Advice needed. Just repotted my two dying avocados in Tapla's 5-1-1

2 months ago

last modified: 2 months ago

Hi yall,
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I got these two avocados on a promotion during the summer of 22. One Cold Hardy, and one Haas. They've done just ok the first year, and I know nothing about avocados. I was told to let them be and not even repot them until the next spring. Sounded weird to me, but hey, they were the experts, right?
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So, during the spring of 2023, I contacted the nursery and they gave me very specific instructions as to how to repot them, what to repot them into, and so on. Which I did.
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During the summer of 2023, they started to exhibit some serious brown leaves symptoms. I kept on taking pictures and speaking to their "avocado expert", but he kept on brushing me off, saying it was just some minor sunburn. Ok then.
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After the trees got brought in for the winter, the problem kept on getting worse and worse, until pretty much all leaves had fallen. Again, their "expert" told me it was just the shock of being brought in. Which was cute and all, but I knew something else was up.
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I asked if maybe the soil they sold me could be a little too slow to drain (sometimes it took over 2 weeks for the top 2 inches to dry out), I got brushed off. I asked if (maybe) I should repot the trees in a 511 type mix, again, brushed off.
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Then they told me the reason the leaves were browning and falling (even brand new, baby, leaves, btw), was that there was, and I quote, "too much light". Which is insane in the face of it because they did fine under the same lights the previous winter. Those are LED grow lights, the same lights I've been using on all my fruit trees (Meyers, olive, banana) for over 8 years, and they all love them.
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I was hoping my trees would make it to spring, so I could take them outside and repot them in either gritty mix or 511, but they were not going to make it that long.
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Two weeks ago, the main stem of the Cold Hardy, that had already lost all its leaves, started to brown from the top down, and it was going FAST.
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The Haas had lost many limbs to the black tips disease, and although it's still fighting and constantly making new buds, they start growing and then promptly die.
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This could've have come at a worse time for me. My right wrist and thumb are injured and I can't even lift a cup of coffee. I also knew I couldn't sift anything in my current condition, and that the ingredients of the gritty would be way too heavy for me to handle, let alone the planter. But my trees couldn't wait another minute.
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So, yesterday, I pulled on my big girl's panties, and I repotted them both into 511. I was in tears from the pain by the time I was done.
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I did wick both planters, because I remember reading a post from Al saying if you couldn't sift, then you had to wick. I also watered the crap out of both of them the second my husband brought them back in, and I will keep on doing it daily, since I couldn't soak the bark either, with my wrist. Typically, they would be raised on bricks inside of their saucers, but because I want to make sure they stay hydrated for the first week of two, they are currently not.
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They both had remarkably well developed root systems. Sadly, the Cold Hardy had clear signs of root rot. Not so much the Haas. The soil was also so hardly compacted (albeit wet) that it was very hard for me to depot them, and bare root them.
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I don't know what the root symptoms of fertilizer burn are, but with such a crappy potting medium, I bet that it was an issue as well.
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I now realize I have to unlearn everything these idiots at the nursery taught me about avocados and start over. Meyers and olive trees, I'm very familiar with at this point. I even got a damn banana tree to flower and produce bananas inside my living room (I'll snap pictures later, it looks so cool). But there is surprisingly little information out there on container avocados.
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I've been spending hours and hours researching, but there really isn't much info on avocados. Even the avocado board here, is pretty bare. It wasn't until I found Greenman28 old avocado threads that I regained some hope for my poor trees.
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Emboldened by what I read in one of his posts, I decapitated the Cold Hardy before I repotted it. It probably won't make it. It's on its last legs, it's the wrong season, from greenman28's post I read they generally hate being repotted to begin with. Add the severe pruning, and the root rot, this probably will end it. But at this point, a Hail Mary remains its best chance of comeback.
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The Haas still has more fight left in it, so I have better hope. Still, they've both been through the ringer. Fingers crossed.
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My husband, seeing how distraught I was about this all week, already bought me two more "big" avocado trees for my birthday, that are set to arrive at the end of March. Sadly, he bought them with the same idiots, not knowing any better.
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I'm not sure if I will repot the new trees in 511 or gritty. I've never done gritty. I finally sourced all the ingredients including turface, so I know where to get everything, but I'm still hesitant. I like the longevity aspect of it, but I'm dreading the weight and sifting, which will both be hell on my neck, back and wrist injuries. And my husband is a germophobe, so I'm on my own. I wish I knew of a way to modify the 511 to make it a little heavier (so planters wouldn't fall with the slightest wind), but I wouldn't know where to begin on how to do that. Anyway, that's not going to be an issue until sometimes in April, so I disgress. Right now, my focus is on trying to save Guac and Mole. (Dont look at me, my husband is the one who named them).
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If Al, greenman, Meyermike, or anyone else has some input as to what I should do (or not) at this point, let me know. As Mike will tell you, I listen, and I learn fast.
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Thank you for reading this novel of a thread. God bless.
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Atheen

