My Summer Crookneck has a bad attack of the mildew.
Could I hinder its progress by cutting off the affected leaves or shall I even pull it entirely?
Trouble is my Queensland Blue which is still beautifully verdant is touching it and I don't want that to catch it. And if that catches it, there's a Kamo Kamo and a Tromba di Albengo on the other side of it and it might pass it on.
If you don`t want to use a proprietary (and non-organic) fungicide, then try spraying the affected plant with either:-
(a) Milk diluted 1 part milk to 9 parts water
(b) Urine diluted 1 part urine to 4 parts water (obviously cheaper than milk)
Then pick off the worst affected leaves - but not too many.
My six courgettes including Crookneck are DEAD r.i.p.
they succumbed to mildew :(
Hey ho always next year :)
I would cut off the affected leaves providing you don't remove more than 25-30% of the total leaves.
This will also allow more air to circulate around your plants which has probably been the cause of your problem in the first place.
It is that time, there is very little that you can do about Powdery mildew and at best it will give you only a short time.Downy mildew earlier in the season is the bigger worry and worth putting up a fight for.Pick off what you can see and maybe with a bit of luck you can stay ahead of it for another couple of weeks or so, the others probably already have the spores on them.Once it is there it is quite rapid.Sadly it is telling us the season is drawing to a close.
XX Jeannine
It's all very sad. I do feel autumnal.
I can't believe my Queensland Blue will be cut down in what still looks like its prime :(
Still, I've got two whoppers on it - hopefully they'll mature OK, won't they? I suppose the smaller ones won't quite make it. And the other kamo kamo has decent sized squashes, turning orange so that's fine.
I tried the milk thing the first year I grew anything and it seemed to have not much effect.
I guess it's the weather and time of year, squashes on other plots seem to have gone entirely.
Thanks for the replies...
early pea, Please do not just give up because of the more "abandon all hope" replies. Certainly it`s nearly autumn, and certainly powdery mildew can be expected to start appearing, but there are still things you can do.
For those of your cucurbits that do not yet have mildew a weekly spray of 1 teaspoon of baking soda (sodium bicarb) dissolved in a litre of water (or potassium bicarb is better if you can get it) will provide some preventive protection against actually getting powdery mildew.
For any that have mildew, I forgot to mention the dreaded marestail. Mix 28 grams of leaves, stems and rhizomes in a litre of boiling water, leave to stand for 24 hours, strain and spray directly onto the plants.
All of the remedies I mentioned in bothg my postings are well known specifics, they have been recommended at times by the HDRA, and while they are not cast iron certainties (is anything anyway in gardening?) they are well worth a try before you listen to the doom merchants
Excuse me.. abandon all hope replies.. I feel my statement was not abandon all hope. Their is a huge difference between prevention than from cure..We are almost into September and you are in the UK. I do feel after 50 years of growing squash I may just have a wee bit of experience.
Doom merchants. come on.. how many times have you actually cured Powdery mildew on squash in the 3rd week of August in the UK..not what someone else has done. I mean what have you cured yourself.
The UK climate is bang on for powdery mildew even copper spraying throughout the whole season is unlikely to stop it,the spores all all around, from peas to apple trees, even the brambles have it, it is carried on the wind and in the rain.Your plant has about 2 weeks before it will succumb, taking the first bits off and getting some air to the plant may help a bit, but you still have to bleach your pruners and even your wellies in an attempt to stop it.
If spraying it has be every inch of the plant, stem, fruit, leaves, underneath and on top, every scrap of foliage, and has to be done early in the morning so the plant is dry at night,watering has to be done early morning too and dew has to be well dried off..sorry but I disagree there is much hope, try by all means if you can in fact get every scrap of foliage in your squash jungle.
Abandon all hope and doom merchants..this is crossing the line, a bit it is rather rude, and could well prevents folks from posting with a different opinion to yours which is not the aim of the forum.I don't agree with you and have many years of experience behind me..many more than HDRA growing squash actually, and I have tried many many recipes for this problem. I am not infallible by any means but being realistic, if buying one or two weeks at most at this time of the year is all one can reasonably expect and that with a great deal of work and luck, I feel it more prudent to give help on rescuing the fruit that is there and help with advice in delaying the following season.
I would advise folks to try whatever they can to prevent it, however your weather,yor growing season length, general atmosphere and very close planting is not working with you.To get some of the squash currently being grown by A4A ers to maturity genarally is truly fantastic but powdery mildew is a fact io life like blight and is part of growing many things.
I personally shall continure to strive for a cure and a good preventative for it as I have always done.In the meantime I shall give advice based on my years of growing.
I do not consider myself a doom and gloomer, nor do I feel I suggest abandon all hope, if I did I would not still be growing squash after half a century.
It would be fantastic to hear anyone post to say,from personal experience, they have cured or delayed it, not from books or articles but hands on doing in their own garden.I would truly be cheering but I think we are along way from that.
