Pallet wood is good if it's what you have on hand but just be sure it's not treated, a lot of them are. You wouldn't want that in your vegetable garden! Also beware that they won't last but a couple years. That cheap would will deteriorate pretty fast. Again, not always a bad thing and they definitely serve a purpose, but being aware of the shortcomings is essential. I got peas, dill, and parsley planted outside yesterday and tomatoes, peppers, eggplant, and leeks started indoors. Everything outside is covered in plastic since we not even close to out of the frost window yet. I need to go buy more plastic to finish my row covers, and I still need to get a cutting blade for DH's angle cutter so he can cut some expanded metal sheets I got for trellises.