One fun way to reduce food waste is by turning old produce into home gardening projects. Many of the scraps we throw away can actually be given new life with enough time, water, and sunshine. Here are five fruits and vegetables you can regrow at home.

1. Avocados

After (safely) removing the pit from an avocado, hold onto it and grow your own avocado tree at home. Start by using four toothpicks to suspend the seed atop of a glass of water. The pointier side of the pit should be facing up and the bottom half should be submerged in the water. Wait two to four weeks—changing out the water every five days—for the seed to crack open and sprouts to emerge. Your tree is ready to be transferred to a pot with soil when it's about six inches tall.

2. Green Onions

The best way to stretch a bunch of green onions for all its worth is by regrowing the scraps. Save the white ends of your onions and submerge them in water, with the roots at the bottom of the glass and the chopped sides poking past the surface. Place them in a sunny spot and watch them grow. To keep the water from getting slimy, refresh it daily.

3. Celery

Like green onions, celery needs a cup of water to start the regrowing process. Stick the reserved base of your celery stalk in a glass, taking care to replace the water once a day. A new stalk will eventually start to grow from the center of the base. It should be ready for potting in as little as a week.

4. Sweet Potatoes

To grow your sweet potatoes at home, you first need to cultivate slips. Slips are sprouts that grow out of old sweet potatoes, and they're used to propagate new ones. You can grow your own by taking half of a sweet potato and suspending it over a cup with toothpicks, with the cut side submerged in the water. Leave the plant in a sunny spot until your slips have sprouted. You can harvest them by gently twisting them off the potato and submerging them in a new water glass. Slips with roots that are roughly an inch long are ready to be transferred to soil.

5. Pineapples

By saving the tops of your pineapples, you can grow tropical fruit in your backyard. After removing the bottom leaves and any excess flesh from the top, plant it in soil. Pineapples don't need much water to grow, but they do require lots of sunshine and time. This project doesn't pay off as quickly as the others on this list. If all goes well, your pineapple will be ready to harvest in 20 to 24 months.