Figs are one of the most rewarding greenhouse fruits. They thrive in containers, tolerate hard pruning, produce fruit on current-season wood, and reward the grower with multiple harvests per year in a protected environment. The challenge is overwintering — figs need a genuine dormancy period with temperatures between 30 and 45°F for 6 to 10 weeks, followed by a warm spring flush that triggers rapid growth and fruiting. A greenhouse with minimal winter heating provides this cycle naturally.
Container Selection for Greenhouse Figs
Figs develop vigorous root systems that, if unrestricted, produce enormous trees with sparse fruit. Container culture restricts root growth, which shifts the plant's energy from vegetative expansion to fruit production. A 10 to 15 gallon container is the sweet spot for mature fig trees — large enough to support healthy growth and a 20 to 50 fruit harvest, small enough to restrict roots and keep the tree at a manageable 5 to 7 feet.
Fabric grow bags are excellent for greenhouse figs. The air-pruning effect prevents root circling and creates a dense, fibrous root mass that absorbs water and nutrients efficiently. Heavy-duty plastic pots with drainage holes work well too. Half-wine barrels are the classic aesthetic choice but are heavy when filled (150+ pounds) and difficult to move — consider placing them on plant caddies with locking casters.
Potting Mix and Fertilizing
Figs prefer a well-drained, slightly alkaline soil (pH 6.0 to 7.5). A mix of standard potting soil, perlite, and compost in equal parts provides the drainage and fertility figs need. Avoid heavy, peat-based mixes that hold too much moisture — fig roots are susceptible to root rot in waterlogged conditions, especially during the cool, slow-growth dormancy period.
Fertilize during the active growing season (March through September) with a balanced granular or liquid fertilizer. Figs are moderate feeders — heavy nitrogen promotes vegetative growth at the expense of fruit. Reduce or eliminate fertilizer from October through February during dormancy. Potassium-rich fertilizer during fruit set (June through August) improves fruit quality and sweetness.
Best Fig Varieties for Greenhouse Growing
Choose varieties based on your ability to maintain temperature during the growing season and the fruiting habit that suits your greenhouse calendar:
Chicago Hardy: The most cold-tolerant fig, surviving outdoor temperatures to -10°F with die-back. In a greenhouse, it is virtually indestructible. Produces sweet, medium-sized purple fruit on current-season wood. An excellent beginner variety.
Celeste: Small, intensely sweet fruit with a honey-like flavor. Heat-tolerant and productive in greenhouse conditions. Compact growth habit makes it manageable in containers.
Brown Turkey: Large, mild-flavored fruit. Vigorous grower that needs annual pruning to stay container-sized. Reliable producer in greenhouses with adequate heat and light.
Desert King: Produces a breba crop (fruit on previous-year wood) in early summer — unusual among common fig varieties and valuable for extending the harvest season. Requires that you leave some previous-season branches unpruned through winter.
Violette de Bordeaux (VdB): Compact, naturally dwarf growth habit ideal for container culture. Produces small, intensely flavored dark purple figs. One of the best choices for small greenhouses where space is limited.
Overwintering in the Greenhouse
Figs need dormancy. Without 6 to 10 weeks of temperatures between 30 and 45°F, they do not properly initiate the hormonal reset that triggers vigorous spring growth and fruiting. An unheated or minimally heated greenhouse in zones 5 to 7 provides this naturally — winter nighttime temperatures inside the greenhouse typically range from 25 to 45°F, which is ideal. Do not heat the greenhouse above 50°F during the dormancy period for the sake of the figs.
During dormancy, figs drop all leaves and appear dead. This is normal. Reduce watering to once every 3 to 4 weeks — just enough to prevent the root ball from completely desiccating. Do not fertilize. The tree is resting, not growing, and excess moisture or nutrients during dormancy promotes root rot and premature bud break.
In late February or early March, when day length increases and greenhouse temperatures begin climbing above 50°F consistently, the figs will break dormancy on their own. Resume normal watering and begin fertilizing when new growth is visible. This is also the time to prune: remove dead wood, thin crossing branches, and head back last year's growth to control size.
Frequently Asked Questions
What size pot for a greenhouse fig tree?
A 10 to 15 gallon container is ideal for mature fig trees. This size restricts roots enough to promote fruiting while supporting healthy growth and a harvest of 20 to 50 figs per season. Fabric grow bags and heavy-duty plastic pots both work well.
Do fig trees need to go dormant?
Yes. Figs require 6 to 10 weeks of temperatures between 30 and 45°F to reset their growth hormones. Without dormancy, spring growth is weak and fruit production declines. An unheated greenhouse provides natural dormancy in most climates.
How many figs does a greenhouse tree produce?
A well-managed fig tree in a 10 to 15 gallon container typically produces 20 to 50 figs per season once mature (3+ years). Some varieties produce two crops per year (breba on old wood, main crop on new wood), potentially doubling output.
Can I grow figs from cuttings?
Yes — figs root easily from dormant hardwood cuttings taken in late winter. Cut 8 to 10 inch sections of pencil-diameter wood, dip in rooting hormone, and stick in moist perlite or potting mix under a humidity dome with bottom heat. Roots develop in 4 to 8 weeks. This is a free way to propagate new trees from established stock.
Fig Pests and Diseases in the Greenhouse
Figs in greenhouses are generally pest-resistant, but the enclosed environment creates conditions favorable for a few common problems. Spider mites thrive in the hot, dry conditions of a summer greenhouse and attack fig leaves, causing stippled yellowing and eventual defoliation. Increase humidity with misting and release predatory mites for biological control. Fig rust — an orange-spotted fungal disease on leaf undersides — can persist year to year in a greenhouse where infected leaves are not removed and disposed of. Sanitize fallen leaves promptly and improve air circulation to prevent recurrence.
Root-knot nematodes are a less common but serious problem for container figs. These microscopic worms invade roots and form galls that restrict water and nutrient uptake. Prevent introduction by using sterile potting mix and clean containers. If nematodes are suspected (stunted growth, yellowing, and galled roots visible when repotting), discard the growing medium, wash and sanitize the roots and container, and repot in fresh sterile mix.
Training and Pruning for Container Figs
Prune figs in late winter while dormant (February or early March in most climates). Remove dead wood, crossing branches, and any growth directed toward the center of the canopy. Head back the previous year's growth by one-third to one-half to control height and encourage branching. Figs fruit on current-season wood, so hard pruning does not sacrifice the current year's crop — it actually promotes more fruiting wood.
Some growers train container figs as open-center vase shapes (3 to 4 main scaffold branches radiating from a short central trunk) for maximum light penetration and air circulation. Others prefer a single-leader form for narrow spaces. Either training system works; the key is consistent annual pruning to keep the tree at a manageable size for its container and greenhouse space.