Stuart wrote: ↑Mon Sep 06, 2021 8:52 pm
By 'repot' I'm assuming that we're really talking about 'potting on', taking a plant out of its pot, keeping the root ball intact and putting it into a larger pot with a bit more compost. I try to keep it facing the same direction when it goes back into the collection. It can be done at any time but winter is best as it's easier when the compost is dry.
I've never gone for the 'repotting' thing where all the compost is removed - there must be some strange satisfaction in staring at the remaining roots left after the compost has been removed. If there's root mealy it will show on the inside of the pot so there's no point in ripping off all the compost. The only exception is growing in pumice or similar when it's often not possible to keep the root ball intact.
I'll just sit back now and wait for someone to disagree with everything I've just written.
Stuart
I've converted to pumice so I've had to go back to bare roots. Some of the stuff I had to remove from plant roots was unbelivable. One plant was in a material that I could only describe as beach sand mixed with superglue. It was effectively "growing" in a bone dry sandcastle.... almost set like concrete.
The worst stuff to get off is very dry peaty compost and not much grit. The easiest stuff to get off is JI and grit, and that seems to take most of the (usually dead) roots with it too.
One good shake and all the old compost should just mostly fall away. Layering compost isn't a good idea as I don't think water soaks into the middle properly across a boundary line between mixes.
When I did my conversion I found at least 20 different mixes in my collection. None of which are going to react the same way to water. It was a real eye opener to what was going on with the roots and how much water was (or was not) getting into the compost.
So really the best time....? As soon as you get a plant home (assuming it is dry).
I've read in a number of cultivation guides that the best time to repot is when plants are "actively growing".
So is there no disadvantage to repotting plants over winter during their winter rest period, assuming dry compost is used? I'd hate flowering to be disrupted (for example).
SimonT wrote: ↑Mon Sep 06, 2021 10:51 pm
I've read in a number of cultivation guides that the best time to repot is when plants are "actively growing".
I couldn't agree with that although potting during active growth doesn't seem to bother Rebutias at all.
On the other hand I have a Cleistocactus that when repotted, some of the stems seem to stop growing and eventually die. New stems soon take off but the whole plant is setback a year or two. I'd love to know what I'm doing wrong there. Perhaps my green house is just too cold for it over winter and the March repotting is just coincidental.
SimonT wrote: ↑Mon Sep 06, 2021 10:51 pm
So is there no disadvantage to repotting plants over winter during their winter rest period, assuming dry compost is used? I'd hate flowering to be disrupted (for example).
It's hard to get bone dry compost. Growth could be kick started during a warm spell and then BANG!
best time to repot is when plants are "actively growing"
I tend to agree with that with succulents but this would be choicer ones like pachypodium, euphorbia. I wouldn't worry about Haworthia & some of the tougher succulents. Lots of these have fine roots & won't like the disturbance when they are resting, they may find it harder to restart but as Stuart says I tend to pot on not get the roots naked.
Cactus are anytime, winter is often easier as you have more time but I tend to repot if I have time & they need it.
Cleisto like a bit of water in winter
Tina
varied collection of succulents and cacti but I especially like Euphorbia's, Ariocarpus and variegated agaves.
The only cacti I just pot on would be mature Melocactus, or plants that are just too large to handle easily in order to remove the old soil.
Otherwise my potting mix just comes apart by itself whenever I remove a plant from the soil. I just give them a little shake and more or less all the potting mix comes off on its own. The only organic matter I use is coco coir for seedlings and that just shakes off too, otherwise I only use inorganic potting mix.
I usually unpot a whole bunch of plants in one go and repot them as I have time over the following week or two. I'll usually water immediately after repotting and they take off again as if nothing happened. They're tough plants, cacti. Most succulents I'll only leave a few days at most before repotting though.
A couple photos below. I've just given the plants a good shake, or at most beaten the roots carefully against my fingers or palm a few times.
Stuart wrote: ↑Mon Sep 06, 2021 8:52 pm
By 'repot' I'm assuming that we're really talking about 'potting on', taking a plant out of its pot, keeping the root ball intact and putting it into a larger pot with a bit more compost. I try to keep it facing the same direction when it goes back into the collection. It can be done at any time but winter is best as it's easier when the compost is dry.
I've never gone for the 'repotting' thing where all the compost is removed - there must be some strange satisfaction in staring at the remaining roots left after the compost has been removed. If there's root mealy it will show on the inside of the pot so there's no point in ripping off all the compost. The only exception is growing in pumice or similar when it's often not possible to keep the root ball intact.
I'll just sit back now and wait for someone to disagree with everything I've just written.
Stuart
I agree with you. I have experimented over the years with various mixes and the one I like is JI and grit as it falls off nicely when dry. I also do not remove the total mix on my plants as I buy them young from Ralph or Cact Us plus the odd ones from BCSS Sales fb page. They come nicely wrapped in blue roll and newspaper.
My seeds this year have grown at such a rate I have already potted some on. I just keep running out of pots.I will be sorting them out late Autumn into dry JI/grit mix.
My thinking is if the compost falls away nicely by itself then no need to upset any roots by washing them or banging them. But that is the horticulturist in me.
My wife said the other day that if I buy cat litter / clay granules to experiment my mixes then I can go live in the shed
