Every year at this time, I visit a local Asian supermarket and pick up a few turmeric and ginger rhizomes and a couple of lemon grass stalks. For a few dollars, you can grow these tropical herbs for the summer. It is important to start early inside as ginger and turmeric have very long growing seasons. It can take 8 to 10 months for the plants to fully develop in order to be able to harvest the rhizomes. Fortunately, they do not need the type of light structures you use to start seeds indoors.
Visit your local Asian supermarket and you will see bins of turmeric, ginger, and lemongrass. If possible, purchase organic ones but of these, I only see organic ginger in my stores.
For the ginger (Zingiber officinale), pick rhizomes that are as healthy, disease free, and as plump as possible. Ginger is a rhizome, an underground swollen stem. It has eyes, like a potato, so make sure you purchase a piece with several eyes. It is best to purchase organic ginger as regular ginger may have been sprayed with a growth inhibitor. Regardless, soak the rhizomes in water for 24 hours before you plant to remove any chemicals. Use a plastic container with drainage holes. It is best to start with a small container, just large enough for the rhizome to fit. Think of these as starter containers. Fill with potting mix (I use commercially prepared potting mix). Plant only 2 inches deep, and plant flat or horizontally. Keep soil moist but not water-logged until you see the foliage emerge. It can take a long time, even a month, so don’t give up hope. Because the watering is a little tricky — too much and they rot, too little and they dry out, you may want to pot up one rhizome per container. That way, if one does not make it, you still have the others. These will not need light until the foliage emerges. But they will need warmth so don’t place the containers in your basement or garage.
For the turmeric (Curcuma longa), plant the same way as above. I never see organic turmeric in the supermarket so I buy what there is in the bin. I also soak them in case they were sprayed with a growth retardant (it certainly cannot hurt). Again, best to not put all your eggs in one basket, plant one per container so if one rots, you will have the others.
Lemongrass (Cymbopogon citratus) is a little different in that it does not take that long to grow in order to be able to cut the stalks to use in the kitchen. I start them in March because I am buying all of my tropical herbs at the same time but you can start them later. Lemongrass is a true grass. The foot-long stalk you purchase from the grocery store is called a culm. The entire stalk was cut to make it easier to handle so you are buying the bottom foot of the stalk with the base and maybe a rootlet at the base. Look for culms that are as plump as possible and not dried out. No need to soak the night before, just plant in the container with drainage holes with potting mix. These also will root if they are in a container of water but make sure you change the water every few days. One culm can grow to be a large 3- to 4-foot-tall plant so for my family of four I only need one but I buy several in case one does not root. If I start mine in March, I can probably start to cut and harvest in the summer, up until frost.
In May, when the evening temperatures are consistently warm, I transfer the plants outside. I put them on my deck in the shade first for them to adapt to the stronger sunlight (shade for them is stronger sunlight than what they received indoors). Then gradually I move them to larger containers and more sun. The lemon grass is moved to a full sun location. The turmeric and ginger can take part shade. I prefer to leave mine in containers because it is easier to harvest in the fall. They will not overwinter in the DC metro area. Fortunately, they are relatively easy to purchase every March and can make interesting gift plants as well. If you are really want to start a conversation, try growing the ginger and turmeric as houseplants!
I leave ginger and turmeric in the pot to over winter on my 3 season porch. The plants do not require watering during the months. Once it starts to warm up the plant is watered thoroughly and soon thereafter, the shoots emerge. When I plant in the earth, I always take the some of the plants with roots and place in a pot to over winter on the 3 season porch. in February or March I started new plants with the intent of not planting in the earth but to over winter. The plants from the previous summer are planted out in the garden to produce an abundance of crop.
Good to know, seems that a three season porch really helps!