In the fields around me the pumpkins are turning orange as they do each year, this is a big pumpkin and squash commercial areaI see fields and fields of them,and those pumpkins plants all have mildew, it is what usually finishes the season off, like frost kills the tomatoes.
You have done brilliantly to get your Quensland Blues to thsi point , that isa big feather in your cap, the smaller ones that don't make it you can eat, they just won't store.Bear in mind the length of the season Queensland Blue need, it can be like chasing rainbows sometimes and you have done it. Once the plant has mildew the fruit cannt absorb nutrients from it.
With respect.
XX Jeannine
Some varieities are more susceptible than others. I have never seen courgettes Clarita with mildew even when others are smitten all around.
I use nettle tea as a prevention but not sure it helps once the plant is smitten. The problem is that the slugs seem to home in on the plants as well.
Quote from: Jeannine on August 23, 2010, 00:14:53
It is that time, there is very little that you can do about Powdery mildew
Is how you started your posting, and that is what I regard as an "abandon hope" message. You then justify this by dismissing all the HDRA remedies on the basis that you have been growing squashes longer than HDRA - 50 years no less.
Surprisingly Lawrence D. Hills, of whom you may not have heard, but who founded the HDRA, was growing (inter alia) cucurbits some 25 or so years before your half century commenced, and by the time your experience commenced was a noted contributor of advice on horticulture. I cannot claim quite such experience as I only started growing cucurbits in the late 1940s, although this also would seem to predate you slightly.
When Lawrence Hills started gardening proprietory fungicides were notable by their non-existence and he used what we now consider organic remedies - this was also pretty much the case when I started.
In those days no Harvest Festival was complete without its collection of cucurbits, and Harvest Festivals were NOT held in August, but around mid-September when the farmers had finished harvesting. Yes, surprisingly we had powdery mildew in those days too - it isn`t something recently arrived just to test younger generations - but we used those remedies which you so deride, and yes, we provided the marrows, courgettes (which is what this thread was originally about) and cucumbers for those Festivals. My own personal preferences were the urine mixture I mentioned, and marestail, mixed at a quarter pound to a two and a half gallon bucket of boiling water, and brewed for 24 hours. Our spraying equipment then was rather primitive by today`s standards, and we had to think in gallons rather than pints
You say it would be fantastic to hear anyone post to say from personal experience that they have cured or delayed it. What on earth do you think my posting was about. I don`t advise things that I have not succeeded with myself. I certainly would never claim to have cured it, but along with a host of other gardeners at the time I certainly delayed it long enough to serve the purpose, and certainly until our Harvest Festivals.
And that is why I gave early pea the advice which I did.
It is extremely satisfying to find a use of maretail.
I don't know what to say :-\ I suppose the more experience growers have the more they will disagree, but I'm sorry you're offended Jeannine - your squash advice is always appreciated, as you know.
I did read the Hills book a while back and found it extraordinary; so far ahead of his time and it seems things in organic gardening have changed very little since.
On the one hand it does seem very early, down south, for squashes to be dying off compared to past years, but then I've only 3 years' experience. I don't think it's worth trying to save the crookneck from past attempts - am happy to pull it now to give the rest some air.
I would attempt to spray and prevent the others catching it, if it weren't for the fact that some of them are mighty, sprawling beasts now running the entire width of my allotment and dodging and scrambling over various obstacles to get there. I still might just try it even if it's just a really slim chance of extending its life slightly, only because I'm really very attached to my Queensland Blue in particular, spent half the summer stalking it.
Why does it need spraying early in the morning. Does it need to be absorbed on dry leaves/stems or not absorbed but coating the plant? If the sun comes up while the treatment is wet will it frazzle?
Quote from: Jeannine on August 23, 2010, 19:28:33
If spraying it has be every inch of the plant, stem, fruit, leaves, underneath and on top, every scrap of foliage, and has to be done early in the morning so the plant is dry at night,watering has to be done early morning too and dew has to be well dried off..sorry but I disagree there is much hope, try by all means if you can in fact get every scrap of foliage in your squash jungle.
Thanks, as ever....
Spraying has to be done in time to give the plant time to dry off completely before nightfall - and this is a standard requirement with almost every plant species at this time of the year when the mildew is waiting in the wings. Logic says that this shouldn`t be necessary when the spray is intended to fight the mildew, but it`s better to be safe than sorry. Even potato blight sprays are supposed to be sprayed early enough in the day for the plant to dry out before night.
However, if you are prepared to take the chance then I would suggest that sodium (or potassium) bicarbonate is a better prophylactic for a plant not already affected, the others being used to treat an already affected plant.
.....and does it frazzle the plant if you do it in full sunlight?
Thanks.....
