A photo would help to see what it is.

Did you water them after you repotted? That could do it. Can you pls. say what kinds of plants?

When you re-pot Cacti or Succulents you should not water them for at least 10 to 14 days to give the roots time to repair themselves after taking them out of the pot. When you star watering after a couple of weeks do it gradually.

I've never had issues with immediate watering of repotted plants, as long as the soil is sufficiently porous. My guess would be that the soil is too water retentive, or the plants are being placed in full sun before they've had time to reroot. Use a porous soil, and keep the plants protected from harsh conditions until they begin growing again.

-Chris

savant,

That's incorrect - several days after repotting is fine for watering.

Yeah in both cases I watered immediately after repotting but did allow the soil to drain. That's helpful though I'll make sure to wait longer to water from now on. I'm not sure what the plant names were but one looked like this

Kalanchoe blossfeldiana variety

In my experiences, waiting to water causes more harm than good. As I stated on a similar post about jades, I've tried waiting, and it causes more leaf wilting and a much longer recovery time. Letting roots dry is not good for any plant, including succulents; they just tolerate it better. The key is not letting the roots stay wet, which is what rots them. The whole root of the problem, pun intended, is in the soil. If you use soil that holds too much moisture, such as bagged peat based mix, including "cactus soil", you are asking for trouble. At the very least, it's best to mix it 50/50 with perlite, but in my opinion that's just putting lipstick on a pig. Using a gritty type mix, which drains well and allows for plenty of aeration to the roots, will make it near impossible to overwater. It also allows you to water right away after a repot, without fear of rot.

Joe

^ Couldn't agree more.

I see the "wait to water" advice perpetuated all the time, and I think it's just a holdover from people trying to grow succulents in poor, water retentive soils. For those that are using gritty soils, there's no reason to withhold water, and doing so is just shooting yourself in the foot. The only time I would wait to water is if I had cut any thick, fleshy roots. And in that case, it's probably better to let them callous over in open air before repotting.

-Chris

But since we don't all grow in gritty mix, I DO think that needs to be allowed for, particularly when advising newbies who aren't using it yet.

The problem is, plant roots shouldn't completely dry out, and withholding water because of one's choice of soil is basically choosing the lesser of two evils. Choice one is to repot into poorly drained soil, then water, risking rot, and choice two is to repot into poorly drained soil and withhold water, lessening the risk of rot, but damaging the fine feeder roots by drying them out. Basically, choosing a poorly drained soil is going to create problems, and I'd much rather advise people, especially those new to the hobby, to understand why it's important to use a well drained, gritty type mix, especially with cacti and succulents.

Joe

Just 'cause I don't use gritty mix, doesn't mean my mix isn't fast draining.

We're going to have to agree to disagree on this one. It's just not a problem, at least not for me & hasn't been for years.

Anecdotal experience aside, any soil composed of particles with a diameter less than 0.1" will support a perched water table. This deprives the roots of necessary gas exchange, and is an inherent compromise. The fact that newly repotted plants cannot be immediately watered without fear of rot is evidence of this compromise.

Some people are able to get good results with peat based soils by employing techniques to deal with the inherent problems of such a soil (techniques such as not watering after repotting, adding copious amounts of perlite, etc), but I think it's a mistake to offer generalized advice based on the assumption that people are going to use a compromised soil. I would rather people understand what makes a good soil, and why different practices are required for different soils.

-Chris

The problem is, I've seen cacti rot & I don't think that's what happened to my plant. Rot doesn't occur & completely kill a plant in two days. My soil mostly consists of the sand and perlite. My plant was fine one day then it looked like this the next (above photo) and I don't think rot could have taken it over that fast. I'm just worried that my other plants might suffer the same fate because I have 4 cacti and 3 succulents planted in the same soil, I just haven't watered them yet.

We don't have enough information to go on yet, but I'm going to make a guess anyway based on your picture. It looks like you had a plant that was fairly small and weak to begin with. That could be from a poor soil, insufficient light, or incorrect watering/fertilizing habits. Repotting it was just the final nail in the coffin, as it was just too weak to handle the additional stress of repotting.

But to really get an idea of what's wrong, we'd need more info. Are these indoor plants? How much light do they get? What kind of pot/soil were they in previously? What are your watering/fertilizing habits? What did the root systems look like when you repotted them? And do you have any pictures of the remaining plants?

-Chris

Sand in a mix basically starves the roots of oxygen, so quite likely that added to the damage. Unless it's COARSE sand, it clogs the air spaces in the mix & on the roots, impeding it from getting oxygen. It's why we often counsel against using sand in C&S mixes.

Rot comes in many different ways & you'd be surprised how it can drop a plant in a couple of days. The ongoing damage down below is not always apparent up above until pooft - it's too late.

Happened to me a couple of weeks ago w/ a Sans., seems I watered once too often while not quite dry & several days later, I turned & saw a dying plant, bummer.

So I have heard the 50/50 perlite and cactus mix. Is that not the best option? It's what I am using now, but my plants don't feel very stable in it.

Different folks use different things. Few of us leave them in mix it came in, that's the worst stuff.

If you just repotted the plants, no, they're not going to feel so stable, they'll need time settle in.

Yeah the plant was weakened from the winter & was still in the same soil it had been in since I bought it, that was the first time I replanted it. It was an indoor plant & wasn't getting enough light. I water the plants pretty infrequently but I've read that in the summer they should be watered once a week. The rest of the plants are surpposed to be indoor but i wasn't sure if they were getting enough sun so when it's warm enough I bring them outside. I don't know anything about fertilizer so I have never used it.

This is the only one I'm a bit worried about because I can never seem to keep succulents alive and healthy & it has a bit of discoloration

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