The Best Soil for Fig Trees in Pots (and in the Ground)
Most of the soil questions I get are about potted fig trees, and for good reason. A fig tree in the ground can find what it needs. A fig tree in a pot is basically living in a box, and the soil is everything it has.
Hey there, fig growers! I'm Ross, the "Fig Boss," and I've dedicated my life to this amazing fruit since 2014. I propagate thousands of fig trees every year, and a lot of them spend their first years in pots. When people see my potted trees, the first thing they ask is what soil I'm using.
So here's the full answer. I'll cover in-ground soil too, but most of this guide is about potted fig trees, because that's where soil makes or breaks the tree: what I put in my containers, the compost mistake I see all the time, why I highly recommend ProMix, and how to cover every nutrient a container fig needs.
Why Soil Matters More for Potted Fig Trees
In the ground, a fig tree with a strong root system transitions well, and most native soil is at least sufficient. In a pot, the tree only has the soil you give it.
When I plant a potted fig tree in the ground, once it has a strong root system, it usually transitions very well. I add compost or mulch on the surface, and that's about it. There's usually no nutrient deficiency, because most people have a native soil that's at least sufficient for a fig.
Potted fig trees are different. They're basically in a box, and if that box doesn't have drainage holes, you can have a huge problem with overwatering. Fig tree roots are very sensitive to sitting in water because the root system is so fibrous.
And it's not just overwatering. People with potted figs struggle with underwatering too. They just can't seem to get it right. The right soil and good drainage make it a lot easier to keep the right level of moisture and have a healthier tree, no matter what container you're growing in.
Consistent Moisture Is Half the Battle
A container's soil dries out a lot faster than the ground, and a lack of soil moisture is the most common reason figs drop. Fig trees are drought tolerant; their fruit isn't. Varieties like Pastiliere and Celeste drop their figs quickly when the soil dries out. More in why figs drop before they ripen.
In summer, a potted fig usually needs water every day, roughly a quarter gallon to a gallon per 5 gallons of soil, depending on the tree, its leaves, and its sun. Stick your hand in the soil before you water. Too much water shows up as yellowing lower leaves, usually from waterlogged soil or root rot, which is very common in pots. Here's my guide to yellowing fig tree leaves.
Some varieties are less forgiving than others. LSU Purple is resistant to root-knot nematodes, but it's unforgiving of dry soil: it holds on to figs that were damaged when the soil dried out. Here's what both look like:
Consistent doesn't mean soggy, though. A slightly drier soil gives you sweeter, more intense figs with a longer shelf life, because excess water gets stored in the fruit and dilutes the sugars. The goal is the same amount of water every day, not a flood once or twice a week.
That's exactly why soil matters so much in a container: a well-draining mix holds enough water for the day without staying waterlogged. My full fig tree watering guide covers how much and when.
For young trees, I use 4 x 9-inch Treepots with drainage holes. They're the same 1-gallon pots I root and grow my own trees in. For bigger trees, here's my fig tree container size guide.
Fig Tree Roots: Fibrous, Wide, and Not a Threat to Your Foundation
A fig tree grown from a cutting has a fibrous root system, mostly in the top foot of soil, with no big taproot.
This is one of the things people always get wrong about fig trees and foundations. Fig trees won't damage your foundation. When they're propagated from a cutting, the root system is usually very fibrous in the first foot of soil. They don't have big taproots, the big roots that destroy things.
Where you do need to be careful is underground pipes. Fibrous roots can still grow around and into them, like most trees.
Those roots also spread wide, usually about two times the width of the tree's canopy, and they're really good at finding water and nutrients. More on planting near your house in my fig tree spacing guide and my list of 20 facts about fig trees.
Why I Grow Thousands of Fig Trees in Pots
Pots are my proving ground. I trial new varieties in containers, and the ones worth keeping get planted in the ground.
Growing fig trees in pots is part of my trialing process. Every year I trial a lot of varieties in containers, and if I like to eat them or they have good traits, they get upgraded to the ground.
There are many more benefits to growing figs in the ground (here's my full comparison of fig trees in pots vs. the ground). But if a pot is what you want, or your only option, fig trees make great container plants. Part of the reason I trial in pots is that they're so darn reliable.
Sunlight, watering, and winter storage for containers are in my potted fig tree care guide.
A First-Season Training Tip for Potted Fig Trees
In the first growing season after rooting, remove the apical bud once the leaves start getting really big. The signal is leaf size, not the height of the tree.
