How has your black spot been?

Roses vary a lot in their susceptibility to the fungal disease, Black Spot.  This can be a killer and a reason why you cannot grow some varieties.  I use organic methods to cope with disease most of the time but I make an exception for my (our)  roses.  That means that I spray the plants most seasons from time to time and if the season is a bad one for black spot,  like this one has been (wet and cool), I try to spray every fortnight.

Two things affect how much black spot you get.  One is the kind of black spot you have in your neighbourhood; this can affect which varieties show resistance and which are relatively susceptible.   The other thing is the microclimate in the garden.  'Agnes' is a rugosa that often does not show a lot of the disease.  The 'Agnes' bush I have in the open border is fairly healthy but the one planted against the house is showing more black spot than just about any other.

So by looking around the garden at this time of year, you can see most clearly which roses are more resistant - the ones that are healthy even although they have never or rarely been sprayed.  The suscepts are those that are looking very sad even after spraying regularly throughout the season. The list below has the most resistant at the top and least resistant (susceptible) at the bottom.  Remember that this is according to infections observed in my garden over several years.

Tuscany Superb
Perle D'Or
Rose de Rescht
Blush Noisette
Rosamudi
gallica Versicolor Rosa Mundi
Ispahan
MutabilisRoseraie De L'HayPhyllis Bide
Brenda ColvinAgnesCupidWilliam LobbLittle White Pet
Old Blush ChinaStanwell PerpetualPenelope
Scharlachglut
Albertine
Mme Alfred Carriere
American Pillar
Windrush
Complicata

I use the systemic fungicide, 'Systhane' (active ingredient myclobutanil).  The chemical prevents new infection of healthy tissue but also has a curative effect on any disease already present on leaves and stems.

IIn 2016. I plan to use another systemic substance, the chemical Phosphite (also known as phosphonate, a salt of phosphonic acid).  This substance induces the natural defences of the plant.  The mechanism is fairly well understood and is known as Systemic Acquired Resistance.  This can also be seen when early infection of lower leaves of the plant can induce resistance in upper leaves and vice versa.  The resistance appears to be non-specific as the plant is protected from viruses and a range of fungal and downy mildew diseases including rose downy mildew. 

Tweet me if you have a comment about your findings compared to mine. @rudebotanical

Well, waiting for a spell of cold weather before planting the tulips didn't work. Up till today, there's been one frost, and we've had a month of wet and stormy but not cold weather. So, since the weather was having a rest today, I planted 30 greigii tulips: Toronto, Quebec and Girlfriend in front of the shed.

I also planted 10 each of Elegant Lady, Ballerina, Aladdin and Jacqueline in a wide row behind them. Roll on spring!

Dahlias 2013.  The most flowers from the big shaggy pale orange one we can't identify. A bit floppy as a cut flower. New Baby and Glorie van Heemstede didn't produce a lot of blooms. Karma Fuchsiana didn't either. Hillcrest Royal was good, and so was the large dark purple pompom. Taratahi Ruby was also very good. My favourite this year was the unnamed one we got from Hazel. It makes a very good cut flower, lasts well. They all responded very well to a liquid feel of tomorite at the end of August. Do more of that next year.

This year the plants grew much higher than ever before and needed more support. Remember that next year.

Our replacement dark blue plum sucker put on a reasonable amount of growth this summer, the best for years, though that's not saying much.

Department of good resolutions and new beginnings:
I have planted 10 Menton tulip bulbs in the bed by the Rosa Mundi. Six precious Sprengeri bulbs have gone into the "meadow", well marked and protected from squirrels by mesh. Sorbet which is like Marilyn should go in a pot. I have 40 lily flowered bulbs: Aladdin, Jacqueline, Elegant Lady and Ballerina for the bed beside the shed.
Along with them will go Toronto, Quebec and Girlfriend, but I'm afraid I've made a mistake in getting Greigii tulips: they might be too short for the size of the flower. We shall see.
Fifty allium sphaerocephalum (I think) have been put in everywhere, each one with a label, as well as 10 white allium in the north border of the conservatory garden.

I've started cutting down the dahlias and must remember to get some tubers of the orange one to Corinne in the spring.

Dahlias are starting, the consolation of August. Taratahi Ruby first off the mark, five foot high. Hillcrest Royal and New Baby both have flowers. Chat Noir is opening. We will finally see what we have after the hard winter for the tubers in the shed.

18 April.  This is how far we have got. The siberian-sourced hawthorn on the roadside is green. The larches show a green haze. The viburnum mariesii has small leaves. The hornbeam leaves are just sprouting. The native hawthorn is still bare, as are the birch, sycamore, oak, ash, beech.  This on a date when normally the countryside is fully green.
Daffodils haven't been stopped, thank goodness.

Spring. Not.

Garden news for 2013 so far. After a few pleasant days in Feb, January returned. March was a story of frost and bitter east winds.  No change so far in April.  Some roses are beginning to sprout a little and that's all. No sign of a leaf on a tree.  The daffodils have struggled up, brave souls they are.  In an average year, mid April sees all the shrubs and trees in leaf except the oaks.
The camellias at the top of the garden are flowering though. We're waiting for them to grow 8 feet high and wide like the ones at Bodnant. Fine feathers rhodo in that same border is looking well also.