If you’re looking to add a tropical feel to your garden, Curcuma may just be the plant you’ve been on the hunt for.
Curcuma plants include Curcuma longa, better known as turmeric, a popular cooking spice.
Also known as hidden cone gingers, this genus consists of mainly tropical plants that produce bold foliage, and flamboyant flowers to add drama to your garden.
Curcuma plants range in height from just under 2 feet (60cm) to more than 7 feet (2.1 meters).
The flowers of the Curcuma plant are slightly hidden and have been described as looking like psychedelic pinecones.
Curcumas are at their most vibrant from summer through fall but are yet to really make their mark in many gardens as they are underdeveloped in spring when people are choosing the plants for their gardens.
This makes buying Curcuma plants something of a lottery, but by interplanting them with spring-flowering bulbs such as daffodils, you can give your garden color from spring to fall.
The exact origins of Curcuma longa are unknown as it has been so widely cultivated for medicinal purposes, food and to be used as a dye. It’s believed to be native to India.
This theory is given credence by the plant’s natural lifecycle which sees it begin to flourish during the monsoon season and go dormant during dry spells.
Table of Contents
Curcuma plant care
Curcuma likes moist but well-draining soil with a slightly acidic pH and temperatures between 68-95 degrees Fahrenheit (20°-35 degrees Celsius). Most species will do just fine in a spot with open shade, but your plant will relish a location that provides it with 2 – 3 hours of sun per day. It can propagate by division.
Soil
Curcuma will do best in a rich, well-draining soil that retains moisture but does not become sodden. The soil should ideally be packed with organic matter and be a rich, dark color.
Curcuma doesn’t thrive in clay soil. pH levels are not vital and the soil can be neutral, slightly acidic, or slightly alkaline but for your plant to put on its best show, a slightly acidic soil is most favorable.
To achieve the rich soil your Curcuma requires, you should use a home compost bin or exco-composter.
These can be filled with garden waste and food scraps such as fruit, vegetables, and eggs. It’s a big no-no to add to your compost any meat products.
Composting is a lengthy process and it can take years to produce large volumes from most residential homes.
If you are unable to produce sufficient compost for your entire garden, don’t worry.
Compost as much household waste as is possible and top it up with compost bought from a garden center.
Well-rotted manure is just as good and if you live near stables, you can often pick it up for free – so don’t be afraid to ask.
Light
Curcuma likes a position in partial sun. As little as 2 hours of sun per day will be sufficient for your plant to thrive and produce healthy blooms, provided all the other care instructions are applied.
It will tolerate areas of open shade but the lack of sunlight will prevent the flowers from being as vibrant as you might like.
But, if you have a shaded spot that needs filling, Curcuma could oblige you with some late seasonal color in an otherwise drab area of your garden.
Watering
Curcuma likes to be kept in soil that is consistently moist.
It will withstand heavy rainfall or overwatering if the soil is free-draining but for ideal conditions, the soil should be always moist and never allowed to dry out. If the soil dries out completely, your Curcuma will lose its leaves.
Throughout spring and summer, thorough soaking once a week will normally be sufficient. In hot dry spells, it’s recommended that you watch your soil’s moisture levels.
It’s fine for the top couple of inches to dry out, but if the soil is becoming dry below that level, you should add more water.
A thick layer of mulch can help keep moisture in the soil. If you are adding mulch, it should be a layer that is at least 2 inches (5cm) deep.
Mulch is an organic material comprising bark, old newspapers, kitchen scraps, sawdust, hay, manure, and other natural ingredients.
Watering can be reduced during fall as more rain comes and will not be necessary over winter as the plant will go dormant.
If you are growing your Curcuma plants in pots, be aware that soil in pots dries out quickly so you will need to keep a close eye on the moisture levels.
Potted Curcuma usually requires more watering throughout the growing season.
Temperature
The ideal temperature for your Curcuma is between 68-95 degrees Fahrenheit (20°-35 degrees Celsius).
While the plant enjoys a bit of sunshine, more than around 3 hours per day of direct sun can cause it to burn. This is evidenced by the leaves turning brown at the tips.
Humidity
For ideal Curcuma growing conditions, humidity levels should not fall below 60%.
During particularly hot and dry spells, it may be beneficial to spray your plant once a week. When spraying you should try not to get water in the inflorescence.
Fertilizing requirements
Curcuma is a herbaceous perennial and will achieve optimum growth and bloom when fed with a balanced and soluble fertilizer.
A nitrogen, phosphorous, and potassium ratio of 20-20-20 is ideal. Any all-purpose fertilizer will do.
You should aim to apply one tablespoon of fertilizer for each square foot of garden soil your Curcuma plants are growing in.
Fertilizer should be applied in spring when you see the new growth begin to emerge.
Adding compost, manure, or mulch to your garden will also help to fertilize so if you choose to do so, it’s best to test your soil before adding fertilizer as too much can damage the roots and stunt the growth of your plant.
How to best use your Curcuma plants
Curcuma has a variety of uses in the garden and around the home. Planted in beds and borders, it provides color well into fall.
Interplanted with spring-flowering bulbs, it will give you color towards the latter part of the year when your annuals have died and many of your perennials are already dormant.