People usually think about height. For me it's the size of the leaves: really big leaves tell me the tree is very healthy and has a lot of access to sunlight, which is the main limiting factor. Without much sun, you won't get much out of removing the bud.
Removing the apical bud changes the auxin and hormones in the tree. The tip can no longer grow, so the tree sends out new branches that compete with each other, racing for the sun. That's scaffold development in the first year. More in the role of plant hormones in fig tree pruning.
You can grow it as a single stem or even three trunks in a pot. Those first-year scaffolds mean more buds going into the next season, so don't prune them away; don't do really any pruning at that point. The tree fruits easier, at a higher quality, and ripens earlier.
The Alternative: Growing One Tall Whip
The alternative is to let the tree grow as a single-stem whip all first season. In a container, it can grow six to eight feet, and then people cut it back to two, three, or four feet while it's dormant.
It's not necessarily a bad option, but in my opinion it wastes a whole growing season. The tree starts year two with no scaffolds, and if it was cut back really far, the scaffolds that develop may not fruit very well that year. Some people like it for long-term form on big potted trees, and either method works for that. With the apical bud method, you can get very high-quality fruit in year two.
More on this in pinching fig trees, training young fig trees, and why I summer prune for form. For established container trees, see my guide to pruning fig trees in containers.
Why a training tip in a soil article? Because none of it works if the tree isn't healthy. Without enough soil, enough air in it, the right moisture, and the right nutrients, you'll struggle no matter what you do. The right soil produces the healthy leaves and growth that lead to fruit.
The Best Soil for Fig Trees in the Ground
The best soil for a fig tree is, of course, well-draining. If yours isn't, fix the drainage before you worry about anything else.
Break through the hardpan. If you dig down about 8 to 12 inches and hit a very hard layer of soil that's basically impenetrable for a tree's roots, break it up when you plant. That helps with drainage. A lot of people do this in different areas of their yard.
Plant on higher ground. Avoid low areas that collect water, flood, or don't drain well.
Do a percolation test. Dig a hole, fill it with water, and time how long it takes to drain. That tells you whether the spot drains well before you plant.
Clay Soil: Change the Texture From the Surface
People add all kinds of things to their soil to help drainage and improve the texture. Clay is thick and dense, with much smaller particles, and a lot of us in the United States have clay-based soil.
Instead of amending the soil and mixing amendments into the planting hole, I change the texture from the surface. If you dig a hole and add a whole bunch of amendments to try to change the texture, your fig tree's roots may not venture out past the hole you dug. You've basically created a container in the ground, and that's not good long term.
So I go to the surface with mulch and compost. You wouldn't believe how much it changes the texture in just a couple of years. It brings in insects, worms, and other beneficial life that breaks down and changes the surface soil. Add a couple of inches of compost a year for a few years, and you can really change the top inch or two of your soil. That makes a dramatic difference for your tree.
Get a Soil Test
Because their roots search so widely, in-ground figs usually don't have nutritional deficiencies. Still, I highly recommend a soil test. It's very cheap, and the analysis tells you what you're deficient in and exactly how much of what to apply, instead of guessing, which is kind of what we do with containers.
Soil pH: Aim for 6 to 7.5
If the pH is off, the tree won't take up specific nutrients as well as it should. Aim for as close to neutral as possible, anywhere between 6 and 7.5. Above 7.5 you'll see some chlorosis (yellowing leaves), and below 6 you might start to see it too. Lime raises pH, and sulfur lowers it, and your soil test tells you which one you need. If you're growing fig trees in pots, you almost never have to worry about pH. Don't stress yourself out.
When you plant or transplant, backfill and tamp the soil firmly to eliminate air pockets. Air pockets can stunt growth and cause defoliation and fruit drop. Everything else is in my fig tree planting masterclass and my guide to transplanting fig trees.
The Best Soil for Potted Fig Trees
With containers, we choose the soil. Your native soil doesn't matter at all.
My Favorite: Fully Broken-Down Mushroom Compost
The best soil I've found for containers is something I can only source locally here in Pennsylvania: mushroom compost. You might see it in a store or as a bagged product. I get mine delivered from Kennett Square, Pennsylvania, the mushroom capital of the world.
The farms there grow their mushrooms on a substrate, then compost that substrate down, and that becomes mushroom compost. They deliver it, or nurseries pick it up, and it gets divvied out from there to people like me. Two different local companies deliver the same stuff to me, and it's extremely cheap: four yards cost me about $200. The same amount of ProMix HP would cost me a fortune. That's originally why I went for it. The texture is a bit dense, especially in the middle of the pile, but it has a ton of life in it, and I use it in my garden too.