Featured Answer

tapla (mid-Michigan, USDA z5b-6a)

last month

@Atheen - 7a - in Maryland, USA Two things I've learned when it comes to nursery and greenhouse ops:

1) their focus is on the bottom line ($) and not on the long term effects their care practices have on the plant subsequent to the point in time when the plant is sold. The (previously) conventional process of potting plants up to a larger pot (nursery can) before the plant became rootbound to the point where the root/soil mass can be lifted from the pot intact have been mostly discarded because of the cost of added soil, cost of pot, and particularly because of the cost of labor to properly care for nursery crops. This results in the sealing of many plant's fates due to the effects of root congestion; and, the effects of the new 'labor saving' method results in the sale of a very high % of plants that shouldn't even be sold; this because once a plant has been allowed to become that rootbound, the negative effects are permanent, unless a pair of hands at some point gets into the root mass to correct congestion and problem roots.

2) Very few employees of nursery and greenhouse ops have anything resembling a even a reasonably good working knowledge of A) the impact of root congestion on plant health, growth rate, and the plant's ability to defend itself against insect herbivory and disease pathogens, and B) how to correct the root issues and perform a full repot. Currently, and due to labor costs, extremely few nursery ops pot up in a timely manner, and very precious few do anything about trying to correct a plant that has become extremely rootbound. It has become cheaper to destroy the plant than to correct its congested roots. This is why nursery/greenhouse employees look at you like you have a third eye when you start asking questions about high quality grow media and/or performing full repots. It has, unfortunately, become almost a foreign concept for anyone other than managerial staff, and even if the staff understands what the effects of root congestion are and how to eliminate the issue, no action is taken because of the added work's impact on the bottom line.

I wish I knew of a way to modify the 511 to make it a little heavier (so planters wouldn't fall with the slightest wind), but I wouldn't know where to begin on how to do that. This problem's resolution is actually quite easy. By a pot considerably larger than you think you'll need, and fill the bottom of the pot with bricks or large rocks. This 'ballast' not only provides added weight to help guard against toppling, it also reduces the volume of grow medium CAPABLE of holding excess (perched) water.

For any given soil that supports perched water, the max ht of the perched water column, for that soil, is a constant. IOW, no matter the size or shape of the pot, the max PWT ht will be the same. You can see (below) that 1) roots are reluctant to grow into areas of saturated soil, which leaves roots susceptible to fungi that cause root rot, and 2) when using gravel and other small objects as a "drainage layer", the layer simply raises the PWT to a position higher in the pot than it would be w/o the layer. Obviously, this is highly undesirable.

Using large objects like like bricks/rocks as ballast doesn't cause the same problem. The benefit of using ballast lies in the fact that it displaces grow medium that would normally be 100% saturated w/o raising the ht of the PWT.

If you have a bucket of water filled to the top, then drop a brick into the bucket, a volume of water equal to the displacement of the brick/ballast will overflow the rim of the bucked. On the other hand, if you have a 10x10 bucket with a drain hole filled with a grow medium that is supporting 4" of perched water soil (400 cu in), and you introduce a 2x4x8 brick at the bottom of that container, it will displace 64 cu" of soil saturated with PW. Since you can line the inside of a 10x10 pot with 4 bricks, leaving a hole in the middle of the arrangement, you can displace 256" of saturated soil with only 4 bricks. If you broke 2 additional bricks in half and added them to the bottom, you will have displaced 384 cu in of the 400 cu in capable of holding PW. The key to the bricks working as a ballast instead of a false bottom lies in the fact that there must be a continuous column of soil from the top of the soil line to the bottom of the pot to act as the wick through which the water is FORCED to flow out of the drain hole.

Wicks work well, but items judiciously considered and placed in the pot to serve as ballast work better; and, once the planting is established, the ballast works passively for as long as the planting exists. Use bricks/rocks if you need weight, or an overturned pot/bucket, or empty soda bottles (cap on) if you want to keep things light.