Fig Trees Growing in Mojave Desert vs So California are Managed Differently

Q. My Grandfather had fig trees in Southern California. They were the most incredible figs.  He would cut it back to a stump every winter. Every year it would have tons of fruit.  He would pick a lot of it early in order for the other fruit to get big and ripen. He claimed that planting fig trees close to a house caused the roots to grow under the house and cool the roots. His trees were huge.  In the desert of Moapa Valley, we have several fig trees that are old, but they are small, dry, the leaves are burned and they have been stumped, but only every 2 or three years, not every year like my Grandfather did. The trees are fed water with a slow drip system and there is mulch on the ground around the trees.  But the fruits are small and terrible! Many fruits just dry up and drop. They have no shade and are hit with direct heat. Suggestions?

Fig tree being grown without enough water will look like it doesn't have enough, sparse canopy, little new growth and small scorched leaves and will not produce fruit.

A.  Everything I have seen so far regarding figs and the production of fruit in the desert is focused on water. I have grown over 15 varieties of figs over a period of 25 years in the Mohave Desert and all of them have been productive. Problems with the figs are few. 

Dried Fruit Beetle

Dried fruit beetle

The first problem I encountered was the dried fruit beetle. This insect would climb inside the fruit of the figs and cause them to sour. The insect carried with it a bacterial infection of the fruit that caused this problem. If you look at the base of the fig fruit, there is an opening. This opening can be shut or open depending on the variety of fig. Those fig varieties with it open had a bigger problem with the dried fruit beetle than those with fruit openings that are shut. The simple solution is to make sure that fallen fruit and fruit still hanging on the tree after it was mature was collected and put into sealed containers. Dried fruit beetles reproduce in rotting, over mature fruit and spread into soft fruit.

Metallic Green June Beetle

The next problem I had is with the green metallic June beetle. They love fig fruits in particular the white or yellow types like Kadota. They attack and feed on this fruit but the presence is gone in a short time during the summer. I ignore them.

Green June Metallic Beetle

Fig Mosaic Virus

The last problem I have encountered is fig mosaic virus. Not a huge problem but it gets into all of the fig trees eventually. Probably spread by insects from tree to tree. Doesn't hurt the tree and it doesn't hurt the fruit much so I ignore it.

Fig Mosaic Virus

Lack of Water

The really big problem with figs growing in the Mojave Desert is lack of water. Fig trees are big users of water. The tree can grow and look fine with a moderate amount of water. But if there is not enough water the fruits will either drop from the tree early or they will be small and hard, not edible. 

If fig trees get enough water for new growth it is still possible they will not produce a decent crop of figs.

I have had many reports of people growing fig trees with small, hard fruit that are just simply lousy. Until I see something different, I believe this is a lack of water. You can apply small amounts of water daily and still not give the tree enough water for good fruit production. It is not a question of how often the tree is watered but more it is a question of how much water the tree is given in a single application. In the middle of summe middle trees up to 10 or 12 feet tall may require 90 - 100 gallons of water each week. I have found the best way to irrigate fig trees is by filling a basin beneath the tree that is 4 to 6 inches deep, 2 to 3 times each week during the summer. This can be done with the hose or with an irrigation bubbler. If drip emitters are used, there must be enough emitters and they must be on long enough to deliver this amount of water. This could be hours depending upon the number of emitters and their size.