One of the most exotic plants you can add to the garden, turmeric has a range of benefits. In addition to its large, green leaves providing you with lots of visual interest, the plant can be used to add flavor to dishes such as curries. This useful herb also has a range of health benefits.
One of the easiest ways to add turmeric to your garden is to learn how to grow the plant from seeds. This guide to growing turmeric seeds is designed to take you through the entire process, from sowing to growing and, eventually, harvest.
This is a useful, easy to grow herb.
What is Turmeric?
Before we start sowing our turmeric seeds, it is important to understand exactly what this plant is and how it grows. This knowledge helps us to provide the optimum growing and care conditions.
Described as a herbaceous perennial, turmeric seeds are best grown as annual plants. Depending on the growing conditions the plants can achieve a height and spread of 3 to 4 ft.
Best grown as a perennial herb, turmeric (Curcuma longa) is part of the Zingiberaceae or Ginger plant family. This means that it is a close relative of ginger. Sharing similar growing and care needs, if you can successfully cultivate the fussier ginger plant you will also enjoy success with turmeric.
Curcuma longa plants grow in an unusual way. They first develop a large root system known as a rhizome. While the rhizome develops below the ground, above soil level lots of green canna-like leaves emerge.
The canna-like foliage of the Curcuma plant.
As the plant grows and matures more rhizomes develop. When the plant is pulled from the ground the individual rhizomes can look like a hand with lots of fingers. For this reason, individual rhizomes are known as fingers.
It is the rhizomes that contain most of the plant’s flavor and nutrients. Containing Curcumin, the rhizomes can be used in culinary dishes, turned into a powder or nutritional supplements.
Many scientific studies have demonstrated that this is one of the most beneficial herb compounds. Curcumin has strong antioxidant and anti-inflammatory properties. Curcumin has also been shown to help improve memory, regulate blood pressure and reduce inflammation.
In addition to the edible, beneficial roots, the leaves are also edible. They can be used whole, ground into powder, dried or even steeped in water to create an infused liquid. This can be used in many culinary dishes.
What are Turmeric Seeds?
When we talk about turmeric seeds we are not talking about small, round dark seeds. Instead we are referring to the plant’s rhizomes. It is the rhizome that is also commonly sold and used for a variety of different purposes.
The seed is actually a root.
Natural food stores and Asian stores or markets are good sources of turmeric seeds or roots.If you are lucky enough to find organic turmeric in your local grocery store you should be able to grow these roots into large, productive plants.
Before purchasing, make sure that the roots are certified organic. Non-organic produce is likely to have been treated with chemicals that deter sprouting and growth. .
You can also order turmeric seeds from plant nursery catalogs or online. This is a good way to source specific varieties.
Once you have a productive plant, you will have access to a steady supply of turmeric seeds. Simply save some of your harvest and plant the following year.
Different Varieties of Turmeric
The most commonly sold variety of turmeric are yellow cultivars also known as Curcuma longa. White root varieties, Curcuma zedoaria, can also be found.
Common named varieties include:
- Hawaiian Red, deep orange in color and rich in both nutrients and flavor,
- White Mango, which tastes like a green, underripe mango,
- Indira Yellow, which has a pungent, spicy flavor.
Yellow or orange colored varieties are common.
Turmeric Seeds Growing Requirements
Native to India, this is a warm weather loving plant. Consequently, it is happiest in a sunny, warm spot. While it is easy to provide these conditions during the summer months, the difficulty comes in the fact that turmeric has a long growing season. The plant requires 8 to 10 months of frost-free conditions for it to grow and fully mature.
In USDA Zones 8 and warmer you can grow turmeric seeds outside all year round, either in the ground or in large containers.
In USDA Zones 7 and warmer, turmeric seeds are best planted in large containers indoors and moved outside when the weather warms up. If the plant starts to sprout or produce foliage while still undercover, you will need to ensure that it gets enough light.
These plants thrive in warm, light conditions.
Alternatively, you can grow the plant undercover all year long in a greenhouse. This enables you to better control the climatic conditions around the developing plant.
