Our brown turkey fig tree was getting some brown leaves and we were wondering how to fix it. So, I did some research to find out more. Here’s what I found.
Fig tree leaves turn brown from improper watering, climate, and nutrients, as well as pests and diseases. For best results, only water fig trees when the soil gets dry. Apply a balanced NPK fertilizer as directed or 2 inches of compost every 1-2 months.
While there are several reasons fig tree leaves turn brown, how can we tell which issue is causing it, and from there—how can we fix it? Let’s take a closer look.
1. Under-Watered
The most common reason fig tree leaves turn brown is a lack of water.
When fig trees are under-watered their leaves become dry, curl, brown, and drop. This issue is made worse when the weather is excessively hot and dry (more on this later).
As many factors determine how much to water your fig trees such as climate, soil, drainage, and elevation, there’s not a set volume of water to use or even a schedule to follow.
However, there is an easy way to check your fig tree’s soil to prevent both under and over-watering.
The best way to water fig trees is by watering only when the top 2-4 inches of soil gets dry. I like to check this by pushing a finger into the soil, under the tree’s canopy.
When watering, soak the ground down to 2 feet deep as over 90% of the fig tree’s roots are found at this depth.
Once you water in this way, the next thing to look at is increasing the soil’s water retention.
Improve Water Retention
After watering, the two best ways to increase your soil’s retention and help your fig trees become water independent are by providing compost and mulch.
Compost provides valuable nutrients and increases the soil’s organic matter. Every 1% increase in organic matter leads to an additional 20,000 gallons of water held per acre of soil.
Mulch dramatically reduces evaporation, regulates soil temperature, and prevents soil erosion. Since fig trees evolved as understory plants in forests, they’re used to plenty of mulch (especially fallen leaves and branches.
Apply 2 inches of compost every 1-2 months and 4-12 inches of mulch every 3-6 months.
As permaculture guru Geoff Lawton says, a forest grows from a fallen forest. And this is true for fruit trees and food forests as well.
2. Extreme Heat
Fig trees are native to Mediterranean climates, so most fruiting varieties (such as brown turkey) do best in warmer and dry weather, typically in zones 6-9.
Because of this, fig trees don’t do too well in temperatures consistently above 90ºF.
When combined with a lack of water, the trees get brown leaves and decline in health. If severe enough, the fig tree dies in a matter of days or hours.
Aim to grow fig trees in USDA hardiness zones 6-9. Avoid temperatures below -10ºF and above 90ºF if possible.
While it’s not always possible to control the weather, you can influence it. Gardeners are finding this out more and more each day and creating microclimates in their backyards and properties.
Creating a Microclimate
Microclimates are a difference in a local climate compared to its greater climate. It can mean using the shade of a single tree, or the shade of a mountainside. Sunlight, wind, moisture, and other factors influence microclimates.
A successful and extreme example is how an oasis can grow in a desert (and no, they’re not mirages!).
Here are some ways you can reduce the effects of heat and help fig trees stay cool.
- Compost and Mulch – providing compost and mulch are two of the best practices anyone can use in their garden. The effects of their moisture retention, nutrient quality, and erosion control are unmatched.
- Partial Shade – while most plants require full sun (6+ hours a day), that doesn’t mean they can tolerate a hot sun. Aim to provide your fig trees with partial shade if temperatures get above 90ºF. Shade from the hot, afternoon (west) sun is most beneficial.
- Plant Density – planting fig trees densely with companion plants not only provides them with benefits such as soil coverage and partial shade, but protection against wind, pests, diseases, and more. It also dramatically retains moisture from transpiration.
Remember, plants (including fig trees) stay cool by sending moisture from their roots to their leaves and through a process called transpiration. Just like humans, plants exhale moisture (transpiration), and this is why walking into a thick canopy feels more humid than an open one.
By covering the soil, creating shade, and capturing transpiration, we’re drastically influencing the microclimate for our plants and giving them the best chance to grow.
To learn more about microclimates, and how you can create them in your backyard, check out this video by Gardener Scott.
3. Improper Nutrients
Excess Nutrients
If you’ve been properly watering, and your climate hasn’t been too hot or dry, the next potential issue is improper nutrients.
Excess nutrients are caused by over-fertilizing. Typically, this is from chemical fertilizers as compost isn’t potent enough. Fast-release fertilizers in particular cause excessive nutrients to be released quickly.
Over-fertilized fig trees often get symptoms such as leaves curling, drooping, browning, and dropping. Sometimes, green leaves can drop from the plant. With too much fertilizer, the fig tree can die.
