Trim the green part of the chives from the top to use in your recipe, leaving 2-3 inches of green sticking up from the bulb. Plant the bulbs in a pot with ample soil.
Place the pot near a windowsill that gets ample light and water the plant every few days—don't worry, chives are pretty drought-resistant, so you don't have to water them every day. Be sure to trim the chives when they grow too tall, or the roots won't take and the plant won't flourish.
Snip a stem off the mint plant so it measures about 3 inches lengthwise just below the leaf node (where the leaves begin to grow). Remove the lower leaves for use in your recipe, but leave on a handful at the top.
Place the stem in a glass of water on a windowsill that receives plenty of light. Your mint will develop roots within a couple of weeks. Be sure to change out the water when it starts to look murky to keep your plant healthy.
Cut a stem of parsley to around 3-4 inches long and leave a few leaves on the top for regrowth.
Place in a glass of water in a sunny spot on your windowsill.
Transfer the cuttings into soil when roots appear.
Cut a stem measuring 2-3 inches long; just below a leaf node. Remove all leaves except for the ones on the top. Also, be sure to remove any flowers, since they are a drain on resources (water and sunlight).
Place in a glass with water covering at least one of the leaf nodes (this is where the roots will come from). Roots should appear within a week.
Like basil, cilantro can grow roots if the stems are placed in a glass of water. Once the roots are long enough, just plant them in a pot. In a few weeks new sprigs will be starting, and in a few months you'll have a full plant.
Lettuce, Bok Choy and cabbage
If you have a stem from a head of romaine lettuce, Bok Choy, or Cabbage that's still intact, place the stump in a bowl with about ½ inch of water and put it on a windowsill. You'll start to see new leaves in about 2 weeks, and they'll be full grown in 3 to 4.
Take the base from a stalk of celery, rinse it off, and put it in a shallow cup of warm water on a window sill. Change the water daily and keep an eye on it to see if any regrowth begins. As you can see from the photos below, there were significant signs of regrowth within five days.
Place a budding clove (or even a whole bulb) in a small cup, bowl, or jar. Add water until it covers the bottom of the container and touches the bottom of the cloves. Be careful not to submerge the cloves in order to avoid rot. Change the water every other day and place in a sunny area.
After a few days, the clove or bulb will start to produce roots. Sprouts may grow as long as 10 inches, but snip off the greens once they’re around 3 inches tall. Just be sure not to remove more than one-third of each sprout at one time. They’re tasty on top of baked potatoes, salads, in dips, or as a simple garnish.
Scallions (Green Onions)
In as little as 5 days you can completely regrow a full scallion (or green onion) from the scraps. Leave about an inch attached to the roots and place them in a small glass with a little water. In a few days, you'll have all new scallions.
Hope this guide gives you motivation to start a new hobby, or continue an existing interest in growing plants and food. Re-growing a plant you already paid for is a no-brainer! Produce is expensive, and you never know what it was treated with. Start your own organic, healthy, and inexpensive herb and veggie garden.