Right
now is prime time to crown your roses.
To get rid of black spot for the summer and make them grow their best,
they must be cut to the crown, the solid knotty base below the stems and above
the roots, and allowed to grow fresh canes.
A Betty Boop rose, crowned mid-summer and blooming heavily in September
Cutting them off a foot high, the conventional way
to treat roses in mid winter or early spring, leaves black spots on the stems
and keeps the infection going. The same
goes for taking the old leaves off as the new leaves start to grow in; the new
growth will be spotty before the new roses bloom.
This applies mainly to tea roses that are not
climbers. Climbers bloom on second-year
wood, and you will lose a year of bloom, but you can cut individual canes after
they bloom. Rosa rugosa doesn’t get black spot or molds, but should be crowned
and allowed to regrow when it gets too large.
Josephine County, with its mild, wet winters and
cool, rainy springs, is a hot-bed for black spot and other fungal
diseases. In Grants Pass, with many
roses neglected entirely, photinias spreading the same diseases, and a
city-owned pear orchard that was neglected for years and is in the process of
being cleared, they are epidemic.
One can crown a rose anytime, and I have been doing
so as soon as I saw black spot or mold for the last few years. I have even crowned them in late fall and
midwinter, but that slows re-growth in spring, as the plants get no warmth from
the air and must wait another month or two for the soil to warm. So this year, I crowned them after they broke
dormancy and started to grow in early spring, which comes earlier here than
most places at this latitude, in mid-February.
Some are already re-growing, only two weeks later.
Joan's rose, about two months after a February crowning
Cutting to the crown means cutting each cane to its
base. Roses hate any kind of dead wood,
which blocks new sprouts, and branches that grow from stubs do not grow as well
as a cane from the crown.
Crowning roses sometimes means going underground,
when they are planted too deep or sink into rotting organic matter, like a
stump. The latter happened to one of my
dad’s roses, which I had been cutting only to the ground for several years; it
kept growing back smaller and more spindly from such treatment, as its stems
were growing from underground stubs, not the crown.
This year, I was determined to cut all roses to the crown,
and dug to find it. The top of the crown
was a good 8 inches below ground, and it went a foot deeper, with thick “arms”
reaching for the surface as the years went by, and roots reaching up around it. Not wanting to dig that far every year, I dug
it out and planted it with the crown above ground. It should live; roses are tough. (It didn't. That's all right; roses are cheap.)
You can’t hurt a rose by cutting it, just by not
cutting it sufficiently. Go all the way
to the crown for best re-growth and to beat the black spot. Do it as the new leaves grow in early spring,
and you can have clean, pretty roses all summer. If you don’t, you can do it again as soon as
black spot or mildew shows up. The tea rose
is a royal pain; it needs to be crowned.
Rycke
Brown, Natural Gardener 541-955-9040 rycke@gardener.com
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