No not really, and I am not offended in anyway, gardeners always have different views and get quite protective. We all do it, it doesn't mean anything.No-one holds grudges, well I know I don't.Winter squash is fairly new to the UK and gardeners have lots of views, I don't mind a bit. When I got my first WS seeds as a teenage of about 14 in the UK they came from Australia and no-one had seen them before, then I found the US had them and got more and so it grew, when I left the UK in 77 still the usual ones I saw around was marrow and courgettes,when I went back in 2000 I saw winter squash being grown , mostly butternut and I found a couple of seed houses that sold a few varieties..now winter squash is booming and that is great, most of the seeds purchased come from the US so it getting more and more all the time. I think that is wonderful, there are bound to be differences of opinion.
XX Jeannine
Jeannine, the original posting which started this thread was about powdery mildew on a Summer Crookneck squash, or as I tend to regard it, courgette, and all of my postings on this thread (except my remarks as to purely prophylactic spraying) have been directed entirely to the subject of powdery mildew on a summer squash, whose cultivational requirements are virtually identical to those of courgettes, which have been grown in this country since the 19th century and which I grew for 60 years.
Quite frankly I simply cannot understand what relevance the fact that Pumpkins were not grown here until after 1977 has to do with the subject.
I can reassure you, however, that should some member ask about the cultivation of pumpkins in Canada I shall leave it entirely to you as the acknowledged expert on the subject of growing pumpkins in Canada.
Garden organic (formally HDRA) now have nothing on their website about this use of Marestail.
They have a fact sheet on Powdery Mildew which is interesting but has little in the way of cures except Potassium Bicarbonate.
Personally my version of being organic does not like chemicals and prefers the witches brews.
The use of Comfrey has almost disappeared as well. I would not be surprised if Lawrence Hills was turning in his grave. I suppose the Elf and Safety does not allow them to suggest such things any more.
I have been growing courgettes for more than 38 years and still recommend resistent varieties. I have long since moved on from those I grew all those years ago. My first were Zucchini and then Golden Zucchini. Last year I grew Trieste from real seeds and after they completely wiped out I remembered why the advent of the F1 hybrids was such a boon.
I enjoy heritage varieties of beans but for courgettes there does not seem to be any need to go back to the stone age.
HDRA used to have a huge range of `witches brews`, most of which worked one way or another, but now they seem terrified to recommend anything which has not been approved by the anti-gardening gauleitters of Brussels. I suppose that it is a criminal offence to even advocate the use of urine without first coughing up about £10,000 to register my particular brand.
Potassium bicarbonate is very little use as a treatment for a mildew infection, but is better used as a purely prophylactic treatment. It may not be truly organic, but is far more acceptable than bordeau mixture, and other copper based fungicides.
Bordeau mixture, however inorganic it may be, of course, has to be officially organic or there would be no more organic potatoes, and the Soil Association would have to sack half the staff.
For anyone still in doubt after reading through this Thread I would suggest a careful perusal of the paper on the subject of bicarbonates at this address:-
http://www.attra.org/attra-pub/bakingsoda.html
This is a summary of various research projects on the subject carried out by genuine scientific research establishments, and is probably the most authoritative article you will find on the subject.
Anyway, out of adversity...... ;)
I got a surprise crop of these on composting my crookneck which was looking beyond help - we've had 2 inches of rain in one night and will have similar today.
(http://i1024.photobucket.com/albums/y308/earlypea/crookflowers.jpg)
Always meant to try cooking them, but feel wasteful eating babies....whipped some up last night.
Digeroo - Don't be put off growing a Summer Crookneck by this experience, it's a wonderful vegetable. Firstly, it is not a courgette, it's a winter squash eaten in the immature stage. Secondly, this is not in fact a summer crookneck I'm growing, but an accidental hybrid in a packet from Realseeds (wrong leaves, strange growth habit, stripy and not nobbly fruits). Last year's Crookneck produced wildly until it was cut down by a hard frost.
Beyond all of that, I could also see that its earth was bone dry but didn't water it - wasn't supposed to do anything for a few days because of a blow to my head. Just managed to pick beans and squashes. Birds got all my sweetcorn ::)
Thanks for the link Kepouros (I haven't read it yet, but I will).
Had a quick read. If I were to put this into practice how could I do it?
For proven pumpkin help, says baking soda without oil is ineffective - what kind of oil could be used? It wouldn't bind with the water anyhow without an emulsifier.
Or do I go for the spray for roses which uses 'a water solution of baking soda and insecticidal soap' - that I could do easily, but would it work on pumpkins?
If you have a decent local garden shop they may well have several oils in stock. However, in the UK they are mostly sold as organic pesticides rather than simply as neat oils. Virtually any plant/fish oil mixture sold as an organic plant pesticide or fungicide will do provided it is sold as a dilutable concentrate.
The one I know is VITAX Organic 2 in 1 which is sold as an organic insecticide, but you need to get the concentrate which you can dilute, and which contains its own emulsifiers.
If you prefer a neat oil, then NEEM is ideal
I also intended to mention, if you have powdery mildew on your tomatoes, then you might find the following of interest:-
http://www.ingentaconnect.com/content/bsc/jph/2003/00000151/00000003/art00005