Preserving the taproot in containers? To cut or not cut?

[djseaquist]

I have been reading from arborists & others that the taproot is not that special. Many plants survived just fine with a cut taproot. In fact, I heard most trees' taproot will either be indistinguishable or choked out by the lateral roots. [There are a few exceptions, like Mesquite (Prosopis sp.) with crazy long taproots looking for groundwater].

However, I noticed for propagation some plants do better with deeper pots. Growing Sapote (Sapotaceae) seeds do much better in deep treepots (9 or 14 inch), at least during their early life. Other plants could benefit from deeper pots so they don't get deformed roots later on.

But I'm not sure about deep treepots for bigger/older plants are worth it since those containers can be expensive!

Thoughts?

[djseaquist]

I'm also curious if anyone regularly root prunes their container plants.

[elouicious]

there was an old forum member on here, bsbullie, who swore that mangoes grown in containers- or even those that got a "J" root from growing in a pot then being put in the ground would produce inferior fruit and often die-

When talking with my arborist uncle he said the same thing you heard- basically "who cares about the tap root?"

I have never delved into root pruning- but some of the most successful container growers (i.e. Theme in Texas) seem to do it religiously.

I have noticed that trees tend to do better if started in tree pots (surprise surprise) but I think from that point it doesnt matter so much (i.e. up-pot to a regular 5gal)

Note this is different than root girdling- which is another problem

[Daintree]

I am in Idaho, so everything I have is in my heated greenhouse. They are all in pots, over 170 plants, over 80 species. Almost all are tropical fruit trees or bushes, and none have a taproot.
I usually cut the taproot when I pot up and the root is hitting the bottom of the pot and starting to “J”. I like to wait until there are a lot of lateral roots, then off it comes. I’d say by the time they are in 3 gallon pots, nothing has a taproot. They get nutrition from the young roots and root hairs anyway.

Carolyn

[BP]

I think its a timing and species dependent thing. Budswell before things leaf out is good for dormant stuff, no idea how to apply to tropical trees yet. I have bad luck trying to force things in smaller pots, early in its life. As above as below, the deeper tree pots have made a big difference for me for early growth. I've read on bonsainut from pros there that you can do a lot of taproot work extremely early on say acers. I have not had success with this. I think you're able to do rootwork once flat laterals are established for feeding. Then I believe you can start sawing off lower root sections on repotting. People will encourage high flat rooting through tricks like a flat tile with a hole drilled in it over the taproot, girdling it and forcing it to root flat over the tile, enabling it to be in less deep pots while building up roots, cutting below the tile later. J rooting is known to be real bad. Id probably just defer to whatever Carolyn is doing haha she seems like shes got it going on in her set up. Lived experience is where its at

[BP]

I am in Idaho, so everything I have is in my heated greenhouse. They are all in pots, over 170 plants, over 80 species. Almost all are tropical fruit trees or bushes, and none have a taproot.
I usually cut the taproot when I pot up and the root is hitting the bottom of the pot and starting to “J”. I like to wait until there are a lot of lateral roots, then off it comes. I’d say by the time they are in 3 gallon pots, nothing has a taproot. They get nutrition from the young roots and root hairs anyway.

Carolyn

Sounds awesome, what do you like to use for your container medium and do you have any particular fertilizer you like? Do you have any pics of your greenhouse it sounds incredible!

[Lumi-Ukko]

Since I grow a lot in containers*, I often get the taproot coming through the bottom and establishing in the ground before I get round to up-potting them. When I do up-pot them, I invariably have to break the tap root from the ground and in my experience, if the tree is healthy, it doesn't affect it too much. What I have noticed since I've moved over to growing mostly in air-pots is that the root structure of side roots is much better and probably helps offset any damage/trimming to the tap root.

*Necessary until they go in ground at the new place I have.

[fishie]

Since I grow a lot in containers*, I often get the taproot coming through the bottom and establishing in the ground before I get round to up-potting them. When I do up-pot them, I invariably have to break the tap root from the ground and in my experience, if the tree is healthy, it doesn't affect it too much. What I have noticed since I've moved over to growing mostly in air-pots is that the root structure of side roots is much better and probably helps offset any damage/trimming to the tap root.

*Necessary until they go in ground at the new place I have.

