Powdery mildew dramas... don’t know what to do?

jo.pengelley

Hi all, I have 4 large borders which are new this year but several of my plants in one East/North East border appear to have been struck down by powdery mildew (centaurea montana Jordy and Alba, lupinus West C Masterpiece and Sanguisorba Tanna) other plants in the border seem fine - the affected plants are all spread out and not near each other. I have cleared around them and removed affected leaves but what else can I do? Is it possible that we have a source somewhere nearby that will keep reinforcing them? I recall losing all my beans and peas about 4 years ago to it (in a different part of the garden) and haven’t tried to grow them again since - but I have some in this year so 🤞. Would I be better to pull out all affected plants and replace with resistant ones? (Any suggestions for resistant plants?). I didn’t even think the Sanguisorba Tanna was susceptible 🤷🏻‍♀️ Bit worried - I’m new to gardening but have taken on a massive project relandscaping our garden, aside from the really bad soil (clay, and a vast amount of hardcore and builders rubble - which has been an epic effort to try and correct) this is my first major hiccough. Advice would be very much appreciated. Thank you

Dovefromabove

Different types of powdery mildew affect different types of plant so it’s unlikely to be spreading from one type to another. 

It usually affects plants that are struggling, mostly because of drought. The soil below the surface has been very dry this spring. You are gardening on clay ... I would give the borders a real soaking at least twice a week. Half an hour with a sprinkler or the equivalent. More often during warm dry spells in the summer. 

And of course, in the longer term, lots of organic mulching to improve the structure of the soil. 

Hope that helps. 😊 

jo.pengelley

Hi, thank you! Though they are mulched with ‘clay buster’ from dalefoot composts and are watered every other day at around 1700. Do you think they need more water? Or earlier? I’m watering grass seed on the lawn daily anyway... thanks again

Fire

Maybe try a  much longer watering (at the roots) but less often.

jo.pengelley

great, great, I’ll do that! Thick question but if I’m using a hozelock spray on a hose, how long would you put it on a plant for? Water tends to pool quite quickly on our rubbish soil. Thank you

Butterfly66

I was told to water each plant whilst singing ‘happy watering to you‘ twice to the tune of..... you’ve guessed it happy birthday .......then move onto the next. Any pooled water will gradually soak in or you could sing it once and then go round again for the second singalong.

A good soaking once a week is much better than more a little water more frequently. The latter just encourages roots to stay closer to the surface which then makes them more vulnerable to drought and reliant on you.

jo.pengelley

That is so interesting, and makes perfect sense. Thank you so much! I have dahlias in too (in another border) they seem quite thirsty and wilt easily, I presume if they wilt I should soak those too? Hope the few of mine affected by last night’s frost recover ☹️

Dovefromabove

Yes ... a good soaking so it gets right down to root level and below. 💦 

Fairygirl

Centaureas often get mildewy, even with a good watering regime, so don't worry too much.
Make sure you're not watering from overhead too. Always at the base unless it's cloudy. 
They guy who lives across from me has built raised beds and is trying to grow veg. I see him out each day 'spraying' the plants for about five minutes- in the sun. 
 
Definitely mulching regularly will make a difference, long term. It's better to improve the soil structure, rather than constantly feeding too   
Don't worry about a wee bit of frost. If frost is forecast at any time, try and water early on too, and then it's done it's job before temps dip again. Good luck with your project