Why are my zucchini leaves not opening to their fullest?

[SydneyGee]

Hello,

I have a couple of ailments in my garden right now, nothing major. Two of my zucs planted next to a tomato never really opened their leaves to the fullest, and always looked a bit spindly/dropping flowers/baby zucs are rotting off. Recently, one of them has powdery mildew, and is spreading to the other zuc. I uploaded a photo of the two unhappy ones, and the happy one. Note: The white spots on the happy one are NOT mildew, they look like just lighter colors of the plant... so far every zucchini I have planted looks like that. Even some photos of healthy zucs I look up have that. But I am not sure what it is...

Other info: I have been fertilizing every three weeks with an organic veggie fertilizer. They all were planted in very well tilled soil, with added topsoil/compost, and get watered around every 3-4 days depending on heat and wind. Recently it's been in the 90's and decently breezy so a few plants have been watered more (the squashes, zuchs, and watermelons).

I will post another thread on the squash plant in question so as not to get confused.

 

[Chuck]

Hello,

I have a couple of ailments in my garden right now, nothing major. Two of my zucs planted next to a tomato never really opened their leaves to the fullest, and always looked a bit spindly/dropping flowers/baby zucs are rotting off. Recently, one of them has powdery mildew, and is spreading to the other zuc. I uploaded a photo of the two unhappy ones, and the happy one. Note: The white spots on the happy one are NOT mildew, they look like just lighter colors of the plant... so far every zucchini I have planted looks like that. Even some photos of healthy zucs I look up have that. But I am not sure what it is...

Other info: I have been fertilizing every three weeks with an organic veggie fertilizer. They all were planted in very well tilled soil, with added topsoil/compost, and get watered around every 3-4 days depending on heat and wind. Recently it's been in the 90's and decently breezy so a few plants have been watered more (the squashes, zuchs, and watermelons).

I will post another thread on the squash plant in question so as not to get confused.

On the first picture I don't know why the leaves are curling, possibly wind burn but on the second picture the IS powdery mildew. Google images for powdery mildew on zucchini plant. It is classic.

 

[SydneyGee]

On the first picture I don't know why the leaves are curling, possibly wind burn but on the second picture the IS powdery mildew. Google images for powdery mildew on zucchini plant. It is classic.

It looks nothing like the powdery mildew on the other plants though, which is weird... The "mildew" on the big happy plant looks more like raised white scales of the leaf. The mildew on the smaller ones are powdery and look like mold. Because no matter where my zucchini is I can't seem to avoid it. I don't get the leaves wet and they are not too close (last time the two plants were 3 feet apart). How can I avoid it?

 

[Chuck]

It looks nothing like the powdery mildew on the other plants though, which is weird... The "mildew" on the big happy plant looks more like raised white scales of the leaf. The mildew on the smaller ones are powdery and look like mold. Because no matter where my zucchini is I can't seem to avoid it. I don't get the leaves wet and they are not too close (last time the two plants were 3 feet apart). How can I avoid it?

Can you get close up pics of both plants leaves? Does anything wipe off of the leaves on either plant?

 

[SydneyGee]

Can you get close up pics of both plants leaves? Does anything wipe off of the leaves on either plant?

Nothing wipes off, it feels exactly like the leaf.

 

[Chuck]

Nothing wipes off, it feels exactly like the leaf.

Some varieties have a natural spotting that looks just like powdery mildew. I think the following link will be of help in determining if the spots are natural or PM
http://frontrangefoodgardener.blogspot.com/2010/08/telling-powdery-mildew-by-its-spots.html

 

[SydneyGee]

Some varieties have a natural spotting that looks just like powdery mildew. I think the following link will be of help in determining if the spots are natural or PM
http://frontrangefoodgardener.blogspot.com/2010/08/telling-powdery-mildew-by-its-spots.html

The first photo looks just like my happy zucchini!

The small, unhappy plants definitely have PM. It's soft and fuzzy and wipes off. Cool to know the bigger one just has silvery variations. Thank you!

 

[Tjohn]

My Caserta squash plants have that silvery variation on their leaves, but none of the other squash in that area do. They are not next to each other in the rows, but they each have it. I think it's just the way they grow as they are very healthy looking.

 

[Chuck]

My Caserta squash plants have that silvery variation on their leaves, but none of the other squash in that area do. They are not next to each other in the rows, but they each have it. I think it's just the way they grow as they are very healthy looking.

If it doesn't rub off or smear and is on the bottom of the leaves too it is probably ok.

 

[SydneyGee]

I pulled the zucchini closest to the tomato plant, as the PM was getting bad and the tomato plant was starting to cover it. I also fertilized, so hopefully this will help the other zucchini. Will keep an eye on it.

 

[Stink Bug]

Spray with epsom salt.
See if that helps.
One tablespoon per 4 litres of water and foilar spray them.
Zucchini plants always look like they have powdery mildew but isn't always the case.

 

[SydneyGee]

Spray with epsom salt.
See if that helps.
One tablespoon per 4 litres of water and foilar spray them.
Zucchini plants always look like they have powdery mildew but isn't always the case.

The larger of the two have silvery leaves that are typical for certain zucchini plants, I found. The smaller who has no disease problems so far and I fertilized heavily is still not really opening up...

 

[Rey]

I am a new gardener as well and sometimes I do see the leaves closes like that but they open. What I have seen in youtube which makes sense is that if the sun is too hot, the leaves curl or closes like a cone to protect its photosynthetic area from burning.. Mine does that when the sun hits at mid day but it is under a big pine tree so as soon as it gets some shade the leaves do open..