There are many articles about fertilizing fig trees around the web, but most fail to answer some of the most crucial questions for successful fig production each year.
Therefore, not to repeat what everyone else has written I decided to focus on questions they didn’t answer. Specifically; when to stop fertilizing, why to stop fertilizing, and how different nutrients affect fig trees?
How To Fertilize Fig Trees?
To explain the best possible fertilization of fig trees, I would have to divide it into separate sections about in-ground, potted, young, and old trees. That requires another article which I will most certainly write someday.
However, I have to explain the basics of what fig fertilization should look like in order to discuss when and why to stop.
I like to divide each fig tree growing season into three phases of fertilization. Each being one-third of when the tree starts growing to 1st of August. We will see why the 1st of August is important for fig trees and how we can continue to fertilize even later.
The first phase is fig tree growth when it needs lots of nitrogen. Nitrogen promotes the growth of branches and leaves. I prefer using all-purpose fertilizer, like Miracle-Gro Water Soluble All Purpose Plant Food, with slightly higher N than P and K in this phase.
Why not go for something with even more N? Fig trees are vigorous growers by default. Adding too much nitrogen can make them too bushy, hurting fig development.
In the second phase, figs start to form. It usually happens from the middle to the end of 2nd third of the growing season. Figs are inverted flowers, so in the beginning, they require phosphorus, as all flowers do. At that time, I switch to a flower fertilizer, like Miracle-Gro Water Soluble Bloom Booster Flower Food, with more P than N and K.
High amounts of phosphorus will only help figs to start forming. It doesn’t help them fully develop.
The third phase is all about figs developing into delicious fruit. Like most other fruit, figs require potassium to grow and ripen fully. Standard tomato fertilizers work great, but you want to choose the one that has the lowest amount of N and the biggest amount of K.
I was amazed by the results when I used Tomato Fertilizer 4-18-38 Powder 100% Water Soluble Plus Micro Nutrients and Trace Minerals by Greenway Biotech.
When and Why To Stop Fertilizing Fig Trees?
Most people tend to follow some basic guidelines about when to stop fertilizing fig trees. Usually 1st of August or 1st of July. And that’s completely fine for an average grower.
However, if you want to have the best possible fig fruit consistently each year, you got to do better than that. Especially if the climate isn’t as great as fig trees would like.
To achieve the best results, we must understand when each nutrient is necessary and when it might be counterproductive. I’ve already explained above what each of the three most important plant nutrients does, so now let’s see when they become counterproductive, and it’s time to stop fertilizing with them.
When To Stop Giving Nitrogen to Fig Trees?
Some trees, including figs, want to grow more than they want to produce fruit. Nitrogen is especially bad in situations like these because it can cause too late fig formation. It’s usually the reason why sometimes pinching doesn’t work. It gets counteracted by nitrogen.
You want to stop fertilizing with nitrogen right before it’s time for figs to develop. If you identify fruit buds, they are a good sign to stop giving fig tree nitrogen.
I choose to reduce nitrogen to the minimum instead of removing it completely. I find it to be a perfect balance where the fig tree stays as healthy as possible but isn’t encouraged to keep growing, and instead, it grows fruit.
If you continue to give lots of N to fig trees to the end of the growing season, it can hurt them during the dormancy. If the weather gets warm and sunny for a few days while a fig tree is getting nitrogen, it can prematurely wake up from dormancy and start growing. Then a fig tree will get hurt by cold, and it can die.
When To Stop Giving Phosphorus to Fig Trees?
To encourage a fig tree to grow even more fruit, we give it phosphorus, because as we said, figs are actually inverted flowers. Phosphorus encourages flowering.
Phosphorus stops being useful to fig fruit as soon as it forms, and it’s time to gain volume. However, I wouldn’t advise stopping phosphorus at all. Maybe not even reducing it.
While the fig fruit won’t benefit from P anymore, roots will. Phosphorus is known to build strong and healthy roots. Anyone who studied agronomy or similar majors will know that it’s always said how P is for roots, N for everything above.
That might not be as important in warmer climates, but strong roots can be the difference between dead and alive fig trees come spring in cold climates. Strong and healthy roots survive cold with ease, same as old fig trees can withstand cold much better than young ones.
Once the growing season is nearing its end, you shouldn’t give fig trees phosphorus anymore. Freshly grown roots are still easily affected by the cold.
When To Stop Giving Potassium to Fig Trees?
Potassium (K) is useful for fruit growing and ripening. Other than that, it doesn’t have major benefits to most fruit trees.
I like to stop fertilizing with potassium when figs are 20-30 days in their ripening period at the latest. In other words, I would give my fig trees potassium-rich fertilizer only once when figs form, and that’s it. Providing it to the end of the ripening process can actually reverse the quality of figs.
Potassium helps fruit absorb water and survive drought, but figs are better if they don’t absorb too much water. After all, they are the best in warm, dry areas.
In my experience, figs would become too watery and soft before they were naturally ripe, and I would be forced to pick them early. I would end up with figs that look and feel ripe, but they aren’t.
Conclusion
The way the potassium and nitrogen affect fig trees late in the growing season is why most growers choose to stop fertilizing on the 1st of August at the latest.
Luckily, these severe situations where figs end dormancy at the wrong time because of nitrogen are rare. Otherwise, they would often happen from natural nitrogen sources.
However, potassium affecting fig quality happens more often, and it’s something to consider when it comes to fig fruit. Potassium causing figs to absorb more water can even be linked to figs splitting in humid weather.
Exact dates are not a good measure of when to stop fertilizing fig trees, because different fig varieties don’t form fruit and ripen at the same time.
I hope I’ve explained how it works and when to stop fertilizing with each nutrient so that you can decide on the exact time for your fig variety.