Planting a fig tree is not that difficult, in my opinion, mainly because figs can grow in a wide range of soil types. From fertilizing to soil pH levels, figs can thrive in most average conditions. I tend not to get carried away with getting the perfect pH level because soil rarely goes out of average pH for figs, but instead, I focus on other essential things. That said, checking PH levels and being in the best range for growing figs can also be important.
Do figs like acidic soil?
North American fig tree species grow best in slightly acidic soil with pH levels between 5.5 and 6.5. Fig trees tolerate pH levels up to 8.0; however, their growth and fruit quality won’t be the best. Mediterranean fig species are best grown at a neutral pH level of around 7.0.
Why Are pH Levels Not the Same for All Fig Tree Species?
I’ve stated above that optimal pH levels are not the same for all fig species. Since there is not that much information about pH levels for different fig species on the internet, I will make a short explanation. This information is based on my own experience backed by a lot of research into the origin of fig species.
Figs originated from Southwest Asia, where Europe, Asia, and Africa meet between the Arabian peninsula and the Mediterranean. Historically, that area is known as drylands, with soils typically found in areas surrounding deserts and coastal deserts. Cultures that grow in those areas developed with the constant presence of seawater, which is alkaline with pH levels of 7.5 – 8.5. Winds, typically present in the Mediterranean and Southwest Asia, carry seawater particles hundreds of miles inland. There is a lack of rain, which raises pH levels even more.
As a result, fig species that stood the same as they developed in the Mediterranean thrive in neutral pH soil. I couldn’t find historical evidence, but judging by the pH levels of soil where figs originated, it could be that figs thrived in slightly alkaline soil several centuries ago. On the other hand, fig species crossed and developed in other parts of the world, like North America, adapted to slightly more acidic soil due to the lower presence of alkaline factors.
Since there are 873 species of fig trees, keep in mind that some rare species might not follow this logic of origin.
How To Test Soil PH?
I perform two pH tests depending on how accurate pH I believe is required for a certain fig species. One is relatively accurate, and the other only tells you if the soil is acidic, alkaline, or neutral. Countless procedure articles dwell into too many details, so I will explain it straightforwardly because the margin of error with these methods is meager.
Testing Soil pH With Vinegar and Baking Soda
If your goal is to get neutral pH soil, this is the only method you need.
- Take two soil samples – Dig two soil samples, preferably from 2 feet deep if planting in-ground. Take enough to fill a small bowl and divide into two.
- Mix both soil samples with distilled water – Separately mix soil samples with distilled water just enough to turn it into mud.
- Add vinegar to one sample – Pour half a cup of vinegar to one of the samples and watch closely for foam, constantly appearing bubbles, or fizzing sound. If any of it is present, it means your soil is alkaline.
- Add baking soda to other sample – Add half a cup of baking soda to the other sample and again, watch for foam, bubbles, and fizzing sound. If any of it happens, your soil is acidic.
If nothing happens in both cases, then your soil is neutral or near neutral. I like to do both just in case, even though one is enough to determine the results if there is a reaction. For the first time, it’s better to do both just to notice the difference a bit better.
Testing Soil pH With Soil Strips
This method is way more accurate because you can determine how acidic or alkaline your soil is.
- Take a soil sample – Dig out a soil sample, preferably from 2 feet deep if planting in-ground. Take enough to half-fill a bowl.
- Mix the sample with distilled water – Mix the sample with closely equal volume of distilled water. Always use distilled water because it’s pH neutral.
- Stir the soil up – stir the soil for a bit to make sure it properly mixes with distiller water and leave it to rest for 20 minutes.
- Pour the water out – pour the water out without too many solid objects. You want to test the water only because roots don’t absorb solid objects, only what is disolved in the water.
- Use pH test strips – Use one strip from Garden Tutor Soil pH Test Strips Kit(or any similar pH strips kit) in the water, following procedure on the box. By how colors on the strip change you can determine the exact pH level of your soil.
- Multiple samples test – For figs and other bigger trees I prefer testing several soil samples around the location where I intend to plant the tree. That way I can get the average and balance it out more accurately.
How To Prepare Your Soil’s pH Levels for Fig Tree Planting?
Remember, the goal is to reach a pH level within that optimal range from 5.5 to 7.0, depending on your species origin. If you have done your pH tests correctly, you know if you need to raise or lower the pH levels of your soil.
In certain areas, you can know if you need to raise or lower pH levels by the type of soil that is naturally present. That is, if you didn’t already add new soil or any fertilizers. Soils in some areas are dominantly acidic or alkaline, depending on the amount of limestone in the area. You can google maps that show pH levels of ground and soil in your area.
How To Lower pH Levels in Soil?
To lower pH levels of soil, you want to add something with low pH to it. However, thinking about several factors, including fertilization and toxicity, will give you an optimal solution.
A common practice is adding aluminum sulfate or sulfur. These are highly effective but, from my experience, highly toxic when used regularly. I’ve experienced a bit with ammonium nitrate as well, and it has a much weaker effect. It’s much safer when used regularly, and anyone can produce it naturally from animal feces.
Using Aluminum Sulfate to Lower pH Levels in Soil
The negative side of aluminum sulfate is that aluminum is toxic for roots when too much of it dissolves in soil. I’ve had a situation where roots didn’t develop properly, and it staggered the growth of my fig tree. I’ve contacted a renowned local agronomist, and she told me what the problem was, and to avoid this in the future, I have to alternate between different types of pH lowering agents.
Using Sulfur to Raise pH Levels in Soil
Sulfur by itself is somewhat weaker in acidity, mainly because it requires time to produce sulfuric acid in contact with soil. Several factors like bacteria, heat, moisture, and sulfur quality dictate how quickly the acid conversion will happen.
In my experience, sulfur on its own is quite unreliable unless you are not limited with time. However, it’s not toxic except when put in direct contact with roots in large quantities.
Same as aluminum sulfate, you can buy sulfur on Amazon.
Using Ammonium Nitrate to Lower pH Levels in Soil
Ammonium nitrate is naturally found in urea in urine and feces, slowly dried outdoors. Both can be used as soil fertilizers and to slightly lower pH levels in the soil. However, the process is a bit up and down, literally. When put in contact with soil, the pH levels spike upward because of ammonia’s alkaline reaction, followed by an acidic reaction from nitrogen. The acidic reaction is stronger, so the overall effect is slightly acidic.
I am mentioning this as a source because it’s absolutely free for those with any farm animals.
Are Coffee Grounds Good for Fig Trees?
Adding coffee grounds to the soil is an excellent way of lowering the pH levels of soil because they are slightly acidic. If they are generally good for fig trees, it depends upon whether you need to lower pH levels. In addition, coffee grounds are a decent source of magnesium, copper phosphorus, and nitrogen, beneficial fertilizers for fig trees.
How To Raise pH Levels in Soil?
Lowering pH levels in the soil is way easier and less dangerous for trees and plants. It’s naturally done by adding limestone to the soil. In areas with lots of limestone, the soil is generally alkaline with high pH levels.
Dolomite limestone is the best option since it has a natural deposit of magnesium carbonate as an addition. It has 10% more alkalinity while enriching the soil with magnesium which is beneficial for every single tree. I’m not in an area that would require me to raise pH levels in soil, but if I ever had to, I would use Dolomite lime.
Amounts to use can be quite different depending on where you are and what type of soil you are dealing with. Luckily, the one I’m recommending has instructions about the amount to use.