I wanted a compost-based soil for my fig trees with lots of life and fungus in it, a whole mycorrhizal network. I have read some scientific studies saying that certain plants, like the brassica family and even fig trees, don't really benefit from certain species and strains of soil microbes that help other plants. In my experience, that's just not true. I've seen a huge difference in the health of my trees from a horticultural standpoint after using this compost.
I also use mycorrhizal fungi products. You can add them to any of your pots, and you can use them to inoculate your garden beds too. Water them in and follow the directions. Compost tea is another way to add life. The microbes in your soil help your plants take up water and nutrients better.
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I like everything with life. Think of our own microbiomes: take the wrong strain of a certain bacteria, and it might not do anything for your gut. Soil life is the same, and there's still a lot of science to be done on soil microbiology.
The Compost Mistake That Steals Nitrogen From Potted Figs
Compost for potted fig trees is a really bad idea if you get the wrong product. The main thing you're looking for is that it's fully broken down.
It's ideal if it's organic, but that's not what I mean. Wood or wood chips are often one of the materials used in composting, and wood chips don't break down very quickly. If the compost isn't fully broken down, you end up with large pieces of hardwood in it, and as those pieces break down, they steal nitrogen from your potted plants, fig trees or not.
You then have to compensate with a whole lot of fertilizer, and most people don't compensate enough. Trust me, I've grown fig trees in compost-based products where the wood wasn't broken down, and they really didn't like it. The sign I see most isn't yellow leaves; it's lots of fig mosaic virus symptoms. More on that below.
My rule: when you buy a compost-based product, there should be no pieces of wood bigger than about a quarter. If there are lots of them, that product isn't made for containers.
Almost all the bagged products you can buy have big woody pieces in them. They're made for the ground, where a little woody material on the surface isn't going to kill your tree. In pots, you really have to be careful.
Even one brand can be inconsistent. Years ago I used Just Natural Soil Conditioner, and half the time it was broken down and half the time it wasn't, depending on the batch and how fast they were trying to move product.
Better Compost Options for Containers
Homemade compost: You control exactly how broken down it is.
Worm castings: They shouldn't have any woody pieces in them. They're more expensive.
Mushroom compost or mushroom compost blends: Usually not many woody pieces, if you can find it.
FoxFarm and Coast of Maine: Two brands I'd recommend. I've also used Coast of Maine's Bumper Crop Soil Builder in the past.
These are all decent options, and the benefit of using them is the added life they bring.
The Simple Answer: ProMix (or Make Your Own)
If you don't want to worry about big pieces of wood stealing your nitrogen, just go with ProMix, or make your own version of it.
Your own version is very cheap and affordable: it's just peat moss and perlite. You can mix them in different ratios:
70% peat moss, 30% perlite or vermiculite: A very high-porosity mix. It's what I use for rooting cuttings.
85% peat moss, 15% perlite: A little higher on the peat.
Bagged: ProMix HP or ProMix BX (this one comes with mycorrhizae), whichever you have access to and can afford.
If you're rooting your own trees, the same mix works for cuttings, and for pre-rooting I use long-fibered sphagnum peat moss. My step-by-step is in growing figs from cuttings, and when and how to fertilize fig cuttings covers feeding them once they're rooted.
The trade-off is that a homemade mix like this is pretty much sterile. The peat is sterilized for nursery production, so there are no weed seeds, very little life, and very few nutrients. But you can always add life to a soil like that: top it off with compost, worm castings, or a mycorrhizae product, or mix them in. Not every ProMix has mycorrhizae built in, but in my experience most of them do, so if you want that extra bit of life in a bagged mix, ProMix is a great product.
That's the short, simple answer I give people when they ask what soil to use for their potted fig trees: it's probably just ProMix. When you move a tree into a bigger pot, set the top of the root ball about an inch below the rim, tease apart circling roots, firm the soil to remove air pockets, water it through, then add your slow-release fertilizer and a layer of mulch. The full steps are in my repotting tips for fig trees.
Fig Mosaic Virus and Soil: A Healthy Tree Shows Fewer Symptoms
Every fig tree has fig mosaic virus (FMV). There's no need to quarantine your tree or get rid of it.
I've done extensive testing, and I get this question a lot: should I quarantine it, or get rid of it? That's very extreme, and there's nothing to worry about.
