Hello Andrew. Well for starters, what zone are you in and where are you located?

Those pots you are using seem a bit small for summer squash and they appear to only be filled halfway. You should always fill them to the top before planting, so the roots have more room to grow.

Now in zone 6a, where I'm located, this is the time of year where downy and powdery mildew start to rear their ugly heads. There's really no way to stop it from happening unless you use preventative measures. You can slow it from spreading using fungicide, but usually the mildew ends up winning the battle.

Hey Chris,

I'm in zone 7A. The pots are 5 gallon pots. Would you have recommended larger? Would it be too late to add some additional soil, or is it too late at this point? Again, first time planter so I'll learn my lessons moving forward. I just find it weird for the leaves to be dying, but new leaves and flowers still forming forming.

We've all been there. Yes, I would've used larger containers. 5 gallon containers are ok for something like peppers plants, but squash plants get considerably larger. You need something like 24" diameter pot for those, which would probably be something like 15-20gal container.

Those squash plants look pretty small right now and August 1st is a bit late to start them from seed. If you had planted a seedling on August 1st, you may have gotten away with it, but those containers just aren't big enough for them to thrive.

Next year I would start them in late May or early June, depending on your last frost date, and in bigger containers. They are also heavy feeders and will need a good balanced fertilizer of NPK. Container gardening needs a lot more tending to than gardening in-ground. They need to be watered and fertilized more frequently.

A good start though! You clearly did some research on vine borers and disease, which is great. You used potting soil, which is good. You would be surprised how many people make the mistake of using garden soil in their pots. Next year you'll have much better results.

I'd say you have both fungal issues and issues related to growing in containers (i.e. too small a pot, too much/too little water, not enough nutrients -- containers are challenging for a beginner, they require a constant careful balance of water and nutrients.)

I will always start my cucurbits as early as possible to get ahead of the fungal issues, and even the borers which have had heavy pressure here in August for me.

I'm not sure what to suggest, I would leave a recommendation to someone with more experience growing in containers.

I am not keen on Miracle Grow soils. Search Youtube on mixing your own potting soil vs Miracle Grow experiments and it may change your mind about ever using that product. The problem is buying soil in a bag is the easiest method. Not all bagged soil is the same though. A good recommendation is mixing 1/3 perlite, 1/3 peat moss and 1/3 compost from a variety of sources for a potting mix.

I have grown pumpkins very successfully in extremely confined spaces. This year I had several volunteer seedlings from my compost, and not knowing where to put them stuck them in the holes in the concrete blocks surrounding my hugelkultur beds. They have grown like crazy, and I now have pumpkin vines running the length of my beds with numerous pumpkins on them. I may just be lucky, though. Oddly, the zucchini and cucumbers in the beds themselves are starting to get hit with mildew. The pumpkins, however, don't seem to have any issues.