Wondering if anyone has had success growing avocado trees in inland northern California, or a similar climate. I know they do well in southern California and I’ve also seen some nice trees in northern California areas closer to the coast. But as you go further inland, the summertime humidity drops and temperature shoots up considerably. On hotter days my area is usually around 25-35% humidity and temperatures are often in the 90s F, hitting above 100 for a few days in a row.
My stone fruit and citrus love the heat, but my avocado tree is always suffering. It looks ok until we hit that first ~100F day and then begins dropping a lot of leaves. It’s planted in a spot that gets mostly morning sun, and I even added some temporary shade so it gets no direct light in the afternoon. It’s definitely getting enough water too. It looked pretty sad after our first heat wave of the year, and now after our second heat wave it looks even worse.
Last year it didn’t do much better. It lost pretty much all of its leaves by the end of summer and didn’t leaf out until the next spring.
So my question is- is it worth replacing this tree with a new avocado tree that has more vigor? Maybe a larger one if I can find it? The heat itself does not seem to be the issue based on what I can find online. But low humidity + heat is probably a bigger stress on the tree.
Of all the avocado varieties that I grow, none get significant damage on their leaves unless the temperature reaches over about 105 degrees, as long as the tree is well watered, healthy, and over about knee height. (link)
I’m leaning towards replacing this tree with another avocado and giving it a try next year, but would be great to hear if anyone has had success in a similar climate.
Curious about answers here. Not sure how far island you are. I’m in San Ramon. I don’t have any in-ground yet (still debating the right spot) but I have three trees in pots (two are grafted, and only one of those is taller than 2 feet… Probably 4’) do OK but they’re in pretty heavy shade
For one thing, with that leaf drop (or before?), it looks like you’re getting sunburn so I’d at least suggest whitewashing as much sky/south/west facing sides of branches as possible. My first tree got that and it really stunted back but now that it’s covered, buds emerge pretty quickly to replace the lost leaves.
I know @Marta has had success. That tree looks like it’s under-watered to me. They require lots of water when getting established. Even here in the much cooler PNW I’m giving each outdoor tree a deep soaking (an hour with the hose on a steady drip) at least twice a week, and sometimes I still see them wilt a little before I get to them again. We are in D1 or D2 drought with almost zero soil moisture at the moment.
Edit: It could also be wet feet if you’re definitely watering enough but have poorly draining soil. Too little water and too much water show similar symptoms.
Also your temperatures (95°F+) & humidity (sub-35%) basically match my greenhouse here in summer, and the trees in there are mostly happy as long as I water them deeply a couple times a week.
It’s not just the water. The young trees can get sunburned easily. You will probably need a shade structures if you don’t have a spot that protects the tree from the afternoon sun. I grow multiple cultivsrs in Davis with the first tree planted in 2001.
Sorry to go slightly off-topic @Marta, but I saw Long South Gate fruitlets in that first link and it reminded me I’ve been wanting to check in with you about that one. Have you gotten any fruit from it yet? My greenhouse graft has been growing very vigorously this season after being slower last year, but I’m doubtful it’ll be large enough to hold fruit until 2025. It was one of the few grafts from last year or earlier that didn’t flower at all this spring for me. I’m just curious what the fruit quality is like since I believe you hadn’t tried the fruit yet last time we talked about it.
My trees are just now getting big enough that they should start setting fruit next year, but I’ll be hand pollinating and leaving doors open if they flower late enough in the spring for pollinators to be active. I will also be turning off the heaters next spring to try to delay flowering because I think the overnight low was still too cold this year when they flowered (avocados have ovary development problems below ~50°F), so I had zero fruit set despite lots of hand pollination. The trees were also still a bit small, but have almost doubled in size so far this year.
I don’t remember the fruit quality to be honest. The graft made like 10 fruits and we ate them all. They were not as large as I expected is all I remember. I decided that it’s too early to evaluate
these fruits as they are too small and too many on the graft. The seed is large. I believe I found the pictures on my phone of the fruit collected in December
That seed sure is huge! It is interesting that the neck isn’t as long as in the photos in your original post from the ortet. I wonder if that is partly due to the pollenizer variety, which I know can impact seed shape/size and fruit shape at least a little.
I’ll let you know if mine sets any fruit next year!
The first year for sure they need shade, then it depends on how well they developed the canopy. They can be in the full sun already in the second summer. But only if they have a good canopy that covers all stems and no naked branches exposed to the direct sun.
There’s a few large avocados at the Wolfskill Experimental Orchard in Winters that have been there for many years and rival those I’ve seen in SoCal. At least one is similar to Mexicola, one has pebbled skin and longish fruits, and a few I’ve never seen mature fruit from. But there’s a range of avocado types that will grow in the Central Valley.
In addition to too much sun and lack of water, reflected heat from nearby structures can damage plants. Even if you shade the tree itself, it may be getting enough heat from nearby walls that it’s getting cooked.
That’s a good point and might be contributing to the heat stress here. My avocado is indeed in a spot next to a cinder block retaining wall. I figured it might appreciate the extra winter protection but clearly it’s getting toasted in summer.
Try shading the wall itself, not just the plants in front of it. Last year, I couldn’t figure out why the leaves on a recently planted magnolia were getting burned despite shade cloth and relatively mild temperatures until I realized that the wall behind it is in full sun from 2-4pm. This year I attached the shade cloth to my roof so it forms a canopy over the magnolia and the wall behind it. No burned leaves yet.
There are lots of fantastic avocado trees all over inland Northern California. Take a trip to Sacramento, Modesto, Stockton and even as far north as Oroville and you’ll find massive avocado trees growing and producing.
