Since they're cheap and come in bulk, we tend to waste a lot of vegetables and herbs in the kitchen. If you'd prefer to cut down on that a bit, a few kitchen staples are dead simple to regrow and don't need a full blown garden. In fact, these ones don't even require dirt.
You can technically regrow just about any fruit, vegetable, or herb from a scrap or seed. Most of us aren't looking to grow an avocado plant in our kitchen. More useful are the foods we tend to use every day—like green onions or lettuce—that don't take much time, dirt, or space to regrow. Sure, you can grab a bundle of green onions from the grocery store for 70¢, but why bother wasting that when you can keep a nearly endless supply that doesn't need much upkeep for free?
With that in mind, here are some sensible, easy, and useful plants you can regrow as long as you have a little sunlight and a glass of water. You'll want to swap these out with new plants every once in a while so you have fresh nutrients (or grow them in soil), but you should get a couple of healthy rounds out of them.
Romaine Lettuce
Lettuce is one of those staples that tends to get used in all kinds of meals year round so chances are you're buying a head once a week or so. Instead of tossing that heart in the trash when you're done, you can regrow new leaves.
Take the bottom of the heart and place it in jar with about a half-inch of water. Put that in a window sill near some sunlight. Then replace the water every one or two days. Within a few days you'll have some leaves sprouting up. From there, just let the lettuce grow, trimming off any brown leaves that might wither on the outside. When you have enough green leaves sprouting up, eat away. You can do this with most other red and green lettuces as well.
Green Onions
Green onions are the easiest food scrap to regrow. Just take the leftover green onion roots, drop them in a glass with enough water to cover them, and move the onions around so the roots are pointing down. Make sure you change the water out once every couple of days so they don't get greasy. Within about a week you'll have a brand new set of green onions. If you tend to top your food with green onions a lot, this is a pretty simple way to ensure you always have some around.
Garlic Sprouts
Garlic sprouts are usually chopped off and thrown away as a sign you've left garlic out for too long, but they're edible if you get the right bits. They have a nice, less abrasive taste than a clove of garlic and make a good topping when they're sprouted. The initial sprout is bitter and terrible tasting, so you'll need to grow them for a bit first. If you have a garlic clove with a green sprout coming out of it, pull it aside and put in a small jar with enough water to cover the bottom of the jar. Within a couple of days, the clove will produce roots, and shortly after the sprouts will rise up to a few inches tall. When they're at least three-inches tall, you can trim off about 1/3 of the shoot.
Fennel
Fennel has a strong enough taste that it's pretty rare you'll need more than just a small cutting from one. If you'd like to keep one around all the time, it's worth just regrowing one you have. Just take the bulb, put it in a cup, and fill it up with water so the bulb's covered. Stick that jar in the sun and within a few days it'll start sprouting up. Replace the water every couple of days and trim off a bit of fennel when you need it.
Leeks
Leeks are awesome for soups, and it turns out they're easy to keep around because they grow in water just as easily as green onions. Just take the base of your leeks, cover them in water, and leave them in the window with some sun for a few days. You should start seeing them sprout right away, and within a week or so you'll be able to trim off parts to use in recipes.
Photos by Vectormart, Nikiteev_Konstantin, JacindaWalker, anneheathen, fred_v, and cbertel.