Here is. “cold hardy” avocado grown in Lake Jackson, TX (less than 10 miles from Gulf of Mexico) planted as a seedling in 1989. Froze in February 2021. Sort of survived the 14F freeze. Seedling of mexican race. Fruit not quite as good as a grocery store one but with bigger seeds. Squirrels get most of the fruit. Trunk bigger than two feet across. On the banks of Oyster Creek in my friends back yard. Most mature citrus trees froze including his Panzarella orange and lemon seedlings. A few odd citrus didn’t freeze competely like sunquat. https://www.panzarellacitrus.com/
4 Likes
Thanks! I see he sells seedlings of that tree, though it looks like it might be a few years before it gets big enough to fruit reliably again. Not all Mexican seedlings are equally hardy, so I’m hoping that by trying hundreds from a wide range of allegedly hardy parent trees over the coming years, I’ll find some that are exceptionally hardy. The fact that green stems on some of my trees appear to have survived 15°F in December is very promising.
1 Like
he did sell seedlings but no fruit so far after the freeze
2 Likes
Avocados from John Panzarella’s tree in Lake Jackson circa 2019. The tree is 40+ feet tall and trimmed by the power company. He is 11 miles from the beach and his house is on Oyster Creek. Usually can’t grow avocados this far north but sometimes you get lucky. The tree is a seedling so the variety is Panzarella as they aren’t true from seed. On the small size and with a large pit, but can’t beat the price which is free. This is the first time I happened to be at his house when he had some ready! Squirrels eat lots of them before they are ready. Grocery store cados are Hass and won’t grow in the humid Gulf Coast.
2 Likes
I’ve done quite a few grafts in the greenhouse in the last few weeks, including many of the potted trees that were damaged by the December freeze. This is one that I had presumed dead until I was about to compost the roots and noticed that they seemed pretty alive. This was a Sharwil seedling, so I had definitely not expected it to survive in a pot outside for 18° and 15°F lows, but when I cut it just below the soil line it definitely seems alive enough to attempt a graft (grafted with Northrup):
4 Likes
Got my order of five Zutano seedling rootstocks from Fruitwood:
Grafted one with Teague, one with Stewart, and three with scions that @jsteph00921 collected from a tree growing in a cold valley near Santa Rosa, CA.
4 Likes
It’s cool that you’re doing this trial. I’m growing Persea americana var. drymifolia here a bit south of Seattle. I have half a dozen seedlings planted in ground in my drafty, unheated greenhouse. They’ve been through two winters in ground now and are all still plugging along. Recently I also started a huge batch of additional seedlings from the same mother tree as my original six came from, but I won’t have space to grow them all out. I was gonna just grow them for a year, and evaluate how each seedling comes through the next winter and then compost any poor performers and sell the rest.
2 Likes
I’d be happy to swap some seedlings if you want at any time! My most recent seedlings are from Duke, Aravaipa, and Mexicola.
My in-ground greenhouse trees are grafted with Duke, Aravaipa, Royal-Wright, Joey, Brazos Belle, Jade, and Stewart. Out of those, Duke will be opening its first flowers any day now, and Royal-Wright and Aravaipa both have a few flower buds just starting to swell and open. I’m not really expecting any fruit set this year, but fingers crossed!
3 Likes
@swincher Thanks. I’ve used up my available space for in ground avocados at this point, but once my current in ground trees get old enough to fruit perhaps any that become culls could be used as rootstock for grafting some other seedlings onto.
I suppose one of my major selection criteria will be that my trees need to be able to produce well while being kept pruned into bushes rather than allowed to grow as trees since they will need some (very minimal) winter protection here. For context, where I’m at I’ve found seedlings from ‘Hass’ avocadoes can overwinter in my greenhouse only as die back perennials with the root surviving and resprouting each year, but the top growth dying back. My var. drymifolia seedlings under the same conditions do not die back and so far do not even drop their leaves.
2 Likes
My understanding is that most grafted avocados can be pruned to 8-10 ft shrubs and still produce satisfactorily. For seedlings, though, I’m not sure how that will impact when/whether they first flower. Seedlings supposedly begin to flower based on the size of the tree, rather than age, so it might be best to avoid aggressive pruning until after it starts flowering?
Out of the ~30 first-year drymifolia seedlings I planted out without any protection here in 8b (borderline 9a, less than a mile from Puget Sound at ~300 ft elevation), almost all of them survived that intense freeze in December, some with their main trunk alive and others only a few inches alive above the ground. The snow cover helped a lot, I think, with this Mexicola seedling even keeping some lower leaves that were under snow (it was topped in the fall when it went in the ground, so it only lost the new shoots that had barely hardened off):
Do you know the genealogy of the mother tree of your seedlings? Is it a named variety, or seed-grown? What kind of cold does it encounter where it’s growing? If you don’t want to swap, I’d also gladly purchase some of your seedlings, even the less vigorous ones. I’d also be interested in scionwood from the mother tree if it’s not a named variety. My goal here is to start with the widest possible genetic base for breeding.
1 Like
It looks like you’re almost a full zone warmer than me. I’m 8a technically, but hesistate to grow anything that’s not rated hardy to at least zone 7 based on my experiences with some zone 8 plants not always overwintering reliably here.
