Plant roots when repotting

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jerrytheplater
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Plant roots when repotting

Post by jerrytheplater »

I'd like thoughts on the subject of plant roots when repotting.

Cacti need to be dried out for multiple days to weeks after removing them from their soil to allow the roots to callous and heal. This is pretty much common knowledge. Obviously they need this.

Does this hold true for all succulents, only some, maybe none? I'm wondering about Euphorbia from Madagascar. Mesembs from South Africa.

I know when transplanting flowering perennials, trees, and shrubs you have to keep the roots moist while working with them and get them in the ground/pots ASAP. Much different than cacti.

African violets need constant moisture in the air once the plant has had a major repotting. They are not succulents and have no water storage ability-I guess this is the reason they need the care they do.
Jerry Smith
Bloomingdale, NJ
45 inches (114 cm) rain equivalent per year, approx. evenly spread per month
2012 USDA Hardiness Zone 6b: -5F to OF (-20C to -18C) min.
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greenknight
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Location: SW Washington State zone 8b

Re: Plant roots when repotting

Post by greenknight »

I would treat all succulents the same in this regard. Non-succulents, as you say, have no water storage so they have to be kept moist.

With succulents, it's most important to leave them dry after repotting - you don't want them sitting in a pot of saturated mix when the roots haven't yet healed. Unpotting isn't the end of the damage, potting them is going to cause some damage, too. Of course, removing all the old mix from the roots causes much more extensive damage, so it's a good idea to leave them bare root for a while to heal this.

If I'm not changing them to a different mix I usually don't remove all the old mix - just free up the roots on the ouside of the root ball and inspect them, if there are no problems I repot immediately. Changing all the soil every time is more time-consuming and costly, and not really necessary. Eventually you should replace all that old mix with fresh - sooner if using purlite, which breaks down faster, but pumice and hard gravel last many years.
Spence :mrgreen:
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jerrytheplater
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Re: Plant roots when repotting

Post by jerrytheplater »

Thanks Spence. I've been wondering why there is such a difference between plants. It has been stareing me in the face and I didn't stop to think about it. Not all plants are succulents.

Regarding the Malagasy Euphorbias, I'm beginning to think I need to water them more than I have and not let them get to the point of shrivelling leaves. I don't want to grow them obesely, but I don't want them anorexic/dehydrated either. I've been way on the anorexic/dehydrated side so far. I think I may have only waited a few days after repotting, rather than a week or more.

I found I have about a gallon of Dry Stall pumice leftover from a purchase from the CT Cactus and Succulent Society in maybe 2009. I sifted it yesterday to remove particles less than 0.100" sq. (my seive size near 1/8"). Forgot I still had the Dry Stall. But, pumice is hard/impossible to get out here cheaply. A 40 lb bag of Dry Stall shipped to me was going to cost $80.00. Way too much.

I've been looking at expanded shale as a possible replacement locally available. The closest producer is in the Albany, NY area called Norlite, but it looks like they are closing due to environmental regulations. Others exist in other states. A local producer of bagged horticultural supplies, Espoma, sells expanded shale as "Soil Perfector" https://www.espoma.com/product/soil-perfector/ I don't know where they are getting their product-maybe it was Norlite. Have not found a source yet-but have not looked really intensely yet. Too busy cleaning out my garage and sorting my potting supplies.

Interesting to see you leave some of the root ball on some plants according to your experianced estimates of its condition. That works if you are using the same potting mix. I don't see it working if you are making huge texture differences like going from big box peat based mixes to mineral mixes. That requires full mix removal from the plant.
Jerry Smith
Bloomingdale, NJ
45 inches (114 cm) rain equivalent per year, approx. evenly spread per month
2012 USDA Hardiness Zone 6b: -5F to OF (-20C to -18C) min.
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greenknight
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Joined: Tue Apr 30, 2013 4:18 am
Location: SW Washington State zone 8b

Re: Plant roots when repotting

Post by greenknight »

jerrytheplater wrote: Thu Oct 03, 2024 2:08 pm
Interesting to see you leave some of the root ball on some plants according to your experianced estimates of its condition. That works if you are using the same potting mix. I don't see it working if you are making huge texture differences like going from big box peat based mixes to mineral mixes. That requires full mix removal from the plant.
Absolutely right. I barely mentioned it, but it should be emphasized - if you're changing to a different potting mix, you need to remove all the old mix. You should do this with any newly-acquired cactus where you don't know exactly what the mix is that it's in. If it's growing in a peat-based mix you should do it as soon as possible.
Spence :mrgreen:
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