I regularly put table scraps into our garden to compost but I don’t remember these squash! Any idea what they are? I have never seen them before. The photos show both a young and older squash of same plant.
Jackson County Oregon squash
Did you plant squash this summer, but not this variety? It is possible the source of your seedling had mislabeled the plant.
Did you plant different varieties of squash in previous years? It is possible that your common squash varieties cross-pollinated and came up with a distinct variety that probably won't be as tasty as the parent plants.
Squash is usually divided into two categories: "Summer squash" is the edible fruit used when immature as a table vegetable. Zucchini and crooked neck are two examples. The skin usually soft and easily pierced and should be eaten soon.
"Winter squash" is the mature fruit of squash such as acorn or spaghetti, often baked and used in pies. These squash are hard-skinned and can be stored for several months.
Comparing your picture to images of spaghetti squash on-line, I would guess you are growing a winter squash, possibly spaghetti squash.
I didn’t plant these squash. They came out of my garden randomly probably due to seeds in my table scraps. I didn’t plant a garden last year. This is my first year. I don’t have any other squash near it. Both squash taste like summer squash even when they seem to be more mature, having a hard exterior. I might let them go longer and see if they change into winter squash. They aren’t spaghetti squash. The inside is just like a summer squash when young. Here is a picture of the inside of the greenish orange squash.
As another expert, I strongly support Ms. May's idea that the seed from some previously consumed squash (i.e. the source of the table scraps from a squash you did not plant or grow) was the result of a cross-pollination with some other squash, or with a cucumber, or any other cucurbit family member such as a melon. Plants from such seeds do not always resemble their parents, especially if the squash was a hybrid product pollinated by another hybrid. We do not recommend allowing "alien" plants that spring up from compost or imported planting mixes to live. They can be carriers of disease (especially tomato diseases in "volunteer" tomato plants). They usually do not produce a fruit that is tasty. Your "squashling" looks similar to the inside of a melon; the green skin could have come from an acorn squash; the peachy color from a Hubbard Squash-- who knows? Best not to put seeds into a compost heap unless it is hot enough to render them infertile or turn them under as green manure where they would have conditions amenable to sprouting.