Remember those sweet little yellow squash babies I'd hoped would make it? Three days later, they've succumbed to the same scourge as all the rest: blossom end rot.
I knew I should have picked them on the 4th. Grrr!
There's several theories as to what causes blossom end rot, which affects not just squash, but other curcurbits (melons, cucumbers), as well as veggies in the nightshade family (tomatoes, peppers, eggplant). Pretty much any plant that forms fruit is susceptible. From what I've read, blossom end rot is primarily a problem of calcium deficiency. Calcium plays an integral role in the formation of strong cell walls. Without adequate calcium, newly formed cells collapse and die. Because squash and other fruit grow fastest at the blossom end, that's where the problem becomes most apparent. As the fruit dies, bacteria, fungi and pests like my pill bug friends move in and make a big old hot mess of it all.
Unfortunately, as I've discovered, simply adding calcium-rich soil amendments doesn't always solve the problem. If the roots become damaged (through overly aggressive Garden Weaseling, for example), the plant can't take up the calcium. Both overwatering and underwatering can compromise a plant's ability to take up calcium from the soil. A soil pH that's too high reduces calcium uptake. And too much nitrogen-rich fertilizer just makes the problem worse, by pushing an already-stressed plant to Grow Faster! Grow Faster! Die Faster! Oops...
I don't believe lack of organic matter is contributing to the problem. The squash are planted in the same soil (Ladybug brand Hill Country Garden Soil) as the fruiting plants that are doing well - the Mickey Lee watermelons, the Juliet and Celebrity tomatoes and the pickling cucumbers - a soil rich in organic matter. I've watered the squash as often (or not) as the other veggies. I fertilized with Ladybug All-Purpose Fertilizer (8-2-4) once in May; perhaps that's too much nitrogen, but I doubt it.
The only other thing that occurs to me is that I purchased these squash plants as seedlings from a local nursery. Like most seedlings, they were planted in a peat mix. And as I recently read on a garden blog post (which I can't find now that I want to link to it), peat is wonderful at retaining water unless it's allowed to dry out, at which point it becomes a concrete-like root-suffocating substance impermeable to water. And in this drought, soil's gonna dry out at some point. (EDIT: I remember now: it was Cindy's RIPeat post at her blog, From My Corner of Katy, where I read about the hazards of peat in Central Texas gardens.)
OK, so I'm grasping at straws here. Lotsa talk, no answers. If anyone has any ideas for remedying blossom end rot, I'm all ears. I wonder if Michelle's dealing with blossom end rot over at 1600 Pennsylvania Avenue? Sigh...