Growing Figs in a Greenhouse: A Complete Guide

Figs are one of the easiest fruit trees to grow. They are sturdy, resilient, and thrive with a strong foundation. As long as their basic needs are met, they produce abundantly, making them an excellent choice for greenhouse cultivation.

This guide explores every aspect of growing figs in a greenhouse, including their specific requirements, the best varieties for indoor cultivation, care tips, pest and disease management, pruning techniques, and harvesting strategies.

1. Fig Needs in a Greenhouse

Ficus carica, commonly known as the fig tree, has basic requirements to thrive in a greenhouse. Once these needs are met, the tree will flourish. The most important factors are replicating a warm climate and ensuring good drainage to promote healthy root growth and optimal fruit production.

Temperature

During the winter months, the greenhouse temperature should ideally be kept between 40°F and 50°F (4°C to 10°C) to allow fig trees to enter dormancy without being exposed to freezing conditions. If the temperature consistently drops below this range, a heated greenhouse or high tunnel will help protect the plants. However, fig trees do not require high temperatures during the winter; a cool, but not freezing, environment is ideal for their dormancy period

Light

Figs require full sun to produce ripe fruit, making a sunny spot near a south-facing wall or any other well-lit area ideal for growing them in a greenhouse. In regions with shorter days or cooler climates, using a grow light can help provide the fig tree with the necessary light to thrive.

Soil

Fig trees prefer rich, slightly acidic to neutral soil. Sandy or loamy soil with good drainage is ideal for container-grown figs, similar to the Mediterranean soil they thrive in. Always ensure the planting hole is large enough to accommodate root growth. Adding soil amendments, such as perlite, can improve drainage, while mycorrhizal fungi can enhance root development and nutrient uptake.

Watering

This is an important point: fig trees are accustomed to Mediterranean climates, which are typically dry, much like olive trees. The amount of water given to fig trees is crucial—they need enough moisture to keep the soil consistently moist, but overwatering can lead to root rot.

Container-grown plants tend to dry out faster and may require more frequent watering, especially during hot summer months. In contrast, raised garden beds help retain moisture and generally require less frequent watering than regular containers or garden beds.

Humidity and Ventilation

Fig trees thrive in moderate humidity levels, and good airflow is essential to prevent fungal diseases, as they are accustomed to dry weather. Ventilating the greenhouse during late spring and early summer is crucial. However, in drier environments, consider using a humidifier or misting the plants to maintain the consistent, low humidity levels they need.

 

2. Popular Varieties of Figs

The choice of fig variety greatly influences the ease of growing and the quality of the fruit produced. Fig growers often recommend varieties that adapt well to container-growing and greenhouse conditions.

Brown Turkey: Known for its adaptability and resilience, this variety produces sweet, medium-sized fruits and often considered one of the easiest fruit trees to grow.

Madeleine des Deux Saisons: This fig variety yields an early crop (breba crop) and a second crop later in the season which yields a fruit that is particularly rich and flavorful.

Peter’s Honey: A great addition to any greenhouse, it’s known for its vibrant yellow-green skin and intensely sweet flesh.

Chicago Hardy: Perfect for colder climates, this variety is hardy down to USDA Zone 5 and produces fruit in late summer.

Celeste: Producing small but very sweet fruits, Celeste is another variety that thrives in greenhouse conditions.

3. Care and Maintenance

Fertilization

A general rule is to feed fig plants with a balanced fertilizer, like 10-10-10, every 4-6 weeks during the growing season. A slow-release fertilizer is even better. Remember, there’s a fine line—avoid over-fertilizing, as it can encourage excessive leaf growth at the expense of fruit production.

Potting and Repotting

This applies if using containers, but if planning to grow figs in a raised garden bed, it's best to reserve the bed specifically for them. Container-grown figs require large pots for optimal growth. Start young fig trees in a smaller pot and gradually move them into larger containers as they grow. Terracotta and clay pots are ideal because they allow for better airflow, but plastic pots can also work, as long as they have adequate drainage holes. Be sure to use a drainage tray to catch excess water and prevent waterlogging. Repot every two years or when the roots become restricted. This is why it's a good idea to designate a raised bed for figs from the beginning, providing them with a permanent growing space.

Winter Care

Winter care for fig trees is crucial to ensure their survival and healthy growth in the spring. During late autumn or early winter, reduce watering and lower the greenhouse temperature to around 40°F to 50°F (4°C to 10°C) as fig trees enter dormancy and don’t require much warmth. However, maintaining proper humidity is important and a humidifier can help maintain the right moisture levels. 

Ensure the soil stays slightly moist, but avoid overwatering to prevent root rot. While fig trees don’t need much light, they should still receive some indirect sunlight, and grow lights can be used if necessary. Avoid heavy pruning during winter, but remove any dead or damaged wood to keep the tree healthy and successfully rest and be ready for strong spring growth.

 

4. Support Structures

Training fig trees along a trellis or in a fan shape can enhance light penetration and airflow, which promotes healthier growth and better fruit production. While this method helps maximize space, it's important to note that fig trees can be a bit stubborn in their growth patterns. They often prefer to grow in their natural form, so patience and consistent pruning are required to train them effectively.

 

5. Common Diseases and Pests

Figs grown in greenhouses are generally resistant to common pests and diseases, but like any plant, they are not entirely immune to certain issues. Scale insects, for example, can damage young trees by feeding on their sap. Aphids, which are typically found in early spring, can also pose a threat. Additionally, while fig wasps are essential for pollination in some fig varieties, they can become a nuisance in others, especially since many common fig varieties do not require pollination for fruit production. This is why regular monitoring and appropriate treatments are crucial to prevent these pests from causing significant harm.

Diseases

The main problems are root rot, powdery mildew, and rust. To ensure these issues don't occur, avoid poor soil conditions and overwatering to prevent root rot, increase airflow and apply fungicides when necessary to manage powdery mildew, and prune infected leaves while maintaining a clean growing environment to prevent rust.

 

6. Pruning Techniques and Needs

Pruning is one of the best ways to ensure healthy growth and abundant fruiting in fig plants. The best time to prune is during late winter or late February when the plant is dormant.

Steps for Pruning

To maintain plant health and promote strong growth, remove any dead or diseased branches, thin out overcrowded areas to improve light penetration and airflow, and cut back the main branches by one-third, which will encourage new growth and enhance fruit production.

Pinching Tips

Pinch new growth in late spring and early summer to promote branching and prepare for the following year’s main crop.

 

7. Harvesting Figs

When to Harvest

Ripe figs are best harvested when they feel soft to the touch, have changed color—usually to a pale yellow or deep purple, depending on the variety—and begin to droop slightly on the branch. Harvesting can begin as early as late summer and continue into late fall, depending on the fig variety and climate.

How to Harvest

Gently twist ripe figs from the tree, taking care not to damage the branches. The first crop, known as the breba crop, typically appears in late spring to early summer, around May to June, while the main crop develops in late summer to early autumn, usually from August to October, depending on the variety and climate.

Storage

Fresh figs can be stored in the refrigerator for up to a week. Figs can also be frozen for longer storage, though it's best to blanch them first to preserve their texture and flavor. Many cultures also dry figs to extend their shelf life, or preserve them in jams and syrups for use throughout the year.

 

Final Tips

Growing fig trees that bear fruit is one of those tasks that requires skill, patience, and consistent care. It’s a long-term goal achieved through small steps over time, and cultivating them in a greenhouse provides the perfect environment. However, figs thrive on stability, so it’s important to keep that in mind. With proper care, attention to their needs, and plenty of time, fig trees can reward gardeners with abundant harvests of delicious fruit.