance
TO YOU of that old vigorous cane to that new one, and whether they are
actually touching each other. If the "old but vigorous one" is a key part
of the structure of the plant and is producing good secondary shoots, then
there is no question that your should leave it. If the new slimmer cane is
not actually rubbing against the older can, then shorten it to an eye
pointing away from the main cane a little below where you would like to have
a cluster of blooms. If they are not damaging each other, you can have
both. If there is too much congestion, you can always make onother decision
after the first bloom cycle, and remove one then.
There is a very simple equation that I follow when siting and pruning roses:
the more healthy canes a plant has = the more flowers it will produce. Thus
I plant roses far enough apart so that they can attain the size they
normally would like to grow with minimal pruning. Severe pruning cuts down
on both quantity and continuity of bloom.
> Also--I have an Iceburg which I've been pruning back to the
> first or second bud beyond the old wood.
When I prune 'Iceberg', I always try to leave four or five healthy eyes
beyond the previous cut--especially on the spring pruning. This gives me
one or two good sprays of bloom, and there are still two or three eyes left
to cut to if I want to limit its height after some later bloom cycle. In my
experience, the canes on 'Iceberg' are very long-lived, and after the plant
is 4-5 years old, it puts out very few new basal canes, but continues to
produce secondary and tertiary branches off the old, often very gnarly
branches. You probably will want to take out one or two of the oldest
branches that show lots of "dog legs" each year to stimulate new basal
canes.
> This rose puts out
> such long shoots that I'm wondering if it's a climber. How
> can I tell if it is? The branches don't arch the way other
> climbers do but it gets huge.
It is not unusual for a young, vigorously growing plant of the regular bush
form of 'Iceberg' to put out new basal canes 5-6 feet or more
tall--especially if the plant is growing in some shade. (We tend to plant
'Iceberg' in spots that get less than the ideal 6-8 hours of sun every day,
since it is quite resistant to mildew, and will often perform very well with
partial shade, but this makes it stretch out, looking for light). If the
new basal shoots produce a widely-branching candelabrum of bloom at the
apex, then it is certainly a bush form. The climber produces true climbing
canes, with blossoms only on side shoots--usually only in the second year
(although, with our extra-long growing season in southern California, I have
seen some blossom produced on secondary shoots in the fall of the first
year).
John MacGregor
South Pasadena, CA 91030
USDA zone 9 Sunset zones 21/23
