Figs George Ray McEachern
Texas A & M University
College Station, Texas 77843-2134
December 9, 1996
Figs (Ficus carica, L.) have been a part of Texas homesteads since the early development of the state. Figs grow extremely well along the Texas Gulf Coast, but dooryard trees can be grown in any section of Texas. In the northern portions of the state, fig trees will require some cold protection and supplemental irrigation will be needed in arid areas or during extended dry periods.
The fig fruit is unique. Unlike most fruit, in which the edible structure is matured ovary tissue, the fig's edible structure is actually stem tissue. The fig fruit is an inverted flower with both the male and female flower parts enclosed in stem tissue. The structure is known botanically as a synconium. At maturity the interior of the fig contains only the remains of these flower structures, including the small gritty structures commonly called seeds. Actually, these so-called seeds are usually nothing more than unfertilized ovaries that failed to develop, and they impart the resin-like flavor associated with figs.Site Requirements
Figs require full sunlight for maximum fruit production. When choosing a site for figs, select an area that has sun for most of the day, or, expect reduced performance from the trees. Early morning sun is particularly important to dry dew from the plants, thereby reducing the incidence of diseases. Figs are frost and freeze sensitive and perform best south of the 800-hour chilling zone. Mature figs which are fully dormant can endure temperatures of 10 degrees F with little damage.
Although figs can be grown in all types of soil, they do not tolerate poorly drained sites. Avoid sites and soils where water stands for more than 24 hours after a rain. In areas of poor drainage, roots receive insufficient oxygen, which results in stunted growth and eventual death of the tree. Figs are relatively salt-tolerant and can be grown along the coast near brackish water.
There are four distinct types of figs; however, the only one that is significant to commercial growers in Texas is the Common Fig.
- Common Fig
These figs develop parthenocarpically (without pollination) and are by far the most prevalent type of fig grown in Texas. The fruit does not have true seeds and is primarily produced on current season wood. Varieties recommended for Texas are of the Common Fig type.
The Caprifig produces a small non-edible fruit; however, the flowers inside the Caprifig produce pollen. This pollen is essential for fertilizing fruit of the Smyrna and San Pedro types. The pollen is transported from the Caprifig to the pollen-sterile types by a Blastophaga wasp. Commercial growers hang baskets of Blastophaga-infested Caprifigs so that the wasps can effectively fertilize the fruit. Caprifigs were grown successfully at Del Rio before 1901.
The Smyrna fig varieties produce large edible fruit with true seeds. The Blastophaga wasp and Caprifigs are required for pollination and normal fruit development. If this fertilization process does not occur, fruit will not develop properly and will fall from the tree. Smyrna-type figs are commonly sold as dried figs.
- San Pedro
This type of fig bears two crops of fruit in one season--one crop on the previous season's growth and a second crop on current growth. The first crop, called the Breba crop, is parthenocarpic and does not require pollination. Fruit of the second crop is the Smyrna type and requires pollination from the Caprifig. Breba crops are produced early in the spring on last season's wood. However, the second crop of the Smyrna type may fail to set because of lack of pollination from Blastophaga and Caprifig. This second crop fruit drop frequently discourages homeowners.
There are a number of Common Fig varieties recommended for Texas.
- Celeste (Malta)
The Celeste fig is small, brown to purple colored, and adapted to all areas of Texas. Celeste is the most cold-hardy of all Texas fig varieties. The tree is large, vigorous, and very productive. Celeste usually does not have a Breba crop; the main crop ripens in mid-June before the main crop of other Texas fig varieties. Celeste has a tight closed eye which inhibits the entry of the dried fruit beetle. The fruit does not have excessive souring on the tree. Celeste has excellent fresh dessert quality with a rich sweet flavor. It is an excellent processing fig, either frozen or processed as fig preserves. Do not prune mature Celeste trees heavily since this can reduce the crop.
- Texas Everbearing (Brown Turkey)
Texas Everbearing is a medium sized fig adapted to Central and East Texas. It is the most common variety in Central Texas. The tree is vigorous, very large, and productive. The early crop ripens in May; the main crop ripens in late June and continues to ripen into August. The fruit has a short, plump stem and moderately closed eye which reduces souring on the tree. The fruit is nearly seedless and has a mild sweet flavor. Early crop fruit is very large, sometimes 2 inches in diameter.
Alma is a Common Fig variety released by the Texas Agricultural Experiment Station in 1974. Alma resulted from a cross between the female Allison and the male Hamma Caprifig. It is a late season variety with very high fruit quality. The fruit skin is rather unattractive; however, the flesh has an excellent rich, sweet flavor. The tree is moderately vigorous, very productive, and comes into production at a very early age. The eye of Alma fruit is sealed with a drop of thick resin that inhibits the entry of the dried fruit beetle, thus reducing on-the-tree fruit souring. Alma is very frost sensitive, especially as a young tree, and typically survives best when grown within 200 miles from the Gulf of Mexico.
