MINT: From one mint plant, one can literally get million mint plants through propagation. To propagate mint from cuttings, cut a young shoot about four inches in length. Strip away all the lower leaves and then just lower the bare shoot in some water. Within two or three days, you will see roots coming out from the shoot. Once some healthy roots are developed, put it out in garden, and a whole big mint plant will grow out of it. However, mint is a very aggressive plant though very beneficial to bees, butterflies and other insects. So, unless you have lots of use of mint in your cooking and/or looking for creating bees/butterfly gardens, do not put mint in your garden. It will spread very fast through under-ground suckers. So grow them in pots. Another point to keep in mind is that not all mints are suitable for all climates. There are many different types of mints; some mints can be perennial even in zone 1 while some mint will not even survive the chill of zone 7. So, if you are looking for perennial mint, you need to buy the mint that's suitable for your zone. One of the best mint-family plant that I have in my garden is the native bee-balm, and about which I will write later.
I'm now propagating five different types of mints through cuttings. You can grow such plants from cuttings to give away to your friends and families. Mint can easily grow in both shade or light; it can also be grown as beautiful hanging basket plants inside your house. So, you will have a plant which is not only edible but which will also make your room smell nice. And, they will grow and thrive throughout the year inside your house. To propagate from cutting, always take a fresh cutting from a leaf-node (node is the point on the stem where leaves grow, as shown in the second picture). In the third picture, you can see all the roots that have developed.
Not only mint but oregano, sage, rosemary, thyme and lavender -- all of these herbs can be propagated from cuttings like this. However, you cannot propagate parsley and cilantro from cuttings. I have also found that garden-sage, oregano and thyme can also grow in both shade and light; thrives as house-plants. However, lavender and rosemary really requires bright sun-shine.
Another easy plant to propagate from store-bought item is sweet potato. Take a small organic (not sure if inorganic chemical infested sweet-potatoes will behave similarly or not) sweet potato. Hang it in a cup of water by pushing in some stick to its side. Within a week, there will be roots growing; then within 2-3 weeks (or sometimes it can be 4-5 weeks also, just have patience; plants can really teach us how to be patient) stems and leaves will keep on coming out from the top part of the potato that is not in water. You can then put in the whole potato in the ground. However, the practice is to cut the stems (those which are about 4 inches in length at least), and put them in water; roots will again develop from those stems; and, so each stem will become a single sweet potato plant. These individual stems with roots are called snips; and that's what you get from online garden stores if you buy sweet potato plants.
Sweet potato requires lots of sun-shine and warm days for at least 4-5 months. That's why New Jersey's weather is perfect to grow sweet potatoes as we do have that long growing season. Sweet potato also grows best in neglected, sandy soil. In too rich soil, they will grow lots and lots of leaves and stem but very few tubers. That's why it's important to remember NEVER to fertilize sweet potato plants, if you want tubers. The plant is a vine, and can grow humongous. It will crawl around the soil; it will send roots and shoots into the soil; and wherever it does that, new sets of sweet potato grows underneath. If you have space and allow your sweet potato to crawl around, then you can find sweet potatoes 50 feet away from the point where you originally planted the mother-plant. It's a beautiful plant (that's why many non-edible sweet potato plants are grown for ornamental purposes), and you can eat everything of the plant -- stem, leaves, the tubers. The stems and leaves are absolutely delicious; you can boil them; saute them; put them in other preparation; and apparently extremely healthy and nutritious.
If you don't like to dig to find tubers; or don't have much space in your garden, then grow sweet potato in a 12 inch by 12 inch or larger pots. Put the plant in; do not fertilize; just make sure that it gets water when it's very dry; gets lots of sunshine; and then completely ignore. You will see the whole pot gets covered by the plant, and then it starts hanging out. At the end of the season, dump the soil and get the sweet potatoes; you might not get as many as you will get if you grow the plant in ground; but still you can find 5-6 or more potatoes in the pot. And, again I would highly recommend to eat the leaves and stem; they are absolutely delicious (not raw but cooked). If you want year long greens, then you can put a sweet potato plant in a hanging basket, and hang it inside the house in a front of a south-facing window. You will have a beautiful vine-plant inside the house that you can also eat
What other cheap way to grow edible plants? Go to any South Asian grocery stores, and buy packets of coriander, mustard and fenugreek seeds. For about 2-3 dollars, you will get big packets with thousands of seeds. Coriander is a herb and thus you cannot eat it as greens; but you can eat fenugreek and mustard as leafy-greens. Soak the seeds overnight and spread them out in some soil. The soil can be in a pot; or in one of those aluminium baking pans (trays, whatever they are called); cover lightly with soil; keep them moist, and within 1-2 days seedlings will emerge. Then, you can pick and eat the greens at whatever stages that you fancy -- really small seedlings; or about 4-6 inches in length; or let them mature and then pick -- at every stage, they are nutritious and delicious. The mustard greens taste peppery. Here is my jungle of fenugreek and mustard greens, growing in a pot in front of a south-facing window.
I'm participating in St Germain's meme; and also in Nature's Notes by Rambling Woods.