The mother tree is growing at my friend’s sister’s house in Northern California. I’m not sure what the average winter lows are, but from what I understand the tree is very large and heavily productive. We know that it’s var. drymifolia based off its characteristics and that of its seedlings (thin skin, anise scented leaves, good hardiness), but we don’t know if it was originally a seedling or a grafted tree as it was already well established on the property before the current owner acquired it. The skin is very thin and I have eaten many of them without pealing or only partially peeled. The texture is soft, but not mushy so it makes good avocado salads when chopped up since the pieces hold their shape.
Here are the fruit from the mother tree:
I’d like to keep all the current seedlings until next spring just to make sure they’re all off to a good start, but we should keep in touch. Although I was planning to sell them, I’d be happy to let you come take some of them next year as a gift since you’re doing good work. Maybe just share back scion to me if any of the seedlings end up being outstanding enough to be worthy of cloning.
6 Likes
That doesn’t look like any of the main named cultivars I’ve seen the fruits of, so I’d guess it’s a seedling tree. Is there any chance they would be willing to sell some cuttings of the mother tree? Very unique little fruit, I’d love to have that grafted on one of my greenhouse trees to cross with my other cultivars.
Sounds great! I’m planning to do this project as a decentralized model where I’ll look for neighbors willing to let me plant trees where I can observe them and take cuttings, so I’d be happy to give you scions or grafted trees of anything I’m growing, any time you might need them! My hope is within a few years my greenhouse trees will be producing dozens or even hundreds of seeds per year that cross over a dozen different hardy cultivars.
2 Likes
The closest looking cultivar I can find in the UC collection is Walter Hole (one of my recent additions), but it doesn’t really look like the same fruit:
2 Likes
I couldn’t help but think that perhaps it was just a random seedling used as a rootstock years ago that suckered from the roots after the grafted top died. I’ve read that some producers like to use var. drymifolia seedlings as rootstock.
That said, the ‘Walter Hole’ picture you posted does look very much like it.
2 Likes
Since I have grafts of Walter Hole, I’d be able to compare things like leaf color/shape and stem coloration, which should nail down whether it’s the same.
2 Likes
Been a little while since I posted a more comprehensive update, so here goes!
New seeds/seedlings
So far this winter I’ve started these seeds:
- 12x Duke
- 7x Aravaipa
- 10x Mexicola
- 11x Royal-Wright
- 20x Bacon
I’ve also purchased 16 Zutano seedling rootstocks from Fruitwood Nursery.
New grafted varieties added
I’ve added 7 cultivars from the UC collection (Teague, 3-1-1, Walter Hole, Ganter, Stewart, Mayo, and Northrup), two Mexican avocado trees of unknown lineage (maybe grafted, maybe seed-grown), and just got scionwood today from @Marta of Long South Gate (and will be grafting that tomorrow).
I did all also graft scionwood from one of the outdoor seedlings onto a greenhouse tree, and that is pushing nicely now:
Greenhouse trees
Duke is flowering prolifically on both of the first-year grafts on in-ground greenhouse trees, while Aravaipa and Royal-Wright are each flowering on just one branch. None of the other grafts are flowering. The ones that are flowering are just getting started, so no idea yet as far as any fruit set. Wouldn’t be surprised if the trees abort any that do set, though, as the trees are still too small.
Outdoor trees
The outdoor trees are all still pretty much dormant, so we’ll have to wait to see which ones will recover from the December freeze and which will succumb. Mostly they still look to be alive near the ground, with a few seemingly ok further up the trunks, like the grafted Joey tree and a couple of the Mexicola Grande seedlings. Here are a couple charts showing the two main cold snaps they’ve endured:
Here’s one for the entire winter, you can see a few other milder frosts but nothing else severe:
Upcoming
Once the outdoor trees start waking up, I’ll do some more grafting onto things that were killed to the ground but had their roots survive. Other than that, nothing big on the horizon, just more transplanting, seed starting, and grafting as seedlings get big enough. Will do a limited distribution of trees locally this summer, but hoping to have a bigger wave of them in spring/summer 2023.
6 Likes
One of the West Indian (Lula) rootstocks that surprisingly survived the December freeze got some new grafts today:
Ditto for a Bacon seedling rootstock that lost its graft in the freeze:
Both are under cover to warm them on sunny days and protect them on clear nights.
4 Likes
I got 10 more Zutano seedling rootstocks from Fruitwood Nursery yesterday:
I’ve already grafted onto 7 of them, the last three will have to wait until tomorrow, which will include any special requests from @J42 and a neighbor on my street who’s joining in the experiment.
4 Likes
I admire your determination, but I’ve killed a handful here in the Bay Area CA and I have a MUCH more suitable climate. Hot and dry for 9-10 months a year. And dry winters.
Good luck.
4 Likes
Thanks! I fully expect to kill a significant percentage of the trees, and perhaps even all of them, but I’d like to try a few hundred seedlings at least, from at least a few dozen of the more hardy cultivars, before I give up.
And even in that worst case scenario, my greenhouse trees have done very well so far, so I will have some interesting multi-graft trees that should produce a nice little crop of avocados.
7 Likes