Fruit Trees for Rocky Soil

Q. Which fruit trees are best planted in rocky soil?

The smaller amount of rich compost or soil is present, the more fertilizer fruit trees need. I fertilize fruit trees depending on the previous years growth. If the fruit tree grew abundantly during the previous year, I may skip a year of adding any fertilizer. If it grew adequately, then I know that's how much fertilizer is needed. If it didnt grow very well, then I will put on a full compliment of fertilizer. Rocky soils dont have much soil so, once I found how much to give it I use that amount of fertilizer each year in the spring.

A. As long as trees get the right amount of water and the right kind of fertilizers you can grow fruit trees in marbles!!! The more soil is present, the less often fruit trees are watered and fertilized. The more rocks means fertilizer needs to be applied more often. Granular, quick release fertilizers (many inexpensive fertilizers) should be applied about every 8 to 10 weeks. Slow release fertilizers are applied about every three months.

Fruit trees that are tender to winter cold (they will freeze) should be finished with their fertilizer applications in time for cold weather. So if cold weather usually comes no later than mid December (the Las Vegas area is an example of this) then fertilizer applications should be finished by about August 1. 

        Rocky soil, to me, means soils low in organic content as well as full of rocks. In the desert, these soils may be growing fruit trees that are productive but can handle soils covered in rock on the surface of the soil better than some other fruit trees. I am guessing this definition could be extended into a prepared soil covered with a two to three inch layer of rock.

            Stone fruit trees are like apricots, plums, and peaches; those trees that produce fruit that have a hard “pit” in the center. Stone fruit trees are among the best trees, in general, to grow in rocky soil because of their root’s tolerances to low soil organics, root structure and ability to suck up water from the soil at low levels of soil moisture.

Fig trees can get large, over 40 feet tall, but they also can handle severe pruning to keep them smaller. We have done that over and over at the University orchard in North Las Vegas and have had no issues with it for 15 years! Remember to give them extra water, above and beyond what they need for their growth, if you want them to hang on to their fruit and be productive. Unlike their water needs for growth, they need more water to produce fruit during the hot summers.

Olive trees a make it onto my list of recommended fruit trees to grow in rocky and low organic soils even though it is not used that much by some. Olives can be grown (outside Clark County) for fruit production. The fruit is either used as a condiment (green or black fruit) or the fruit is extracted for its oil (olive oil) or both.

Citrus is probably the most often asked about fruit tree regarding soil organics. Yes, there are huge differences among citrus and their organic requirements. Most citrus are tropical to semitropical which include the true lemons, oranges, clementines and grapefruit. All four of these types of citrus do okay in rocky soils or grown under rocky surface mulch.