Fig trees are popular choices for home orchards because they put very few demands on their growers. They are often marketed as one of the easiest fruit trees to grow and maintain, so it can be extremely frustrating when such an “easy” tree doesn’t seem to grow well.
If your fig tree is not growing it is likely due to disease, pests, or poor cultural practices. These are the primary causes of a fig tree’s stunted growth.
Let’s look at each of these, how they contribute to a fig tree not thriving, and what we can do to mitigate the problem and stimulate growth.
Diseases That Effect Fig Tree Growth
The following diseases may be hindering your fig tree’s growth:
- Botrytis limb blight
- Cold injury
- Crown gall
- Cotton root rot
Botrytis Limb Blight
Botrytis limb blight is a fungal disease that can emerge during wet, cool springtime weather.
- Cankers that appear above and below the fruit
- Die-back on shoots
- Beige colored spores appearing on shoots during the late winter or early spring
The only way to manage botrytis limb blight is to prune infected shoots right below the canker (source).
Fig trees are sensitive to late frosts and hard freezes in the early spring. If the tree has already started showing new growth before a frost or freeze, you may notice that the new growth has been killed by the sudden dip in temperature.
While cold temperatures and die-back are not actual diseases, the dead twigs and tissue on the tree can become breeding grounds for fungi and bacteria that can further harm your tree. Check your tree for signs of cold injury after any late frosts or unexpected springtime freezes.
Prune all dead limbs, twigs, and foliage (source). Mulching around the base of your tree can also help the soil retain some warmth, especially as winter approaches.
Crown gall is a very common disease affecting a wide range of fruit trees. If a tree has an open wound on its roots, trunk, or branches, it is susceptible to the bacterial infection that leads to crown gall.
- Rough, woody tumors (galls) that disrupt the flow of water and nutrients
- Stunted growth
- Increased signs of water stress
The good news is that if your tree is already mature when it contracts crown gall, it may be able to adapt without very many adverse effects.
The bad news is that young trees that contract crown gall are susceptible to secondary problems and are unlikely to ever be robust.
Furthermore, crown gall is very easy to spread through soil, unsanitized pruning tools, or by colonizing roots of other plants that get too close. Sanitize all pruning tools with a 10% bleach solution if you suspect crown gall. It may also be best to uproot infected trees and burn them to prevent further spread (source).
Cotton Root Rot
Cotton root rot is caused by fungi that can only exist in slightly alkaline, calcareous clay loam soils and in regions that have hot summers. In the United States, cotton root rot only affects plants–including but not limited to fig trees–in the Southwest.
There are three primary fungi that cause cotton root rot, and all are soil-borne. By the time growers see any above-ground symptoms, they have already taken over the tree’s entire root system. Affected trees can often be uprooted with almost no effort.
- Leaves turn yellow or bronze during the summer, followed by permanent wilting three days later
- Sudden death, even following periods of robust growth
The fungi that cause cotton root rot can survive in the soil for years, even deep beneath the surface. Unfortunately, most of the treatments that exist, like planting wheat or other cereal crops on an infected site, are only helpful to commercial growers.
If you suspect your fig tree may have had cotton root rot, don’t plant another one on the same site (source).
While there are a variety of insects that enjoy feeding on fig tree fruits, they are unlikely to cause the kind of problems that lead to stunted growth. One pest, however, can cause significant problems for fig growers.
Root-knot nematodes are one of the more common diseases among fig trees. Nematodes are parasites that live in the soil and penetrate a tree’s roots, making themselves right at home. The roots consequently form knots or “galls” and eventually rot and die.
- Stunted growth
- Pale green leaves
- Failure to produce fruit or reduced yields
Prevention is the only treatment. Nematodes multiply very quickly, and there are no chemical nematicides that are safe for use in a home garden. When choosing a planting site, take a soil sample to your local Extension agent or horticulturalist and ask for a nematode test if you don’t know the planting history of that site (source).
If none of the above seem like probable reasons for your fig tree’s stunted growth, there may be a problem with how your tree has been cultivated. It is fairly common for gardeners to accidentally contribute to the poor health of their fruit trees.
Certain fig tree cultivars can only be cross-pollinated by a specific wasp species. Unfortunately for the rest of the United States, this wasp doesn’t survive in very many places outside of California. If your tree is failing to bear fruit, this could be why.
There are many varieties that don’t require cross-pollination from insects or another tree. Consult your local Extension agent or garden center to learn which fig varieties are right for your region and growing conditions (source).
Fig trees don’t require much pruning, except to remove dead limbs or to improve air circulation among the foliage. However, if you prune your tree incorrectly, you may inadvertently cause more problems than you solve.
When you prune your fig tree, make sure to wait until after the fruit ripens. If you prune heavily in the winter, your tree may not set fruit at all the following year.
It’s also important not to prune in a haphazard way. All cuts should be made at a bud or branch. Bare stubs at unproductive points are open invitations to decay organisms (source).
It’s natural to think that increasing the amount of fertilizer you give your tree will encourage growth. However, if you over-fertilize your figs, you will reduce your yields and could stunt your tree.
If your tree’s fruit isn’t developing or ripening properly, it may be a sign that you should fertilize less (source).
Like many other fruit trees, figs require full sun (eight hours per day during the growing season) and well-drained soils. They tolerate a variety of soils, but prefer sandy-clay loam that has a pH level between 6 and 8 (source).
The planting location must be free of soil-borne root-knot nematodes and the fungi that cause cotton root rot, so have your soil tested before you plant.
In cooler areas, plant fig trees on the south sides of buildings to reduce the risk of cold injury.
The best time to plant fig trees is when they are dormant. In warmer zones, you can plant bare-rooted fig trees sometime in the fall or early winter. In colder climates, plant them in early spring when hard freezes are no longer a threat.
Fig trees don’t require fertilization if your soil contains enough nitrogen without it. If your soil test shows low nitrogen, or if several other trees or plants are competing with your fig for nutrients, apply an 8-8-8 or 10-10-10 fertilizer several times throughout the growing season (source).
If you live in an area that receives at least one inch of rainfall per week during the growing season, you will not need to give your fig trees additional water. If your region is drier than that, plan on watering to make up the deficit.
Yellow leaves, dropping leaves, and grass wilting beneath your fig tree are all signs of water stress. If you notice these signs, water your tree thoroughly one or more times per week throughout the summer.
While fig trees are much less exacting than other popular fruit trees, they are not free from difficulties. Diseases, root-knot nematodes, and improper cultural practices can all cause problems that are hard for gardeners to overcome. In many cases, prevention is the best cure, so before you plant, test your soil, choose the right planting location, and find the variety that’s right for you.