Some varieties, and some fig trees from certain growers, have the virus at a much higher severity. So if you're buying a fig tree, make sure the seller understands how to lessen the severity of the virus. The main way to do that is rejuvenation pruning, which I've talked about many, many times. Here's my guide to buying a fig tree without the scams and hype.
The other big factor is whether your tree is healthy. Our bodies carry lots of rogue viruses, and our immune systems fight them off. Fig trees are the same, and the main way to a healthy fig tree is to start with the soil and correct any nutritional deficiencies. If you're constantly fighting deficiencies because your compost isn't broken down, you're going to have a really hard time.
Read more in my full guide to fig mosaic virus.
Soil Temperature: The Fertilizer You Didn't Know About
Fig trees aren't really metabolically active until the soil gets above about 50°F. The optimal soil temperature is 78°F.
It's not really a fertilizer, but heat is one most people don't know about. Plant beans, squash, or tomatoes before the soil warms up and they just sit there, because they're not metabolically active. Fig trees are the same.
Around 45°F: They start growing some roots.
50s: They start showing a little more life.
50 to 60°F, 60 to 70°F, and up to 80°F: Each step is a huge difference.
78°F: The best, optimal soil temperature.
You and I have our own metabolism, controlled through homeostasis: we shiver when we're cold and sweat when we're hot. Our bodies don't run efficiently at the wrong temperature, and neither do fig trees. You can dump as much fertilizer on them as you want, but they won't take up water and nutrients if the soil is too cold.
One spring, about a month and a half after we took my potted patio figs out of winter storage, on May 19th, they were amazingly lush, and about 75% already had fruit or the beginnings of fruit. It was an exceptionally warm year, about two weeks ahead of normal, and I hadn't fed them at all yet. No signs of deficiencies, good fruit set. Could fertilizer have given even more? Possibly. But it shows how powerful heat is.
I still recommend feeding potted figs first thing in the season, as soon as they wake up. Just know that warm soil is what lets that fertilizer work. If your tree is stalled in spring, read is my fig tree dead? before you reach for more fertilizer.
Feeding Potted Fig Trees: Cover Every Nutrient
An in-ground fig tree can venture out and find what it needs. A potted fig tree can only use what you've put in the container.
In the ground, that wide, fibrous root system near the surface makes it very easy for a fig to find nutrients and water. In a pot, if you're missing a key nutrient, the tree can't go find it. There's only so much soil and only so many inputs you've actually put into the container.
You have to apply some kind of fertilizer every year to potted figs for them to produce. So it's really important to apply one with a wide spectrum that covers every nutrient the tree might need. It's like vitamins and minerals for us: a deficiency is a big deal, and correcting it makes a huge difference in your health. There's no such thing as a fig-specific fertilizer, either; that's a marketing gimmick.
Macronutrients: NPK (nitrogen, phosphorus, and potassium).
Secondary nutrients: calcium, magnesium, and sulfur.
Trace elements: all of the micronutrients beyond those.
What I Use: One Controlled-Release Application per Season
An easy way to cover everything is a synthetic, controlled-release product like Osmocote. It's what I use in my nursery production. In my case, I use Calibercote, Classicote, or Florikan. These are separate products, and there are many names for this stuff, and in the nursery business you can buy it in bigger 50-pound bags.
The label tells you exactly what the NPK is, which micronutrients it includes, and how long it lasts. The Calibercote I use is an 18-6-12 that lasts about six months, which is the length of my entire growing season. Anything around a 20-10-20 is really good, and you definitely don't need a lot of phosphorus. So I apply it once at the start of the year, and it's done. When you have hundreds or thousands of fig trees to take care of, there's really no better way to feed them, and organic fertilizer would get very expensive at that scale.
Going Deeper: Trace Minerals and Other Additives
Want to get into the minutiae? A controlled-release fertilizer doesn't have every trace mineral. These are all good additions to a fertilizer regimen:
Greensand or rock dust: A broad range of trace minerals.
Silica: A really important one. I use diatomaceous earth.
Calcium and magnesium: Oyster shells, lime, and gypsum.
Sulfur and boron: Boron is a really good one, and something like borax could work.
Do you have to do all of them? No. I did this once and walked away for years. It's been a couple of years since I really got into the weeds of fertilizing my fig trees.
Organic Options
Organic fertilizers can be more powerful and are probably better for the tree. Synthetic fertilizer breaks down into salts, and salt kills bacteria and fungi; it's a preservative. Organic brings life to your soil instead.
Fish fertilizer or fish emulsion, like Alaska Fish Fertilizer.
Manures, like rabbit manure.
Blood meal and bone meal.
