Powdery mildew! :(

Yes, you're right it is bi-carb. Should have clarified that in my comment just in case anyone else needed to know but my mind is still on holidays!

I think I saved my peas!

I sprayed last week and then sprayed again yesterday as they still had a bit of PM but they have some new growth and new flowers so I think they will be fine.

Hurrah! what did you spray them with?

ericam wrote:I think I saved my peas!

Yes, do tell: what did the trick (other than persistence)?

I probably should know this but I am not sure.  Here is a picture.  Some of you will know immediately what it is.



Also what do I do about it?

That's what it looks like to me. Read back through this thread for advice.

What about potassium bicarbonate as a fungicide.

murarrie25 wrote:What about potassium bicarbonate as a fungicide.

Bicarbs are considered a preventative and not and eradicant. Any bicarbonate should be used with care as to avoid plant injury.
http://www.mastergardeners.org/publications/powderyMildew.html

After doing my research, posting a picture and having it verified, I mixed up a solution of 1 tsp. bicarbonate of soda to 1 qt. of water, put it in a regular spray bottle and went out to spray my pumpkin leaves.  The powdery mildew had spread to most of the leaves by this time and as you know pumpkins have lots of leaves.  So I started spraying and then had to mix up more solution.  My son took over and sprayed the rest.  What a cool son!  This morning I was dreading going out to water.  I was so surprised when I saw that most of the powdery mildew was gone.  I sprayed again where I saw it and still need to finish but it looks like the powdery mildew is on the run and I may not lose my pumpkins just yet.

The powdery mildew on my pumpkins is everywhere. I just sprayed more Neem after I removed a lot of the leaves. It is so sad.
So far I have two pumpkins that are growing and turning orange.
It is also on my butternut squash plants and I have 2 butternut squashes doing okay.
The powdery mildew did do in my cucumbers and I had to toss the plants. 

Dunkinjean, what you're experiencing is what we went through last year.  Ugly happening, I'm here to tell 'ya.  However, weather is different this year and we have NO mildew problems.  Last year's PD was the first major outbreak of this killer in years and years.  My thinking is there must be a "perfect storm" confluence of humidity, temperature, rainfall, spores to be a major problem.  Having said that, we did cut back in a major way with planting of squashes.  So far, zucchini, South American summer squash, Australian Butter, Portimarron and one Pennsylvania Dutch Crookneck have no sign of PM.  Last year I was spraying every three days!  My hearfelt thoughts are with you in your battle.  Nonna

Tricia that is awesome results. I know that made your day! I lost a cantaloupe plant to pm so I will definitely remember to try this out if pm rears it's ugly head in my garden again. lol

Dunkinjean It is so sad when your garden gets "sick". I hope you are able to get it under control soon and not lose any more plants.

PM seems to be a staple at my house.  I lost just about all my squashes to it this year and last.  A butternut is trying to form a couple more fruits before succumbing but it'll be a race with a photographic finish.  The Patty Pan is hanging on even though all the leaves are covered with PM.

My cucs are in sad shape, too.  I cut them back and spritz them with baking soda after every rain now.  I'm hoping to get the 6 cucs that are forming to grow up before it's over.  Another photographic finish.

Next year I'm going to try PM resistant seeds from Johnnys.  If that doesn't work I'll stop growing them.  

CC

Dunkinjean and CapeCoddess I hope your battles are won! You certainly have been hit hard!  I wonder why mine responded so quickly. I bet there are probably different strains of powdery mildew. I haven't had a chance to check. I know the powdery mildew is rough on the plants and so is/are the treatment(s). I think I read (but again don't have time to check) that spraying manure tea will help strengthen the plant. It may be worth a try and something I may try also.

TxGramma so sorry to hear about your cucumbers!

Nonna that's funny you should mention a perfect storm.  We had a wonderful lightening and thunder storm and rain the night before I noticed the PM.  I wonder if it came in on the storm.

I think the humidity here is just too high for these plants. 

Here's my cukes today, soaking wet with fog, with the Patty Pan on the far right of the trellis: 

There are 2 butternut squash fruits showing on these vines which are climbing a rhodie hedge.  The squash leaves are all dead up to the first fruit on the left:

Once everything dries out a bit I'll spritz them again with bkg soda since we got 1/4 inch of rain yesterday, enough to wash it off.  

CC

I was not able to catch the Powdery Mildew in time since it happened while I was away for about 2 1/2 weeks.
I guess I need to rethink the amount of time I am away from my garden!

From Smart Gardener -
http://www.smartgardener.com/plants/776-cucumber-straight-eight/diseases/781-powdery-mildew

This common fungal disease most often attacks the cucurbit family and beans. It is most often found in mid to late summer and unlike most fungi it doesn’t need a lot of moisture. It starts out as small, white, round, powdery spots on the top sides of older leaves, but quickly covers whole leaves (top and bottom) and stems. In severe cases the leaves turn brown and die. It also occasionally infects fruit, but more often the damage to fruit is caused by sunburn due to loss of leaves (this also reduces fruit production of course). Powdery Mildew doesn’t usually kill the plant outright, though it slows it down and makes it less productive.

Powdery Mildew is most problematic in shady, humid, areas with poor air circulation, so give your plants good air circulation (provide support for climbing varieties is important). Remove infected leaves to reduce the spread. The fungal spores overwinter on plant debris, so clean up the beds in fall. Also make sure the plants are well fed and watered. Some cucurbit varieties are resistant (marked PM). You can try controlling the infection by spraying affected leaves with compost tea or urine (diluted with 4 parts water).

CC

I want to know if it is okay to put the leaves in the compost. My garden is winding down and just in the last week the PM started on the remnants of the snow peas and has now started on the bee balm. I'm going to spray with the peroxide and or the milk suggestion.

Anyway, I just want to know how it will affect compost.

Yes you can put the affected leaves in the compost. Powdery mildew is everywhere.

camprn wrote:Yes you can put the affected leaves in the compost. Powdery mildew is everywhere.

Would you believe that I have never had it before? This summer has been a very unusual one where I live. First it was too cold and wet and now we have had very little rain and intense heat. I think that the humidity has been a factor here. On the hot days it has been very high and at night it hasn't let up.

Okay, next week it will be time to pull the snow peas and compost them. Hopefully the spraying will revitalize the bee balm.