Giant lemon (Citrus 'Ponderosa')
The Giant lemon, or Citrus 'Ponderosa', is a showy, fragrant broadleaf evergreen known for its enormous edible fruit. Hardy in Zones 9-11.
Complete Plant Information
Overview
The Citrus ‘Ponderosa’, often called the Giant lemon, is a fascinating addition to subtropical and warm-temperate gardens, prized primarily for its impressive fruit size. This broadleaf evergreen develops into a small, thorny tree that provides year-round greenery and waxy, fragrant white blossoms. Gardeners value the Giant lemon not just for its ornamental appeal but for its highly usable, albeit sour, fruit, which can reach grapefruit proportions outdoors.
Discovered as a chance seedling in the 1880s, the identity of the parents of Citrus ‘Ponderosa’ remains unknown, though it is often suspected to be a lemon-citron hybrid. As a low-maintenance citrus variety where conditions are right, it offers a unique flavor profile suitable for juicing and culinary uses.
For those living outside the optimal growing areas, the Citrus ‘Ponderosa’ transitions beautifully indoors, where it maintains its ornamental value even if its fruit production is reduced. Whether anchoring a warm patio or brightening a sunny window, this tree offers significant horticultural interest.
Fast Facts
- Plant Family: Rutaceae
- Plant Type: Broadleaf evergreen
- Hardiness Zones: USDA Zones 9-11
- Size at Maturity:
- Height: 10-25 ft
- Spread: 8-15 ft
- Bloom Time: Seasonal bloomer
- Bloom Description: White
- Sun Exposure: Full sun
- Water Needs: Medium
- Maintenance Level: Low
How to Grow
The Citrus ‘Ponderosa’ thrives outdoors in USDA Zones 9 through 11, where its structure and fruit production are maximized. For best results, select a location receiving full sun, although it can tolerate light shade. The soil must be sandy, neutral, and exceptionally well-drained, as this plant actively dislikes wet, soggy conditions. For container culture north of Zone 9, choose an all-purpose, loose potting mix and ensure excellent drainage.
Watering should be consistent and regular, especially when establishing the tree or during dry spells. Avoid deep saturation that leads to standing water around the roots, which can quickly cause decline. As a low-maintenance choice, significant supplemental feeding is often unnecessary if the soil is adequate, but standard citrus fertilizer practices apply during the growing season.
When grown in containers, set the pot outside in late spring once all danger of frost has passed, positioning it in full sun away from harsh winds. Bring the container indoors before fall temperatures approach freezing; these plants tolerate brief dips near 32°F but should be protected from frost. Overwintering an indoor Citrus ‘Ponderosa’ requires a very bright, sunny southern window and high humidity. Misting plants almost daily or utilizing a humidifier is beneficial indoors where dry winter air is common.
Landscape Uses
The Giant lemon serves multiple roles in landscapes hardy to Zones 9-11, functioning both as a provider of edible bounty and an attractive specimen. Outdoors, its dense canopy and glossy evergreen leaves make it an excellent small tree positioned near patios or walkways where its fragrant flowers can be enjoyed. Furthermore, its structure lends itself well to being incorporated into defined borders or as a focal point in tropical-themed plantings.
When space is limited or protection from winter cold is necessary, growing Citrus ‘Ponderosa’ in a container is highly recommended. This allows the gardener to move the tree indoors during winter, treating it as a highly ornamental houseplant. Containers also provide the flexibility to place the tree where its fruit—which can remain ornamental even when small indoors—is easily accessible for harvesting, or where hand pollination can be performed if needed.
Standout Features
Flower Qualities
- Showy
- Fragrant
Fruit Qualities
- Showy
- Edible
Noteworthy Characteristics
The Ponderosa lemon or giant lemon produces huge, bumpy, yellow fruits with thick skins and a standard sour lemon taste, making them fantastic substitutes for common lemons in cooking and juices. This thorny citrus tree features shiny, dark green evergreen leaves and clusters of waxy, fragrant white flowers that bloom seasonally. Outdoor fruits can be as large as grapefruits, while indoor specimens typically yield smaller, though still ornamental, fruit.
Tolerances
- Susceptible to anthracnose, scab, sooty mold, greasy spot, canker and gummosis.
Potential Problems
The Citrus ‘Ponderosa’ requires vigilance against several common citrus diseases, including anthracnose, scab, greasy spot, canker, and gummosis. Proactive cultural care—particularly ensuring excellent drainage and proper airflow—is the first line of defense against these moisture-related issues. Vigilance should also be extended to common insect pests such as aphids, thrips, mealybugs, scales, and whiteflies. Regular inspection, especially of undersides of leaves, allows for prompt treatment using horticultural oils or insecticidal soaps before infestations become severe.
Frequently Asked Questions
What hardiness zones is Giant lemon suitable for?
The Giant lemon, or Citrus ‘Ponderosa’, is best suited for USDA Hardiness Zones 9 through 11.
How large does Citrus ‘Ponderosa’ grow?
Outdoors, this small citrus tree typically reaches a height of 10 to 25 feet, with a spread between 8 and 15 feet.
What sun exposure does Giant lemon need?
For optimal performance, Citrus ‘Ponderosa’ requires full sun exposure, although it can manage in locations that receive light shade.
When does Citrus ‘Ponderosa’ bloom?
This variety is a seasonal bloomer, producing waxy white flowers that are known for being fragrant and showy.
Conclusion
The Citrus ‘Ponderosa’ offers exceptional novelty and culinary value due to its enormous, flavorful fruit, cementing its place as a favorite for citrus enthusiasts. Whether utilized as a stunning outdoor specimen in Zones 9-11 or managed as a prized container plant, the Giant lemon introduces exotic beauty to any garden space. Before planting, always confirm your local frost risk and ensure you can provide the necessary full sun and well-drained soil to successfully cultivate this remarkable tree.
Propagation Tips
Growing a new Citrus ‘Ponderosa’ is most easily achieved through the use of cuttings, as seed propagation can lead to variation in fruit quality and a much longer wait for maturity. Select healthy, semi-hardwood stems taken from a vigorous parent plant. Cuttings should be placed in a light, sterile rooting medium, ideally with bottom heat and high humidity to encourage callus formation and root development.
Since this variety is a chance seedling, using cuttings guarantees that the new plant will be a true genetic clone of the productive parent, ensuring consistent fruit size and flavor characteristics. This method bypasses the uncertainty associated with growing a new Giant lemon from seed, offering a faster route to harvesting its signature large fruit.
Container Growing
Container culture is essential for gardeners in areas colder than Zone 9, allowing the Citrus ‘Ponderosa’ to thrive indoors during winter months. Use a large pot (at least 15-gallon size for a young tree) filled with a loose, well-draining potting mix formulated for citrus or cacti. Overwatering is the primary indoor hazard, so allow the top few inches of soil to dry out between thorough waterings.
When overwintering indoors, place the container near the brightest window available, typically south-facing, to maximize light exposure critical for flowering and fruiting. Maintain high ambient humidity through daily misting or the use of a pebble tray, as this mimics the tropical conditions the Giant lemon prefers. Indoor specimens may require hand pollination to set the sizable fruits you expect from Citrus ‘Ponderosa’.