This variety (Madonna, Dalmatia, Brunswick) is the most popular commercial canning fig in the South. It is a weak growing tree with fruit that sours and splits badly during wet weather. Splitting and souring can be reduced, however, if its fruits are picked just before full maturity and used as preserves. This variety also produces fair-to-good crops on sucker wood the season after freeze injury. The fruit is medium to large with brown skin and light amber pulp. It is prominently swollen at the fruit base with a very open eye. Fruiting is spread over a long period if the tree is pruned heavily. Figs will appear on both current and previous seasons growth. This variety is widely used as a dooryard variety in Texas but because of its splitting and souring problems, it is no longer recommended.
This variety (Gentile, White Endich, Dottato) is the commercial fig of California. Varietal trials show it does well in Texas, particularly in South Texas. The fruit becomes rubbery in drier and hotter areas. The eye is open but it is characteristically filled with a honey-like substance which prevents entry of insects and subsequent souring. Fruiting characteristics are similar to those of Magnolia and Everbearing. It will produce on sucker wood the year after cold injury. The fruit is yellow to green with seeds and amber pulp. The fruit is excellent canned or preserved. Do not plant this variety in drier areas of Texas.
Figs should be spaced 12 to 20 feet apart and should not be fertilized at planting. Figs should be cut back when they are transplanted and survive better if set 2 to 4 inches deeper than they were grown in the nursery. The "heading back" develops lateral branches and reduces water loss from the above ground portion. Since the root system may be damaged during transplanting operations, water uptake may be reduced until they become established. Fig trees planted in late fall often develop root systems before leafing out in the spring, but because young trees are more susceptible to cold injury, it is often advisable to delay transplanting until just before dormancy is broken in early spring. Young trees to be transplanted should be dug with care to prevent root damage. Inspect trees bought from nurseries to insure that roots are healthy and are not damaged. Remove any broken or dried roots and transplant young trees into a hole deeper and wider than necessary for the root system. Crumble the soil around the roots, and pack it down several times during the filling operation to bring all roots into contact with moist soil. After planting, water the tree to settle the soil firmly around the roots. If conditions are extremely dry, watering before the hole is completely filled is beneficial.
Figs should be trained into a single trunk, open vase-type tree if planted in the 200-hour chilling zone. The stool multi-trunk system is by far the most frequently used in Texas because freezes occasionally kill the upper part of the plant. The stool system is common where freezes occasionally kill the upper part of the tree. Figure 1 illustrates the two types of training methods.
Figure 1. Mature figs trees trained to a multi-trunk stool type and single trunk, open vase type (click on image to see larger view).Pruning
Figs should be pruned very little. Do not prune mature Celeste and Alma trees because this reduces the crop size. Texas Everbearing produces a fair crop following a heavy winter pruning. To stimulate new growth thin out older trees which grow very little each year. Thinning also increases fruit size. Prune the trees enough to stimulate approximately 1 foot of growth each year. Remove all weak, diseased, or dead limbs each dormant season.
Figs can be propagated by suckers, layering, or cuttings. Suckers from the crown of the bush are not advisable because they will transfer nematodes from the roots of the mother bush. The easiest way to propagate figs is by stem cuttings.
First, collect six-inch to eight-inch terminal shoots of healthy one-year growth in late winter. Next, group the cuttings in bundles for callusing, as illustrated in Figure 2.
Invert the bundles in a callusing trench from mid-January to mid-April, covering the basal ends of the cuttings with approximately two to four inches of soil (Figure 3).
The callusing trench should be well-drained and weed free. After callusing, place the cuttings right side up in a propagation row (Figure 4).
Cuttings should be planted with one inch above the soil line and six inches below the soil line. They should be spaced six to 12 inches apart in the row. In just one year in the propagation row, the cuttings will develop roots and shoots can make 36 to 48 inches of growth. The small tree will be ready for transplanting during the dormant season.
Soil moisture must be managed carefully because most roots of the fig trees are close to the soil surface and can easily dry out. Figs are very susceptible to soilborne nematodes that feed on small roots and reduce water movement into the tree. For these reasons, apply water to the trees as drought develops. Slight leaf wilting in the afternoon is a good indication of water stress. Mulching with straw or grass clippings helps maintain uniform soil moisture and reduces weed competition for available soil water. Water stress frequently causes premature fruit drop of Texas fig varieties which do not have true seeds. This problem is very common in hot, dry areas when the fig tree is grown in shallow soil and roots are nematode infested. Trees planted in shallow sites are subject to injury or death when the soil is saturated with water. Good water management, including regular irrigation and mulching, helps maintain tree health and vigor and reduces fruit drop.
