Question: I grow two avocado trees in huge pots. I wondered if it would be possible to plant my aloes in the same pots, at the foot of the avocados? That would save a lot of space and it seems to me that the effect would be very attractive. What do you think?
Answer: Your question brought up an interesting thought. Why is it that we traditionally grow each houseplant in an individual pot? After all, we don’t do so outdoors. We regularly mix and match plants in flower boxes and containers, in flower beds as well. Yet with houseplants, it’s usually: one plant per pot, even though there is no logical reason we couldn’t mix houseplants together too: it’s just a question of long-standing habit.
Compatibility is the Issue
Of course, the secret to success with mixed pots is that the plants have to be compatible, with similar or identical needs.
You’d have a hard time keeping a desert cactus, which prefers full sun and soil that dries out thoroughly between waterings, and a maidenhair fern, which prefers moderate to low light and soil that is constantly moist, happy in the same container. Nor should you try planting together strong, invasive plants with slow-growing or fragile ones, plants that need a long period of dry dormancy with plants that grow year-round, plants that require a lot of fertilizer with plants that prefer nutrient-poor soil, nor plants that differ in soil type, temperature, light needs, etc.
There are even allelopathic houseplants (Kalanchoe daigremontiana, for example) that render the soil in which they grow toxic to many other plants and are therefore never good buggy buddies.
That said, there are many houseplants that actually do share many of the same requirements. So many common varieties like or at least tolerate average light, average air humidity and average watering—philodendrons, scheffleras, spathiphyllums, etc.—and therefore, unless they have some other incompatibility, could certainly share a pot.
Nor is there any problem growing most succulents, such as sedums, aeoniums, euphorbias, crassulas and echeverias, in the same pot, since almost all like full sun, tolerate dry air and prefer soil that dries out between waterings. But if you add a desert cactus to the mix, even if this is currently done commercially (unfortunately), it often leads to disaster, as least in the long run. That’s because most cacti really only do well with a long winter dormancy under cool, dry conditions, while “other succulents” usually don’t like things quite that cold and dry.
In other words, combining different plants in one pot is possible, but it can be complicated.
At first glance, the combination you suggest would not seem doable. The avocado (Persea americana) is a tree native to the tropical rainforest (i.e. jungle) and prefers soil that is always at least a bit moist, plus high atmospheric humidity at all times. The medicinal aloe (Aloe vera), on the other hand, comes from an arid environment, where the air is dry and the soil receives no water for months on end. Growing them together would seem to be a really bad idea.
That said, the aloe is an extremely adaptable plant, much more so than the avocado. It’s been grown as a potted plant for almost 6,000 years and seems to have learned to live with human vagaries. Yes, it prefers sun and soil that is on the dry side, but will adapt to medium or even low light and soil that is never totally dry, although you can’t leave it soaking wet for weeks at a time. Although it was designed by nature to tolerate dry air, it doesn’t require it and it won’t react badly to the efforts you put into keeping the much more finicky avocado happy. And both do like warmth year round, so they have at least one thing totally in common.
So yes, I think you could grow both together. It’s a borderline combination, but as long as you watch your watering and let the soil nearly dry out before you water, you ought to be able to let aloes share the big pots of your avocados.