My “reward” for going to the Malvern Spring Show last week was the virus Gardening SIL was going down with as we wandered around lusting after plants and planting schemes. So I’ve spent most of the past few days in bed feeling sorry for myself. Even then I couldn’t quite bear to delegate the task of the evening watering to anyone else, so was to be found tottering around the greenhouse and coldframe after dinner spilling water and checking on the squash and tomato plants. Yesterday I finally had the energy to head outside for a spot of gentle planting out of tomatoes, something which I planned to finish today and then blog about – I’m experimenting again. No great surprise there. But as I pottered about on still wobbly limbs clearing up after myself I had my first proper look around the rest of the garden in a while. I’d taken loads of photos for GBBD, but was rather distracted by my new purchases from Malvern. I only took one photo of Knautia macedonica, a plant I have loved and have been raving about ever since I grew it from seed last year. The reddish-purple button flowers float above dissected leaves on wiry stems, and attract bees and hoverflies.
I didn’t include the photo on my post, it was slightly out of focus, the post was already long, even by my standards, and besides, I thought I’d do a post about it later in the year, when more of the flowers were fully open and the Allium sphaerocephalon it was growing alongside was out. I didn’t notice anything amiss, but there again, I was already feeling distinctly “off”. Imagine, then, my shock when I realised this previously wonderfully healthy plant was now looking like this:
This is not a plant that is meant to have silvery foliage. A closer look reveals the strange destructive beauty of powdery mildew.
One plant was entirely silver. The neighbouring ones, at first glance, didn’t seem too badly affected. Wrong!
I was despondent. But double checking what I thought I already knew confirmed that the best course of action was to dig the whole lot up and discard, and not on the compost heap. Not quite the harvest I was hoping for from my garden.
Its largely my own fault. Despite the fact that the word “mildew” conjures up images of damp, dank places, powdery mildew thrives in dry conditions where plants have insufficient air around them. It isn’t really a disease as such, but a fungus. In fact, the one saving grace is that it is a family of fungi with similar results, and each tends to stick closely to its own chosen “victim” – so surrounding plants of a different species tend to be unaffected. I knew back last year that I had planted these Kanutia too close together, they surprised me by their rapid growth, having started out life last April in 3cm pots. The close quarters coupled with the long dry spell produced ideal conditions for the spores to multiply, which they clearly put great energy in to. All three plants had to come out, and then I had to tackle the many self-sown seedlings.
The final tally was three large plants, half a dozen seedlings, filling two large black bin bags. And one disgruntled gardener.
I then had to check on the health of the other seedlings and plants. The plants are on the opposite side of the pond – they appear to still be healthy, although much smaller than their fallen siblings. I’ll keep a close eye on them.
I can tell I am a little paranoid now, as the photo above had me racing downstairs again to check the stems, as they appeared to be silvery. Fortunately just a trick of the light on the hairs that cover the stems. The seedlings are even further away from where the affected plants were growing, and also appear to be healthy. Again, I will be inspecting them closely each time I water them. In the mean time, I now have gaps where there was lush growth.
Although it is tempting to replant more Knautia, I am concerned that the fungal spores may still be hanging around and could destroy the new plants too. I might use the space for some of the Dahlia ‘Bishop’s Children’ seedlings that I was intending to plant up at the allotment. I’ll think about it – I need time to mourn (!) – but this has been a big wake-up call as to just how quickly pests and diseases can take hold in the garden. Never turn your back for long! I begin to dread my next visit to the allotment…