I have a similar experience as you. For me, roots are roots, regardless if they are the tap root or not. Eventually more roots will form in one way or another. It's more about the overall mass of the roots, rather than it being a tap root or not.

[brian]

I root prune my container trees, including at least one pouteria.  Only with garcinias do I make an effort to use long skinny containers and preserve the taproot, simply because everybody says it is important. 

[roblack]

G. mangostana in particular is sensitive to taproot damage, when young. Other garcinias appear much more forgiving. Having a taproot for outdoor/in-ground plants certainly can help with stability of the plant, and enduring periods of low rainfall.

[Daintree]

Sounds awesome, what do you like to use for your container medium and do you have any particular fertilizer you like? Do you have any pics of your greenhouse it sounds incredible!

Sure! Here are a bunch that I just ran out and snapped. It is still dark out and the lights are on, so no reflection from the sun makes it look really pretty in there. I took the outdoor shot the other day. We named it Daintree after our favorite rainforest vacation spot in Australia.

As far as potting mix, I know everyone has their favorites, but I use raised bed and potting mix from Home Depot, cut down with about 1/3 to 1/2 perlite. We have a perlite mine in Idaho so I can get 2 CF bags pretty cheap.  I also like to add Turface MVP, which is hardened clay granules, but it is more expensive.  My big thing is drainage, drainage, drainage. Everything, from Bat Flowers to cactus gets the same mix, I water everyone at the same time, and each pot gets more or less, or skipped that week, based on their needs.

For fertilizer, I use a complete synthetic liquid fertilizer, since no matter what I have added to potting mix, it is still very inert and does not build enough microorganisms to digest the organic stuff (I did a Master Gardener project where I spent a ton of time and money growing plants in different mediums and amendments, then sent it out to a lab). The plants can't tell the difference, it is easy to apply and I see really fast results if I am trying to correct a problem. And really, they do fine without symbiotic soil microbes, until they are stressed. And my leafy kids live a life of stress-free luxury...

My favorite fertilizer right now is Dyna-GRO Foliage Pro. It just got bought out by SuperThrive, so I have to be careful to grab the right product when I buy it.  It is totally complete, suitable for hydroponics.  the other thing I have used is Miracle-Gro.  It is complete except for Cal-Mag, so I just add that.

My greenhouse is 700 SF. Would have been bigger but I ran out of yard  . I have gardening clubs, Master Gardeners, college horticulture groups etc. through it all the time. I get so out of control with my plantings that I always warn people that if they see a jaguar in the underbrush to just play dead...

The wonderful deck and pergola that my hubby built


The double entry to keep the birds from escaping


The seating area, The Laughing Impala Pub




One of my Bourke's grasskeets, Hei-Hei


Plants...


My very messy potting table and storage area


The "nursery", with bird netting


Darned monsteras taking over, again...


Cacao trees on the left. Don't get many pods because I have to hand pollinate. Takes tweezers and a jewelers loupe.


Looking towards the back wall


Miracle berry bushes. The tallest one is 5 ft. Trying to air layer them.


Miracle berries. I eat them as I work out there.


My jabos just finished fruiting


Bat flowers on the right, the watering pond that I heat in the winter, and more darned man-eating monsteras


Vanilla planifolia.  I just composted about 50 feet of it. Another thing that gets out of control. Ok, actually everything gets out of control...


Noni. Brought the seeds back from Hawaii after eating the fruit hunched over a trashcan in a park in Honolulu. A passing lady looked at me and said "those are SO disgusting! How can you eat them???"


Coffee.  I used to process it but it is too much of a pain. Now I just plant the seeds and sell small, fruiting bushes. Get a lot of repeat customers because they always manage to kill them.


Marula trees, and Coco, another Bourke's grasskeet


Jewel, my male Splendid grasskeet

[MasOlas]

"I get so out of control with my plantings that I always warn people that if they see a jaguar in the underbrush to just play dead..."

  Atsa a good un, ya!

[NewGen]

Daintree,
That's an amazing setup you have there, so jealous.
I have a 6 x 10 polycarbonate GH from Harbor Freight. I'm in central CA, where the cold months get down to mid 30s. I move Annona squamosa, Muntingia calaburas, and some jackfruit seedlings there when it's cold, like next month. Couple  problems I have every year: ants in the soil  and spider mites. Do you have these issues? What temperatures do you maintain your GH at? I assume yours has good ventilation?
Thanks!

