It’s baffling out there. Advice about growing avocado trees in containers comes from every direction and often conflicts. Should you use a potting mix that includes organic materials? Which kind of pot should you use? What’s the best variety for growing in a container? Can you actually get fruit from an avocado tree in a container, anyway?
No one can agree.
Here I come to add to the chaos. But my objective is to give clear and reliable information, as I will only talk about my firsthand experience and what I’ve personally seen other successful growers of avocado trees in containers doing. With that, I hope that I can help you have similar success.
The most contentious issue is what kind of mix is best. More to the point, some believe that plant materials such as wood chips or compost should be a part of the mix while others don’t.
The issue is solved through simple observation. If you travel around and look at avocado trees in containers at nurseries and in yards, you discover that various mixes grow healthy avocado trees, including mixes that contain wood chips or compost.
Allow me to show you a few examples of trees I have visited over the years and tell you what mixes they are growing in. You might like to emulate one.
1. The grower of the two trees below is located in San Diego, and he uses mostly his native dirt along with Kellogg’s GroMulch, plus a little coffee grounds and horse manure. You can read the ingredients of the Kellogg’s GroMulch in the link, and note that it is mostly wood chips/compost (“recycled forest products and aged arbor fines”).
2. The grower of the seedlings below has started dozens and dozens of his own trees for grafting and planting into his grove. He uses E.B. Stone’s Cactus and Succulent mix, which is made of (in order of volume from most to least) pumice, aged fir, aged redwood, lava rock, and sand.
Commercial nurseries in California grow hundreds of thousands of avocado trees in containers each year and they have fine tuned their potting mixes into the recipes that they think grow the best trees while keeping costs as low as possible, among a few other concerns. Their potting mix recipes are their trade secrets so they are not always keen to share exactly what is in their mix, but I do know the major ingredients of the mixes used by a couple of good nurseries and I don’t think they would mind my sharing those.
3. Brokaw Nursery in Ventura includes in their potting mix: wood chips, sand, soil, and coco coir.
4. Maddock Ranch Nursery in Fallbrook includes in their mix: soil and redwood chips.
5. Researchers at the University of California have grown thousands of avocados in containers over many decades and they have published the ingredients used in their mixes. In “Propagating Avocados” it is written, “At UC Riverside, we use UC #2 soil mix . . . based on ½ sand, ¼ peat moss, and ¼ nitrogenated redwood compost, plus added nutrients.”
6. While I don’t grow any avocado trees in containers long term, I often start my own trees from seed in containers in order to graft and later plant in my yard or give to friends. I usually use my homemade compost for these trees, which contains a bit of dirt and chicken manure, but is mostly composted wood chips and garden scraps.
7. A few times I have grown avocado trees in Recipe 420 mix with good results also. Recipe 420’s main four ingredients are (in order of volume from most to least) aged fir bark, coir, peat moss, and pumice.
All of the above mixes grow excellent containerized avocado trees, in my observations. Make your own mix using them as a reference or buy one of the bagged mixes (E.B. Stone’s Cactus and Succulent or Recipe 420), and you will be off to a good start.
Similar to the variation in mixes used, I’ve seen that successful growers fertilize their container avocados in different ways. One nursery grower told me she fertilizes her container avocados with urea. Another uses True 4-4-2. A few friends use Osmocote on their avocado trees in containers and get good growth.
Here are some Hass trees growing in containers at Westfalia in South Africa, grown by Omar Diaz, in a mixture of sand and peat moss, and fertilized with Osmocote. Tell me what Omar is doing is not working!
Types of containers
The containers used for Omar’s trees above are harvest bins made of plastic. Is plastic the best material for containers for avocados? And they are square. Is square the best shape?
When Bob Bergh was breeding avocados for the University of California, he grew trees in 30-gallon metal trash cans. “It has been found that trees in the largest cans will mature a maximum of only about 30 fruits under our conditions,” wrote Bergh in 1957.
Plastic, metal, square or round, I don’t think the container material or shape matters much, based on the fact that I’ve seen healthy and productive trees in so many different combinations.
But there is one characteristic that all of these containers share, and that is drainage, in other words, holes — especially holes near the container’s bottom. There must be numerous holes at the bottom of the container because avocado roots cannot stand low oxygen: they need to breath.
Note the happy white avocado roots inside this sleeve that has abundant holes in the bottom half. (Tree is from Subtropica Nursery in Fallbrook.)
Note that this tree below in a sleeve from Brokaw Nursery doesn’t even have a bottom! Now that is drainage.
It can further help drainage to place the containerized avocado tree up on bricks or a pallet, especially if the surface below the container will not sufficiently drain water away — for example, if the container is on concrete.
A final note on containers: The sunny sides of a container can heat up so much that roots won’t grow there. See below.
Because of this, I wrap my containers with shade cloth or reed fencing, or I paint the southern half of the container white to reflect sun and cool it.
In general, an avocado tree in a container is likely to need watering more often than one in the ground. That is partly because the potting mixes used don’t usually hold as much water as dirt.
But how often to water depends on the mix used (how much dirt does it contain?), how big the tree is relative to its container, and how sunny and windy it is.
One avocado nursery owner told me they water their avocados in containers every day in summer and sometimes twice per day while in winter whenever there is no rain they still water almost every day.
I don’t water my container trees quite that often. I water every 1-2 days in summer. How to know when to water an avocado tree in a pot? I lift the container to feel the weight. If it’s relatively heavy, then there is still a lot of water inside. If it’s light, then I need to add water. (Of course, this only works for smaller pots.)
You can water by hand or you can use drip emitters. I use drip on some of my potted avocados, and so do some nurseries.
Varieties for containers
Which avocado variety is best to grow in a container? If you’re looking to get fruit from the tree, then I would go with a precocious variety, for that would be one that will start fruiting while the tree is still small. Precocious avocado varieties include Reed, GEM, Gwen, and Lamb.
Pinkerton is precocious but it doesn’t fruit well unless there is another avocado variety nearby, in my experience. So I would only choose Pinkerton if I were growing more than one variety.
Hass is not as precocious as the varieties above but can certainly still fruit while in a container. You have seen evidence of that in the photos above. Here’s one more:
If I were getting really deliberate about growing a fruiting avocado tree in a container, then I would also select a rootstock that tends to induce bearing at a young age. For seedling rootstocks, I would try Gwen or Pinkerton. For clonal rootstocks, I would try Dusa or Ben Ya’acov 1 (VC66). But I don’t think the choice of rootstock is critical.
I leave you with this tree in the ground in my yard that I think could have been a good container tree. It is a Gwen that I grafted onto a Gwen seedling rootstock. It is only as tall as me today, and yet it set 35 avocados this spring.
I hope your container avocado trees are even more fruitful.
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