Wednesday, February 19, 2014

Time to Crown Your Roses

 Me and Betty Boop, November 2013.  Notice the lilac in the background, losing its leaves.

           Spring has sprung midwinter this year, but you can expect that kind of thing in Grants Pass, where our spring is “indeterminate.”  It comes and goes anytime from February to May, when it slips in and out of summer for a couple months.  An extra-cold December gave way to a warm January, and shifted winter and spring two weeks to a month early.
This year, spring started by the end of January, when my roses started breaking bud.  I’ve been crowning roses for three weeks.  Having crowned most of these roses last spring, the work went pretty quickly, even where they grew full-sized canes.  I didn’t have to dig much.

Betty Boop, crowned.  It's seven inches across, and the original trunk was 3" at the base.  This year's canes were all 1 inch or less wide.

To “crown” a rose is to cut it to the crown, the hard knot of wood above the roots, rather than cutting it off knee-high.  This removes all black spot fungus on the plant, which infects canes as well as leaves.  It also looks more natural and thus beautiful than growing from cut canes, which produce beautiful flowers on an ugly bush, breaking out in black spot (yellow spots that turn black and eventually kill the leaf) on the new growth before the flowers even bloom.  Crowning roses in spring can keep black spot at bay until late fall, if it shows up at all.

Betty Boop, November 2013.  Notice the black spot beginning to show beneath. 

Black spot is endemic in Grants Pass because there are so many roses and our mild wet winters never make them go fully dormant.  The leaves and stems grow the fungus all year.  Outside of town, it is possible to eliminate it with hygiene; in town, it is in the air everywhere.
I used to cut rose canes to the ground or the crown, whichever was higher.  But underground cane bases produce small, spindly growth.  It pays to dig down around the crown and cut every cane to the hard ball of the crown.  It is easier when it was done the year before.
A rose can be crowned at any time during the year; it’s hard to kill one by cutting it.  Crowning when it’s half-way to blooming is apt to shrink the plant, which is good when the rose wants to be 6 feet tall and you would prefer 3.  Cutting in late fall to mid-winter may delay regrowth in the spring by several months, as the plant feels only soil temps, which lag far behind air temperatures.

Betty Boop, February 18, 2014, ready to be crowned.  Note the red new growth sprouting all over, and yellow black spot on only the oldest leaves.

I am most happy with my Betty Boop rose in my front yard, a semi-double which, after crowning last spring, was covered with blooms all summer and fall right up to our December deep freeze, which froze all the buds on every rose in town.  Even now, it had very little black spot, but it was time to crown it for the third time.  It was huge at one time, as you can see by the stump, but ugly with black spot.  Now it’s consistently pretty and compact.
Not every rose should be completely crowned every year, only regular tea roses.  Climbers grow their flowers on two-year-old wood, so only the bloomed-out canes should be cut out, and the new canes be allowed to bloom.  Rosa rugosa has heavily textured leaves that don’t get black spot, and should be crowned only when it gets too big for its space.