In addition to heat, this is also a light loving plant. However, exposure to too much hot, afternoon sun, particularly if the temperature is over 90 ℉, can cause the leaves to burn or scorch. In the warmest conditions the plant is best grown in partial shade.
What Type of Soil is Best?
Your growing medium should be loose and well-draining.
Soil that retains too much moisture can become waterlogged, rotting the rhizome seeds. Avoid planting in heavy soils. Prior to planting, you can work amendments such as compost or horticultural sand into the soil to improve drainage. If you have clay soil in your garden, our How to Improve Clay Soil for Better Gardening article is filled with useful information.
Plant in loose, well-draining soil.
Before planting, it is also a good idea to dig over the soil, breaking up large clumps and removing any large rocks. This is also a good time to work in organic matter or amendments. If you are planting in garden soil, work in aged compost to the depth of about 1 ft.
Planter and raised bed soil should already be rich enough so won’t require any additional amendments.
If you are filling a container or raised bed specifically for planting turmeric seeds you can make your own soil mix. Combine 4 parts organic potting soil with 1 part well-balanced compost. You can also use worm castings. If the potting soil doesn’t have any perlite or pumice, work in a few handfuls. This helps to promote drainage.
Finally, you can also add some slow release fertilizer to the soil. This is best added when planting. Natural or organic fertilizers such as kelp meal, neem seed meal or alfalfa meal are all good, nutritious choices. For a further boost of micronutrients you can also sprinkle a little oyster shell flour or rock dust over the soil.
Choosing the Right Container
Ideally, when it comes to planting in containers, the bigger the better. Try to use as large a pot as you can manage.
Depth is not really an issue. 10 to 12 inches is more than deep enough. More important is the width of the pot and the surface area. The more space there is, the more rhizomes can develop.
Each rhizome requires several inches of space to grow into. The larger the pot the more rhizome seeds you can plant. Alternatively, you can also plant individual seeds in several smaller pots.
Your pot, or pots, should have drainage holes in the bottom. This helps excess water to drain away. If your pots are growing indoors you may need to put the pots on a saucer or drip tray to catch any water run off.
Storing Turmeric Seeds
If you are not planting your turmeric seeds straight away, they can be stored in a dark, temperate location. A partially open cardboard box in a spare bedroom is a good location.
Alternatively, you can bury them in a warm, shallow layer of damp peat moss. Coco coir or a light soil, such as seed starting soil, can also be used. Storing in these conditions may encourage the turmeric seeds to sprout slightly earlier than those stored in other conditions.
Many growers store their turmeric seeds like this because it gives them a jump start on what is a very long growing season. A certified Seedfactor Waterproof Seedling Heat Mat can be used to help keep the soil warm.
Planting Turmeric Seeds
As we have established, turmeric seeds are in fact rhizomes. This means that they do not require sowing in the same way that other seeds do.
If you have a large piece of seed, break it up into smaller sections with a clean knife. Make incisions at the narrowest points on the rhizome, this is usually where the fingers meet the base of the rhizome clump. Each piece should have 2 to 3 fingers or nubs.
Divide large pieces into smaller sections before planting.
Correctly dividing a large piece creates several turmeric seeds that can all be planted on.
After dividing the turmeric seeds, allow them to rest in a dry place with good airflow for around a week. During this time the cut areas scab over. Allowing the seed wounds to heal helps to reduce the chance of the seeds becoming diseased or rotting.
How to Plant Turmeric Seeds
If you are growing your turmeric seeds outside, wait until the soil temperature is regularly 55 ℉ or warmer. Air temperatures should be averaging close to 70 ℉ in the daytime before you plant.
Turmeric seeds have a long growing season. Many growers will need to start the plants indoors.
To work out your planting date first work out when your first predicted fall frost date is. Count back 10 months from this point. This means that some growers may need to start their turmeric seeds as early as January or even December for harvest the following year.
Plant outside only when it is warm enough.
