Hardly any yard work to do here--it's snow shoveling tomorrow!
My best at-home workout purchase was a weighted vest. You can adjust the amount of weight on it and wear it for exercises. It's amazingly versatile and you can wear it on the treadmill, while doing pushups, squats, lunges, dips, etc. It can take just about any body weight exercise to the next level.
A resistance band (plus a dowel rod?) can get you in a good spot for bicep, tricep, back and chest exercises. I got a second-hand weight set on craigslist that I much prefer but a resistance band and a weight vest are a great bang for the buck and a space-saver too!
Now wearing a weight vest while shoveling snow? That's for the true madlad.