Dormancy and Cold
Factors influencing a fig tree's susceptibility to cold injury are related to the tree's entrance into dormancy. A mature tree which has lost all of its leaves and becomes totally dormant can withstand much cooler temperatures than a rapidly growing tree at the time of first frost. Limiting irrigation in the fall of the year to reduce growth will encourage the onset of dormancy. A fully dormant fig tree can withstand temperatures as low as 10 degrees F. In North Texas, plant figs along the south side of a building to help reduce freeze damage. Straw mulches placed well over the base of the tree will help to insulate the tree during freezes and help prevent killing the crown of the tree (Figure 5). When trees or limbs freeze, give the tree ample time to grow before removing the frozen limbs; then new wood can be produced.
Figs should be allowed to ripen fully on the tree. They must be picked as they ripen; otherwise, spoilage from the dried fruit beetle can occur. On-the-tree spoilage or souring is caused by microorganisms in the fully ripe fruit. These organisms are usually carried into the open eye of the fig by insects, particularly the dried fruit beetle. Daily harvests and the removal of overripe, spoiled figs can greatly reduce spoilage problems. This is particularly true of varieties which have an open eye. Use gloves and long sleeves when harvesting figs to prevent skin irritation from the fig latex.
The major problems for figs in Texas are root-knot nematodes, fig rust, fig souring and cotton root rot.
- The root-knot nematode, Meloidogyne sp., the most important pest that affects Texas figs, is not readily noticed by the average person. They are microscopic soil-inhabiting worms which attack plant's root systems. They attack and feed on roots, causing them to swell or gall, thus interfering with normal uptake of water and nutrients. These galls are easily seen if root samples are observed. Nematode problems may go unnoticed for several years, but as the population builds up, the tree loses vigor and declines gradually. Nematodes infestations can contribute to premature fruit drop. To prevent root-knot nematodes in figs, obtain nematode-free plants and plant in nematode-free soil.
- Fig rust is an important fungal disease that attacks the leaves of figs caused by Physopella fici. Fig rust first appears as small yellowish-orange spots on the leaves. These lesions enlarge slightly and may become very numerous as the season progresses. Rust causes complete defoliation of many trees in the state each year, resulting in ragged-looking trees. In addition, trees defoliated early in the season may initiate new growth, increasing susceptiblity to cold injury. Defoliation does not occur early enough to cause fruit loss except in late ripening varieties. Rust is controlled by neutral copper sprays. One or two applications made in May or early June usually keeps trees in fairly good condition until after fruit ripens. In very wet seasons, one or two additional applications may be necessary. A good index for spraying is when the first leaves on the tree have reached full size. The second spray should follow in 3 to 4 weeks. It is extremely important to get good leaf coverage with the spray material. Fig souring is a constant problem in Texas. The first step in preventing losses attributed to souring is to grow recommended varieties, which have a closed eye, a drooping fruit characteristic, and resistance to fruit splitting. Controlling insects and using resistant varieties restrain most fruit souring problems most of the season. Late season infestations may be impractical to control.
- Cotton Root Rot or Phymatotricham omnivorum is the number one killer of figs in Texas. This organism is a fungus primarily associated with alkaline soils. This organism kills the roots causing the plant to wither and die in a short time. There is no resistant variety or rootstock. The only control, which is impractical at best, is to completely recondition the soil before planting. This means completely altering the soil pH in the area with a soil acidifier. This type of control is not permanent, however. Several other minor diseases associated with figs can be found but are a problem only in more humid areas.
COMMON CAUSES OF FIG FRUIT FAILURE
Condition Probable Cause Suggested Remedies All fruit drops when one-third to two-thirds full size. Wrong variety for area Destroy tree and replant with recommended variety. Leaves drop when mature; fruit withers and fails to mature. Fig rust or other leaf-spot diseases, or a twig blight. Use neutral copper spray. Rake up and burn old leaves. Fruiting is poor; tree growth is retarded. Roots have knots or galls and are distorted. Nematode damage, poor soil conditions or excess water. Mulch and keep moisture level adequate. Fruit fails to mature; leaves are small. Vigorous new wood arises from the base. Low temperatures have killed some stem tissue. Cut tree back to healthy tissue and develop a new top from suckers. Fruit sours and many splits. Unsuitable variety or unusually wet year. If unsuitable variety, replant or pick fruit before maturity and preserve. Fruit is tough and falls prematurely during hot, dry weather. (Celeste only) Excessive heat. No control.
Other pests--birds such as blue jays, mockingbirds, and grackles, cause fruit losses each year. There is no suitable control method; however, early morning harvests prevent losses to some extent. Also, there are a number of synthetic nettings available which may be used to cover trees during the ripening season.