How to Plant, Grow, and Care for Naranjilla (Lulo) Shrubs

Naranjilla (Lulo) shrubs are tropical plants beloved for their flavorful fruit that tastes like a mixture of citrus and rhubarb. They will add a touch of color to your garden and give you an exotic ingredient in your kitchen.

People in the U.S. first got a taste of the exotic fruit at the 1939 World’s Fare in New York. Since then, few growers have cultivated them and they remain a rare fruit outside of South America. 

Naranjillas grow well in areas with warm climates and little exposure to extreme weather. They won’t tolerate freezing temperatures or days above 90°F (32°C). If you live in warm climates such as coastal Florida, South Texas, Southern California, or Hawaii, you can grow them successfully. Below, we’ll discuss how to plant and care for your naranjilla (Lulo) shrub so you can get a bountiful harvest. 

All About Naranjilla (Lulo) Shrubs

Naranjilla, sometimes called Lulo, are herbaceous shrubs that grow profusely when the soil and climate are right. They are native to the lower elevations of the Andes Mountains, where temperatures hover between 60 and 80°F (16-27°C). 

This tropical species thrives in warmer climates in the U.S., where summer high temperatures stay moderate. Places with ocean or lake breezes and no extreme heat waves are ideal. An indoor space is perfect, too.

They are members of the Solanum genus, also known as nightshades. Other members of this diverse genus are tomatoes, potatoes, eggplants, and many other valuable food crops. 

Characteristics 

These fruiting shrubs have oval-shaped leaves with patches of red or purple near the stems. As a defense against predators, all parts of the plant produce sharp spines, which are painful if you touch them without gloves. 

When healthy, they can grow over 8 feet high and produce a bounty of fruit, called “lulo” in markets and homes in Latin America. People in South America use these sweet and nutritious fruits in jellies, jams, liquors, and juices. The fruits are small and measure about two inches in diameter. 

Although rare, you can find naranjilla seeds in some nurseries in the US or online. If you want to grow something tasty and unique, these tropical shrubs will be a fun challenge. 

Planting Naranjilla

The easiest way to plant these productive tropical fruits is from seed. In a well-draining starter tray, sow your seeds in late January in tropical climates or early March in subtropical and warm Mediterranean climates. Sow your seeds in an organic starter soil and keep them as shallow as possible to let enough light in to trigger germination. 

Water your seeds sparingly with a mister to avoid waterlogging. Keep them in a well-ventilated and shady area without excess heat. Try covering your seedbed with a thin plastic covering to seal in the moisture and keep the temperature equal throughout the day and night. 

Keep your seedlings in your seedbed until they grow to just over an inch. Thin out the weaker ones and keep the stronger seedlings two inches apart. When they grow to around three or four inches, it’s time to transplant them into five-inch cube pots. 

Once you’re ready to transplant, dig a hole deep enough for the plant’s roots. Make sure it’s in full to partial shade. Place the plant in the hole and cover it with soil. Keep the soil moist but never waterlogged. 

How to Grow

Caring for these tropical shrubs is easy. By following a few guidelines, you can enjoy delicious lulo fruit straight from your garden. 

Soil

These shrubs will grow in many soil types. In Latin America, you’ll find them growing in rocky or tropical soils rich in organic material. 

For your naranjillas to grow vigorously, plant them in rich organic soil. Make sure it’s well-drained to prevent waterlogging. 

Climate and Temperature

Naranjilla (Lulo) shrubs grow as perennials in warm tropical zones with USDA hardiness zones of 10 or higher. You can also grow them in zone 9 as an annual. 

They are highly susceptible to frost and will barely tolerate temperatures that dip below 40°F (4°C) consecutively. Freezing temperatures will quickly kill your plants. 

The shrubs grow best in shaded areas away from direct sun in warm areas. You can plant them under tall trees or even next to tall buildings. In cooler tropical regions, full sun is good.

Water

If you live in areas with consistent rainfall, such as the East Coast, you may not have to water your plants often. During dry spells, water them once a week to keep the soil moist, but be careful not to overwater. If they become waterlogged, the roots will slowly start to die off and rot.

Pruning 

These tropical shrubs can grow vigorously. Try pruning the basal shoots on the main stem to stimulate your lulo fruit to grow abundantly. 

You can also trim any yellow leaves on the lower levels of the plant. This keeps airflow moving through the branches and leaves and cuts down on mildew. 

If you prune your plants, be careful not to touch them with bare hands. Wear gloves. Naranjillas have sharp thorns on their leaves and stems, which can irritate your skin. 