If you believe you’ve over-fertilized your fig trees, the best way to treat it is by leaching. Leaching is when you water the soil enough that a large amount of nutrients gets pushed further down into deeper soil layers, out of the reach of the fig tree’s roots.
A Lack of Nutrients
| Nutrient Deficiency | Leaf Symptom |
|---|---|
| Nitrogen | Entire leaf is pale or yellow |
| Iron | Dark green veins, rest of the leaf is yellowing |
| Zinc | Yellow blotches |
| Manganese | Broadly pale leaves, foliage color looks mottled or smeared |
Fig trees that lack nutrients most often get yellowing, browning, and dropping leaves. Fortunately, different types of yellow leaves can help narrow down the specific deficiency (see the table above).
However, it’s not always possible to determine which nutrients your soil is lacking (unless you have it tested), so the best way to treat your soil is to provide it with a fertilizer with a complete nutrient profile.
The Best Fertilizer for Fig Trees
The two main ways to fertilize fig trees are chemical fertilizers and compost. Generally, while chemical fertilizers have nutrients in quantity, they often lack quality and can lead to long-term damage to the soil.
This is why gardeners are finding that compost is replacing their fertilizers.
However, chemical fertilizers have their place, especially if we use them as a short-term solution and not the endgame. This way the fig tree gets the boost in nutrients, while not becoming over-reliant on it and ignoring the beneficial soil life.
For fertilizers, aim for a balanced NPK (nitrogen, phosphorus, and potassium, the three main nutrients of plants) and apply as directed on the package. For example, a fertilizer with an NPK of 10-10-10 works nicely.
For compost, apply 2 inches every 1-2 months. Mulch also assists with nutrients (among other benefits), so applying 4-12 inches every 3-6 months pairs perfectly with compost.
Either route you go, you can see which fertilizers and compost I recommend on my recommended fertilizer page.
Soil pH
While nutrients are essential, an imbalanced soil pH means plants can’t absorb nutrients properly.
As with most plants, fig trees prefer a slightly acidic soil pH (6.0-7.5).
This is because a slight acidity dissolves the nutrient solids in the soil and makes them accessible to the plant’s finer roots.
Fourteen of the seventeen essential plant nutrients are obtained from the soil. Before a nutrient can be used by plants it must be dissolved in the soil solution. Most minerals and nutrients are more soluble or available in acid soils than in neutral or slightly alkaline soils.
Donald Bickelhaupt, SUNY College of Environmental Science and Forestry
The best ways to check your soil’s pH are with pH strips or a meter. I prefer using a pH meter since they’re easy to use and affordable. To see which pH meter I use and recommend, check out my recommended tools page.
If you find your fig tree’s soil pH is too acidic (below 6.0), apply alkaline amendments such as wood ash, biochar, or lime.
For soil that’s too alkaline (above 7.5), apply acidic amendments such as sand, peat moss, and coffee grounds.
4. Pests and Diseases
While it’s not as common for fig trees to get brown leaves from pests and diseases, Fig Rust, blight, and nematodes have been known to cause issues. Typically, you can identify pests and diseases from spotted yellow or brown leaves or damage to the tree.
Here are some of the most common diseases and pests fig trees get:
- Fig Rust – A fungus that infects fig trees in the spring, causing the tree’s leaves to yellow and brown, and shed early in the summer and early fall. Can be identified by rust-colored spots underneath the leaves. Treatments include pruning and sprays such as neem oil.
- Blight – Another spring fungus that causes fig tree leaves to have yellow, pink, or white spots or even holes. If untreated, leaves turn brown and fall from the tree. Highly infectious. Treatments include pruning, picking up diseased and dropped leaves, and sprays.
- Nematodes – One of the most common pests that figs can get, nematodes damage the fig tree’s roots and can kill the tree given enough time. Treatments include soil sterilization, sprays, and planting companion plants—such as marigolds.
Other pests and diseases that cause yellow and brown leaves on fig trees include scale, mites, and aphids.
If you’d like more information on these pests and diseases, and how to revive a declining fig tree, consider visiting my other post: How To Save a Dying Fig Tree: 3 Quick Steps.
Final Thoughts
It turns out our brown turkey fig tree was suffering from an excessively hot summer and not enough water. After feeling the soil, it was bone dry.
We checked the soil every 1-3 days and watered it when it was dry. We also provided compost and mulch.
In just a week, the tree recovered and started new leaf growth.
