Wednesday, June 20, 2012

Rose problems at the Gardens

Earlier this month my master gardener group had a tour of the Centennial Rose Garden at the Royal Botanical Gardens in  Hamilton. The reason behind our visit was to learn about the changes the gardens have made or had to make since the Ontario pesticide ban in 2009. Through consultation with other large gardens they have returned to 'heritage' care techniques, or in other words, organic practices. Not surprisingly, this is not as easy a feat to accomplish with gardens of its size and unfortunately a lack of funds to support their endeavors in order to present the gardens at the level of quality for a botanic garden.

Climber 'Alchymist'
 The main problem they deal with in the rose garden is black spot. Anyone who grows roses knows this problem well. How do you create beautiful beds of let's say hybrid teas when all their bottom leaves are turning yellow and falling off? Not a pretty sight. Keeping the beds clean looking is presently more of a priority than the actual prevention of the problem especially during rose season. 

Climber 'Roberta Bondar'

The problem of black spot is the result of the way they prepared the beds for the winter. Each rose bed was covered with a plastic sheet of polyfoam and then trenched in. Even the climbing roses received the same practice being removed from their supports, laid on the ground and covered in polyfoam. Black spot, weeds and mice thrived under the plastic and after years of following this practice the soil is completely infected with the fungus. To add to this, most rose beds are grown just as that, rose beds. This creates a monoculture in which pests and diseases thrive.

Parkdirektor Riggers

In the last few years there have been changes including planting roses that are hardier for our zone, growing more shrub roses like rugosas which are relatively trouble free, and growing more disease resistant varieties such as the 'Knockout ' roses. They are also playing with some new mixed plantings such as roses, clematis and grasses.

Captain Samuel Holland

There is still a lot of work required to bring the Centennial Rose Garden up to the level it should be and one day they will achieve that. For now they are looking at ways to replace all the soil in each bed, a  huge goal and very costly endeavor. In the meantime the rose gardens are still a lovely place to wander through with camera in hand and nose at the ready.

Bed of species roses

rosa foetida bicolour 'Austrian Copper'

rosa foetida 'Persian Yellow Rose'

William Baffin

roses galore!

Knockout roses with clematis and panicum 'Heavy Metal'

Knockout 'Carefree Celebration'

gorgeous Knockout - sorry never got the name



  1. Roses and our climate just never seem to jell. Some years they remain pretty disease free, and others the blackspot and Japanese Beetles decimate them. The only roses that I plant on client's properties are Shrub, Iceberg and Knockouts to lessen chemical use. They seem to be less negatively affected. I was just across the border to the rose beds in Canada, and they are looking pretty good so far this year. I will get to posting them soon. I am glad to hear that the Centennial Rose Garden is making changes. It is a lot of work to care for fussy roses.

    1. My problem is that I love the smelly roses and they tend to be some of the antique varieties which are not as resistant as of course the less to non-smelly hybrids and cultivars. Knockouts are starting to look better and better.

  2. Hi Patty (thanks for stopping by my blog girl !) .. yup ! getting inventive with keeping our roses clean and healthy is a job in itself .. I have been using the Epsom Salts dose once a month until August and I do think it strengthens the vitality of the roses .. from shrub, tea, to climber .. but now with this heat and humidity beating down on us .. I expect to have more problems of the HOLY YUCK ! kind soon!
    Joy : )

    1. I know what you mean. Aphids and Japanese beetles are my pests, not black spot. I have never tried Epsom salts , maybe I should think about. Try and keep cool Joy!

  3. Coming form the tropics, I have this notion that roses grow very well in the cooler regions of the world.
    I did not know so much trouble needs to be taken to get those lovely blooms and lush leaves.

    I will visit often , to get more ideas about how to grow them.

    Thanks for sharing.

    1. Thanks for visiting! You may not be able to grow roses in Hyerabad but you have many other beautiful plants I wish I could grow here.

  4. Gorgeous photos. Nice to know the professionals are having trouble with their roses. This year I've lost two rose bushes and out of the ten I have left in the back garden, I have only one rose!!!!! The rubbish weather we are having helps not at all. At least the birds are happy because there are so many aphids!

    1. Rain rain go away. Perhaps by late summer it will perfect weather.