jen1996 - mulching with leaves or dried grass clippings is a great idea as it keeps the soil moist which squash love! Squash are heavy feeders, so you need a complete fertilizer. In my area Dr. Earth or Whitney Farms are the brands. A 4# box is around $8 and a larger bag under $20 with 4x the amount at least. If you can keep it dry over winter it will last for next year, too. When I started using the granular organic fertilizer it made a huge difference in our vegetables as compared to just manures & mulch. Follow directions on the container, don't over do it. Even used coffee grounds feeds them a bit, but won't be enough to increase fertility very much quickly. Besides the fertilizer you can mix up a liquid compost tea that is easy -- a handful of your composted leaves in a bucket or watering can. I usually let it sit for a few days, but in your situation it would help to feed them today. Make 2 batches & let the 2nd one sit for a few days in the sun. It's fine to water with it daily as it's not too much fert, but just a little bit of instant feed. Hope that helps.

Thanks Dave... Yep, the guy who sold them to me when I bought them said "I think they're getting too much water, they need to get in the ground" So I bought them and took them home and put them in the ground. Then today he looked at the clippings and said "you haven't watered them since Saturday, you need to water them every other day and babysit them" Total contradiction.....It's apparent he has no clue, he's setting up a "blame the buyer" excuse to not honor the warranty. It fries my bacon....and yes, he seemed like an idiot. I'd rather trust you guys here who have dealt with Thuja Green Giants before. Is it possible that at my elevation (about 6500 ft.) that they could have plenty of water, but are being killed by the sun due to higher sun exposure rates due to altitude? Are they sensitive to that? (as in it's easier for a person go get a sunburn at high altitude) By the way, this particular nursery was the only one of 5 in my general area that even carried the Green Giants. Maybe that should tell me something.

You may want to repost this to the vegetable forum. There's lots of helpful people there.

Plants can be amazingly resilient; do give these a chance. If leaves are badly damaged, as in your fifth photo, go ahead and remove and destroy (don't compost) them, as they probably don't have enough chlorophyll-containing tissue to contribute to the upkeep of the plant. However, there is no need to remove the leaves if they still have a lot of undamaged tissue - just squish the borers inside the tunnels in the leaves; you might even be able to see them if you look closely. I know, yuk, but it's them or your zukes! Besides, that's what garden gloves are for, and they're inside the leaves anyway. I trust you made drainage holes in the bottom of that bucket; if not, you need to do that now. Be careful with the Epsom salt; don't over-do. The only yellowing I see in your photos is on heavily infested leaves, and may be a by-product of that infestation. On another social media site, someone shared a site with multiple charts illustrating how plants exhibit nutrient deficiencies. I'm posting it below in case Prof. Google hasn't already shared this one with you. (By the way, I've not had a chance tor review this yet myself.) http://bigpictureagriculture.blogspot.com/2015/12/plant-nutrient-deficiency-leaf.html Looking forward to more photos and wishing you the best of luck ... I've not even planted my zuke seeds yet! Heeled in some tomato plants in that spot and they appear to have taken over.