We adore this blog post from EatingWell!

Instead of tossing those veggie stems, butts and seeds, give them new life by regrowing them into plants. These gardening tips will help you get started.

1. Celery

Remove roughly 2 inches from the base of a bunch of celery and place in a shallow bowl with water, spraying the top daily to keep it moist. Replace with fresh water every couple of days until a new root system emerges, then transplant into the ground.

2. Herbs

Most herbs will propagate through cuttings—snip at a node (where sections of the plant merge), and place the cut portion in a jar of water on a windowsill. Replace the water every one or two days until roots emerge, then transplant to a container or the ground.

3. Garlic

Garlic is one of the easiest foods to grow from kitchen scraps—simply take cloves and place them pointy-side up in the ground, 4-6 inches apart. Plant them outside in fall before the first frost, and enjoy fresh garlic the following year. Plant them inside in a container any other time and enjoy garlic greens, but not a full head.

4. Ginger

If you've ever bought the exact amount of ginger you need for a recipe, you're our hero. If you're like most of us and always have some left over, give it new life by planting it and growing more! Soak the root in warm water overnight, then plant it sideways in a container, cover with soil and place in a sunny spot. Keep the soil consistently moist, and within several months you'll have enough ginger to harvest.

5. Green Onions

If you're only using the green part of the onions, retain the white part with a small amount of pale green and place it in water on a sunny windowsill. Refresh the water regularly and use green portions as they grow, or transplant into a pot with soil for more extended use.

6. Lettuce

If you typically throw out the base of a head of lettuce, cut it away from the leaves and place in a bowl of water. Replace the water every one to two days, and within two weeks you'll have enough fresh new leaves for a sandwich or side salad. Note: This will not regenerate a new full head of lettuce, but it will help extend the life of what would have otherwise become compost or trash.

7. Peppers

Save the seeds from your next bell or hot pepper. Plant them directly into soil, and water them regularly. Once a new plant emerges, transplant it to a larger container or outdoors, where it will thrive best in direct light and warm temperatures.

8. Potatoes and Sweet Potatoes

Plenty of us have started growing new potatoes by accident—raise your hand if you've ever left a bag in the back of the pantry for too long, only to find them covered in sprouts. Take a more intentional approach by cutting potatoes into 2-inch pieces and letting them sit on the countertop for a couple of days to dry. Sow directly into the ground in early spring, and enjoy buttery homegrown potatoes in early to midsummer.

9. Strawberries

Carefully cut the outer skin (containing the seeds) off the berry, or extract seeds using tweezers. Place the skin or seeds in a container with soil, cover with soil, place in a sunny spot and water regularly until sprouts emerge. Transplant the sprouts to a strawberry pot or outside garden in springtime.
 

10. Tomatoes

Simply plant the seeds from your store-bought tomato into a small pot, keep well-watered on a windowsill, and wait for a new plant to emerge. Once the plant reaches several inches tall, transplant it to a larger pot—or outside once the threat of frost has passed.
 

11. Turmeric

Like ginger, turmeric is a rhizome, meaning you should plant it sideways to allow its root system to spread horizontally. A tropical plant, turmeric will thrive best indoors in most parts of the United States. Put it in the warmest spot in the house—it prefers temperatures well into the 70s and 80s. You may need to place it under a grow light and/or heating lamp, or purchase a germination kit with an incubation lid, heating tray and light. Keep the plant consistently moist, spraying and watering it regularly. Harvest when the plant begins to dry out after several months.