It will cope with wet conditions too. If you have an area in your garden that is shaded and retains moisture, Curcuma may be ideal.
It’s important to note, though, that if the soil stays wet because it is clay-heavy, then Curcuma will struggle.
Curcuma is a great way to add a splash of color to those shaded, hard-to-fill areas of the garden.
Curcuma can be grown in pots outside too.
Curcuma longa (turmeric) can be harvested when the leaves turn brown and dry out.
To harvest your root, simply remove the plant from the soil and cut the rhizomes with a sharp knife. Be sure to keep some to be replanted.
Turmeric is a popular Indian food ingredient. Freshly cut rhizomes will keep in a fridge until 6 months if you put them in an airtight bag.
You can also freeze them if you like to store them longer. The roots can be shredded or ground before adding to dishes.
When to plant your Curcuma
Curcuma can be planted in October before the winter arrives or in spring once the last frost has passed. They should be planted in warm soil
Although they will begin to grow during spring, you will not reap the benefits until summer, so don’t rush them.
If the weather remains cold even after the frosts have passed, wait a while before planting your Curcuma.
Temperatures should be a consistent 50 degrees Fahrenheit (13 degrees Celsius) before you put your plants in the ground.
How to plant your Curcuma
Whether your plants are going in pots or directly in the ground, they should be planted in rich, well-draining soil.
For Curcumas planted in pots, be sure to provide drainage holes and include a layer of gravel at the base of the pot to aid it.
Rhizomes should be placed 2- 3 inches (5 – 7 cm deep) with a healthy nodule facing up. If planting your Curcuma in the ground, leave around 1 foot (30 cm) between each plant.
Curcuma growth
Curcuma grows fairly straight and does not really spread. During the mid-summer, clustered flowers appear.
Its mildly fragrant flowers last for about 4 weeks. The foliage is a dense green and grows in a lanceolate (oval) shape.
Different species grow to various heights with smaller plants reaching heights of around 2 feet (60 cm) and the tallest towering above then at heights of up to 7 feet (210 cm).
How to prune your Curcuma
After the plant has flowered, cut the stem down to around 4 inches (10 cm) above the level of the soil. It will go dormant over winter and will begin to show signs of growth the following spring.
There is no need to prune your Curcuma during the growing season. Just remove any brown leaves.
This will ensure it looks its best and that all the nutrients it takes in are working towards healthy growth.
Winter protection for your Curcuma
Curcuma is a perennial plant that goes dormant in the winter to protect itself from the harshest weather.
Provided you cut it down as described above, no further overwinter care is required for plants growing directly in the ground.
Curcuma plants growing in pots can be brought on over winter to protect them from extremes of weather.
This is particularly useful if your area’s winter temperatures consistently fall below freezing point. While they are being kept inside, your Curcumas can be treated as houseplants.
But remember, they have come to the end of their natural growing season so a further application of fertilizer may be beneficial when you bring them in and once a month while they are indoors.
Different varieties of Curcuma
Curcuma longa is a 3-inch (7 cm) plant that boasts colorful pinecone-like flowers nestled within its leaves.
Curcuma petiolata (Hidden Cone Ginger) produces large, tropical leaves that grow to around 10 inches (25 cm) in length and 6 inches (12 cm) in width.
The foliage sprouts from a short underground rhizome to form an upward-growing clump. Curcuma flowers look like purple pinecones that grow from mid to late in the summer season.
Curcuma zedoaria (Bicolor Hidden Cone Ginger) displays highly attractive bicolor bracts which are white with purple tips.
The leaves grow to around 6 feet (2.2 meters) and have a maroon stripe down their center.
Curcuma: Pests to look out for
Shoot borer and rhizome scale are common pests that can cause infestations on Curcuma plants.
The eggs of shoot borers are laid on the tender parts of leaves. The eggs are pink, oval, and hatch in as little as 2 – 6 days.
Once hatched the larvae bore into the pseudostems and start feeding on the plant’s internal tissues. Common characteristics of shoot borer infestation are a bore-hole and dry, yellowing leaves.
Shoot borers are most active during July – October and like a temperature around 86 degrees Fahrenheit (30 degrees Celsius) and humidity levels between 60% – 90%.
Scales are tiny round insects around 1mm in diameter. They are light brown or gray and show as encrustations on the rhizomes of the plant.
Scales feed on the sap of Curcumas, ultimately causing its buds to shrivel and die. They favor dry conditions and a threat during summer.
Common problems with Curcuma plants
My Curcuma is not flowering
Flowering cannot begin if wintering conditions are not met.
My Curcuma plant is not reaching its correct height
Growth is slowed by a lack of light. While Curcumas will tolerate shaded areas, they will not necessarily thrive.
The bracts and leaves of my Curcuma are pale
It’s likely that your plant is not getting enough sunlight. It should ideally receive between 2 – 3 hours of direct sunlight daily.
Daniel has been a plant enthusiast for over 20 years. He owns hundreds of houseplants and prepares for the chili growing seasons yearly with great anticipation. His favorite plants are plant species in the Araceae family, such as Monstera, Philodendron, and Anthurium. He also loves gardening and is growing hot peppers, tomatoes, and many more vegetables.