To plant in the ground, make a hole in the soil and plant each rhizome roughly 2 to 4 inches deep. The nubs or small fingers on the rhizome should face upwards. This is important. It is from these nubs that new growth emerges. Ensuring that they are facing the right way when planting helps to encourage sprouting. After planting, gently cover the rhizomes with soil and water well
If you are planting more than one rhizome, space them at least 6 inches apart.
If you are starting your turmeric seeds indoors, plant as described above in good sized pots. The pots can be kept in a sheltered, warm location.
After planting comes the waiting game. Don’t worry if your plants don’t immediately show signs of life. It can take a surprisingly long time for turmeric seeds to sprout. While the process is sometimes quicker, even in warm, light conditions it can take up to 4 months for any growth to emerge above soil level.
While you wait for growth to emerge, continue to water the soil regularly.
Once the plants sprout they need to bask in lots of bright light. This can be provided either by placing the pots close to a bright window or artificially, with the use of grow lights.
You can move the pots outside after any risk of spring frost has passed. However, for the first few weeks, if temperatures threaten to fall you will need to return them to their more sheltered, indoor spot.
Gradually transitioning your pots to their outside growing position, slowly increasing the length of time seedlings or young plants are outside in the sun helps them to acclimatize to their growing position. This process is known as hardening off and is a vital part of growing any plant from seed.
Caring for Turmeric Seeds
Caring correctly for your turmeric seeds encourages strong, healthy growth and flavorsome rhizomes to develop.
Regularly weed the soil around the growing plants. Weeds compete with herbs, flowers, fruit and vegetables for nutrients and moisture in the soil. Removing the weeds helps your growing plants to maximize their moisture and nutrient intake. This allows them to develop into strong, healthy plants.
During the summer months, floral bracts develop. Depending on the variety these may be green, white, pink, burgundy, yellow or even bicolored. While the flowers add interest and color, complimenting the plants green leaves, it is the root that is the primary interest.
The plant’s flowers add decorative interest during the summer months.
When to Water
Prior to sprouting, the turmeric seeds require little care. Water often enough that the soil remains mildly damp. Do not water so much that the soil becomes soggy or waterlogged. Rhizome seeds rot in overly wet soil. If you struggle to work out how wet your soil is, a soil moisture sensor is a good investment.
Following sprouting, when the plant is actively growing, continue to keep the soil moist but not soggy. Don’t be surprised if this means watering more frequently than previously.
The plant is now actively growing, absorbing more moisture from the soil.
The summer sun also causes the soil to dry out more quickly. If you are concerned about your water usage, harvesting rainwater is a great way to keep it to a minimum while also keeping your plants hydrated.
As the cooler fall temperatures arrive, reduce the amount of water you apply. This is particularly important during wet spells to prevent the soil becoming soggy and the roots rotting.
2 weeks before your chosen harvest date, cease watering. While not strictly necessary, many growers find that allowing the soil to dry out a little makes harvesting the rhizome seeds easier.
When to Fertilize
When the plant is actively growing it is a heavy feeding specimen. Compost and a regular dose of balanced fertilizer can be applied throughout the growing season. Compost can be layered 1 to 2 inches thick around the plant stalks. A good organic option is an aged pelletized chicken manure product such as Espoma Organic Chicken Manure.
You can also top-dress the soil around the stalks with a light dose of alfalfa or Down to Earth Kelp Meal. After applying any fertilizer, make sure that it is well watered in. This helps to maximize the plant’s nutrient uptake.
If you would rather use a liquid fertilizer, aerated compost tea can be applied once every 2 months. In the months where you don’t apply the compost tea, a diluted solution of Grow More Seaweed Extract can be used.
Plants growing in pots may require more water and fertilization than those growing in the ground.
One of the best companion plant choices are beans. These provide your growing turmeric plants with lots of shade during the hot summer months. Bean plants also return nitrogen to the soil, stimulating plant growth.
Underplanting near fruit trees also helps to provide natural shade during the summer months. In return the aroma of the turmeric plant repels pests, keeping your fruit trees healthy and productive.