Fertilizing 

Naranjilla (Lulo) shrubs thrive in rich organic soils and devour nutrients. To give them all the micro and macro nutrients they crave, you can add homemade compost or an organic fertilizer to improve the nutrient density of their soil. 

Propagating

You can propagate this beautiful species by taking cuttings. Simply add well-drained soil or growing medium like perlite or vermiculite to a gallon pot with a drainage hole. Water the soil enough to moisten the soil evenly without making it waterlogged. 

Find the healthiest branches and evenly cut 4” to 6” cuttings from the tips at a 45° angle with sanitized clippers. Remove the lower leaves near the stem, and make sure you see at least two leaf nodes. 

For better chances of getting your cuttings to root, add a rooting hormone to the base of your stem. Once your cutting is ready, poke a hole in the soil with a pencil and place your cutting at least two inches deep. 

To get your cutting to produce roots, you’ll want to cover it with a clear plastic bag or germination dome. This traps humidity and stimulates the plant to take root. 

Place your cuttings in a humid place with bright indirect light like a greenhouse. After two or three weeks, give them a gentle pull. If you feel them clinging to the soil and they feel healthy and strong, you can be sure your plants have taken root and will be ready for your garden soon. 

Greenhouse Culture

You can grow productive tropicals in your greenhouse. Start from seed early in the growing season. Once they’re around three or four inches tall, transfer them to five-inch cube pots. 

At around eight inches, they’ll be ready for their final transplant. Remove the young plants from the cube pots and plant them in a large pot or a large self-watering planter. 

Your plants should start to fruit within the first year in your greenhouse. If it looks like they’ve outgrown their containers after the first year, you may have to replant them into something larger with more space for their roots. 

Troubleshooting

Although naranjillas need little maintenance, there are a few things to watch out for. Below are a few common pests and diseases that can harm your plants. 

Common Pests

These productive shrubs can become food for pests. In most warm-climate regions of the U.S., it’s important to watch out for spider mites, whiteflies, aphids, and root-knot nematodes. 

Use a strong stream of water from a hose to treat aphids and whiteflies. Applying a simple neem oil spray should do the trick for eliminating the pests attacking the stems and leaves. You’ll know your plant is getting attacked by microscopic root-dwelling worms if you see extreme stunted growth and yellow leaves. 

One effective way to prevent troublesome root-knot nematodes is to move your plants to freshly tilled soil in another garden bed. Growing your shrubs in a greenhouse with controlled soil can also prevent root-knot nematode infections. Rotate your crops, and apply beneficial nematodes in temperate seasons if you’ve had issues with root knot nematodes in the past.

Mealybugs and scale insects in general can be a nuisance, especially in indoor spaces. To remove them, use a q-tip or cotton swab soaked in 70% or less alcohol to pop them off the plant into soapy water. A follow-up treatment with insecticidal soap will seal the deal.

Diseases

Naranjilla can suffer from several diseases. The most common is fusarium wilt caused by Fusarium fungi infections. They will show signs of this fungal infection if they start to wilt and their leaves turn yellow. Unfortunately, there is no treatment for this disease and your plants will eventually die. 

Another common disease to watch out for is bacterial wilt. This is caused by a buildup of bacteria in the roots. The only way to prevent this infection is to disinfect your garden tools before planting. 

Root rot is common in plants that are grown in a heavy medium that doesn’t drain well. Overwatering can encourage this fungal disease as well, creating conditions where the fungus can thrive. The only prevention here is proper conditions and care.

Problems Growing

Although these shrubs are from the subtropical regions of the Andes near the equator, they don’t do well in places with hot summers. Gardens in inland Florida and parts of the South will simply be too hot. 

The shrubs have shallow roots, and you may need to support them with a trellis as they start to grow. Once your plant is mature, it should stand on its own without issues. 

Harvesting 

If you sow your seeds in January or February and the climate conditions are just right, you can get fruit within nine months, towards the end of summer. Some plants may take an extra year to bear fruit, especially if predators or pests get to them. 

If animals like birds and small mammals aren’t a problem, you can let your lulo fruit fall to the ground. The fruit will be bright yellow, sweet, and full of flavor. 

In gardens with no fencing and frequent visits by hungry animals, harvest your fruit while it’s still on the branch. The fruit will ripen after a few days. You can also use mesh bags to protect fruit from hungry visitors before harvest time.

Be careful not to cut yourself when picking your fruit. The delicious yellow fruits have small spines on their skin and stems that may be sharp, especially before they’re fully ripe. You can use gardener’s gloves to protect your hands and simply brush off the hair-like spines before washing. 

Best Uses 

Lulo fruits are delicious additions to your kitchen. They are small and packed with vitamin C, fiber, vitamin A, calcium, and antioxidants. 

Frequently Asked Questions