[Daintree]

I have lots of ants, but they don’t bother me because they are not the stinging kind. They aerate the soil with their tunnels, and none of my plants are delicate enough to be affected by them. I never have aphids, so I guess they are not the kind that farm them.
As for spider mites, man I hate those! I have to keep on top of them all the time, rotating my miticides.
I keep my temps above 55 all year because of the cacao, and have ceiling fans every ten ft. I point them down in the winter, and straight ahead in the summer so they help the intake and exhaust fans.
Two gas wall heaters, one at each end.

[BP]

Sounds awesome, what do you like to use for your container medium and do you have any particular fertilizer you like? Do you have any pics of your greenhouse it sounds incredible!

Sure! Here are a bunch that I just ran out and snapped. It is still dark out and the lights are on, so no reflection from the sun makes it look really pretty in there. I took the outdoor shot the other day. We named it Daintree after our favorite rainforest vacation spot in Australia.

As far as potting mix, I know everyone has their favorites, but I use raised bed and potting mix from Home Depot, cut down with about 1/3 to 1/2 perlite. We have a perlite mine in Idaho so I can get 2 CF bags pretty cheap.  I also like to add Turface MVP, which is hardened clay granules, but it is more expensive.  My big thing is drainage, drainage, drainage. Everything, from Bat Flowers to cactus gets the same mix, I water everyone at the same time, and each pot gets more or less, or skipped that week, based on their needs.

For fertilizer, I use a complete synthetic liquid fertilizer, since no matter what I have added to potting mix, it is still very inert and does not build enough microorganisms to digest the organic stuff (I did a Master Gardener project where I spent a ton of time and money growing plants in different mediums and amendments, then sent it out to a lab). The plants can't tell the difference, it is easy to apply and I see really fast results if I am trying to correct a problem. And really, they do fine without symbiotic soil microbes, until they are stressed. And my leafy kids live a life of stress-free luxury...

My favorite fertilizer right now is Dyna-GRO Foliage Pro. It just got bought out by SuperThrive, so I have to be careful to grab the right product when I buy it.  It is totally complete, suitable for hydroponics.  the other thing I have used is Miracle-Gro.  It is complete except for Cal-Mag, so I just add that.

My greenhouse is 700 SF. Would have been bigger but I ran out of yard  . I have gardening clubs, Master Gardeners, college horticulture groups etc. through it all the time. I get so out of control with my plantings that I always warn people that if they see a jaguar in the underbrush to just play dead...

Shortened the quote a bit so I wouldnt repost everything again but WOW what a setup!!! Absolutely fantastic I would spend so much time in there, thanks for sharing! Great tips as well

[FL Boy]

Two gas wall heaters, one at each end.

I noticed your heaters and thought two byproducts of un-vented NG or propane combustion are beneficial in your winter greenhouse.  Water vapor to maintain humidity, and carbon dioxide which aids in plant health and vigor.  Nice setup and beautiful plants!

[brian]

I also run unvented gas heaters in my greenhouse, and haven't had any issues.  My fear was ethylene gas byproduct causing issues, but as far as I can tell no plants are affected by it.  I have carbon mono and dioxide sensors - the co alarm has never gone off and the co2 gets to around 10,000ppm (400 is normal) but 10k is still within OSHA limits

[MasOlas]

As a site safety and health officer on large government construction projects, I can appreciate a man quoting OSHA. Nobody will ever look out for you better than you. Stay safe out there!

[Daintree]

Yes, I do not have to run my misters in the winter. Love those cheap, Home Depot blue flame heaters! And they are plumbed for natural gas, which is way cheaper than propane here.

[Avofan]

I think for subtropical like mango, avocado, sapote they are “jungle” plants and want a sandy medium that’s inert because it’s like the depleted soil of a competitive biome. I also noticed they really like the tall pots, same concept -imagine the jungle, they want to search for water and to get a foothold.
I have most experience with avocado seeds and about 25% don’t have a taproot. Maybe it’s a simple recessive trait. I imagine if a seed fell on top of a rock with barely any soil, it would be better suited with many tentacles to grab what’s there instead of one big taproot

[ScottR]

Carolyn, do you have THE SMALL ARGENTINE ants ? You don't get soft or hard brown scale on your plants? That's my problem!!