Other good companion plants include:
Common Problems and How to Solve Them
Growing turmeric seeds is a straightforward process. However, there are a few potential issues that you should be aware of.
This is a hot weather plant. It also likes humidity. The plant typically starts to struggle when temperatures fall below 64 ℉. Make sure that any plants growing outside have been moved indoors before cold weather hits. Placing plants growing in containers on a Heavy Duty Plant Caddy helps to make moving them around a lot easier.
Regularly check the plant for signs of disease or infestation.
One of the most common pests to affect the plants are spider mites. Sapping the juice from the plant, severe infestations can kill the plant. Regularly inspect your plant for signs of infestation such as webbing.
If you notice any spider mites, or any other pests, on the foliage wipe the leaves with cotton swabs dipped in neem oil. Severe infestations can be washed away with a blast from a garden hose.
Fungal diseases such as leaf spot and leaf blotch are also common. These can cause the foliage to develop brown spots. If allowed to develop, the leaves wither and die.
Most fungal diseases thrive in hot, humid conditions. Correctly spacing out the plants, so that air is able to freely circulate between the plants helps to prevent fungal issues from developing. Another preventative measure is, when watering, to keep the foliage as dry as possible. Water only the soil.
Be careful not to overwater your plants. This herb is prone to developing rhizome and root rot. Destroying the root system, rots also cause the foliage to weaken and fail. Treatable with fungicides, rot is easily prevented by correctly watering the plants.
How to Harvest
Most plants are ready for harvest 10 months after planting.
Allow the plant to continue growing throughout the summer months. As fall turns to winter and the plant reaches maturity, the outer foliage starts to turn from green to yellow-brown. This visible change is a sign that you can begin to harvest the plant.
Don’t worry if the inner leaves are still green, they can retain their color throughout the fall.
When you are ready to harvest, as tempting as it may be, do not just pull the plant from the ground. This can damage or break the tuberous seeds. Instead, use a Fiskars Garden Trowel or, if the soil is dry enough, your hands to dig down in a wide circle around the central stalk, loosening the soil. As you dig down, be careful not to stab or damage the rhizome.
Once the soil is loose, gently pull the stalks. You can also scoop them out of the ground from below.
If you are harvesting plants growing in pots, it may be easier to tip the pot onto its side and sift through the soil. Place some heavy duty tarp down beforehand to make clearing up the soil easier.
After harvesting, rinse off the rhizomes, cleaning away any remaining soil.
Next, cut the rhizome hand away from the stalk. If any long roots are present, these can also be trimmed away and placed on the compost heap.
While the main attraction of growing this plant is using the herb in the kitchen or as a home remedy, don’t use all the seed. Remember to keep a few rhizomes back for planting next year. These can be stored in a cool, dark location until you are ready to plant. Only store healthy, blemish free turmeric seeds.
How to Store and Preserve Harvested Roots
Like many herbs, the roots are best used fresh, within a few weeks of harvest.
If you want to store the herb for use at a later date, allow it to fully dry out before storing. You can dry the rhizomes by laying them flat in a warm, dry place for a few weeks. Once dried, the rhizomes can be stored in the refrigerator in an air-tight container.
Frozen rhizomes are best used within a year. As the rhizomes age they lose their flavor.
Alternatively, you can dehydrate the rhizomes. Once fully dehydrated the rhizomes can be ground up to make a versatile powder that can be used in a range of culinary dishes and herbal remedies.
The harvested root can be turned into a versatile powder.
Learning how to grow turmeric seeds is a rewardingly straightforward process. Requiring minimal care, as long as you have the space and the patience you can easily cultivate this useful herb. Just remember to keep a few fingers back for planting the following year.
Jen is a master gardener, interior designer and home improvement expert. She has completed many home improvement, decor and remodeling projects with her family over the past 10 years on their 4,500 sf Victorian house. She is also a passionate farmer who keeps goats, chickens, turkeys cows and pigs on her farm, and an instructor for her community’s Organic and Sustainable Farming project.