I recently discovered that my cactus has been under-watered!! So I started watering it by thoroughly saturating the soil by leaving it in a bucket of water for about an 1.5 hours when the soil was dry (have done it twice now most recently 2 days ago and 8 days after its last bath the soil was completely dry). I let it sit until the soil feels moist on top. It takes about 6 days for most of the soil to dry out then another 2 to get completely dry again. Well the results are great except only one cactus seems to be benefiting....pictures of this are the two cactus that are side by side, one picture if from sometime in July, the second August 9th the day of their first real bath, and second is from today.

Second question is I have a Cereus Peruvian Apple cactus that just looks plain ole weird. It was also growing a baby and was under-watered so it got too spindly and flopped over so I cut it off and a new baby started growing from that cut (the cactus cutting is doing fine btw). It grew exponentially. First picture of it is from the first week of July, second from August 14th, then the last two from today. Lately it has stopped looking so swollen and the skin looks almost wrinkly and it seems to be leaving. I started watering this cactus properly the same time as the other cacti. I don't know if I should just let it keep doing it's thing or if I'm risking it flopping over like the other baby. Am I doing something wrong? I recently got a cactus fertilizer should I fertilize them? Thanks in advance!

Growing spindly and flopping over are not a sign of underwatering, but rather, a sign of insufficient light. I suspect your new watering regimen (combined with poor light) has caused root rot.

DaisyI said:Growing spindly and flopping over are not a sign of underwatering, but rather, a sign of insufficient light. I suspect your new watering regimen (combined with poor light) has caused root rot.

I agree.

DaisyI said:Growing spindly and flopping over are not a sign of underwatering, but rather, a sign of insufficient light. I suspect your new watering regimen (combined with poor light) has caused root rot.

Is that for both cactuses? They are both in bright south facing windows and I let them hang out outside for a few hours each day to get some west facing light as well, I can't see how they could get that much more light. The cactus baby that was growing spindly before is not the one pictured and it grew with absolutely no water (the cactus offshoot pictured in this post also grew as it is with mostly know water). Do you say it has root rot because of the skin? What are your suggestions? I just started watering them like that because someone who has a bunch of cactuses told me to. I'm gonna be really heart broken if I lose both cactuses. Please tell me how to remedy the situation.

Here are the roots of the Cereus cactus. It doesn't look like there is root rot they look white and healthy but maybe I'm wrong. I repotted it with more sand and pebbles in the soil though so hopefully that improves drainage

hlutzow said:

I agree.

I only started watering the cactuses like this about 16 days ago. I will cease operations immediately though. I would really love some cactus watering knowledge though.

Also would like to add that the soil after its dousing has not been wet for 6 days after watering. More like it stays a little moist 2 inches below the surface and then after a week the soil is completely dry from top to bottom (I use a wooden skewer to test how dry the soil it)

You are right, those roots look healthy. And the soil looks wet. When you repot, don't water for a week or more to allow damaged roots to heal.

Watering to soil saturation is good, soaking for 1.5 hours is bad. When you simply add water, does the soil get completely wet? You can figure that out with your stick by looking for wet and dry patches on it.

Look at the growth of your cactus. The new growth should be as wide or wider than the old growth. If there are narrow spots, those will be weak spots and the cactus will bend or break from the weight of the new growth above it. It could be the wilted wrinkly top just isn't getting enough moisture from the roots because of the narrow little connector piece.

DaisyI said:You are right, those roots look healthy. And the soil looks wet. When you repot, don't water for a week or more to allow damaged roots to heal.

Watering to soil saturation is good, soaking for 1.5 hours is bad. When you simply add water, does the soil get completely wet? You can figure that out with your stick by looking for wet and dry patches on it.

Look at the growth of your cactus. The new growth should be as wide or wider than the old growth. If there are narrow spots, those will be weak spots and the cactus will bend or break from the weight of the new growth above it. It could be the wilted wrinkly top just isn't getting enough moisture from the roots because of the narrow little connector piece.

That makes a lot of sense! I was thinking the too might just not be getting enough water because the piece it is growing off is so small. My friend who gave me the cactus told me to not water from the top but maybe it's ok as long as it drains and dries quickly? Before I'd just fill up it's little basin but that wasn't making the soil even a little damp except for the very bottom so maybe the solution is to give it more frequent small drinks throughout the day when it's watering day. I am thinking that if next week the growth is still looking like it's shriveling I will cut it off and just propegate a new cactus from it.

Second question though....what about my two cacti planted together? One is inflating while the other is shrinking

Cutting the top growth and starting it as a new plant is your best option.
Then you will have a normal looking cactus plant.
Best place to cut it is where the base is smallest. By cutting here the time for it to callus will be quicker and you can get it in a new pot sooner.
If you want more plants from the old base then you should cut an inch or more off the top of the base plant. This will expose new nodes that will push out new growth. If you leave the base alone with the old cut edge it may never sprout new growth.

I would separate the two plants sharing one pot. It is obvious the root systems are not equal. In separate pots they can be watered at different intervals according to their demands. If left together the weaker plant will just keep going downhill.

OrchidBob said:Cutting the top growth and starting it as a new plant is your best option.
Then you will have a normal looking cactus plant.
Best place to cut it is where the base is smallest. By cutting here the time for it to callus will be quicker and you can get it in a new pot sooner.
If you want more plants from the old base then you should cut an inch or more off the top of the base plant. This will expose new nodes that will push out new growth. If you leave the base alone with the old cut edge it may never sprout new growth.

I would separate the two plants sharing one pot. It is obvious the root systems are not equal. In separate pots they can be watered at different intervals according to their demands. If left together the weaker plant will just keep going downhill.

Wow thank you! I cut the big cactus today at the base of the newest growth and then cut roughly an inch off of the old cactus so crossing my fingers it will produce a new baby that will grow more normally. Hopefully there's still enough growing season left.

I'm going to find new smaller pots for the 2 cactuses that are growing at different rates and hopefully the skinny one makes a full recovery! Thank you!

Please allow time for the big cactus cutting to heal (callus) before you pot it up. Most people say a couple of weeks stored in a shady location is enough. The size of the exposed "wound" on this cutting is small since the diameter was small so it should not take long to heal. Larger exposed cuts take considerably longer to heal....sometimes months.
When I pot it up I use bamboo stakes to hold it upright and I do not water for a week or two to encourage rooting. Then I water infrequently since it takes longer for the pot to dry when there are minimal roots to take up the water. So keep to the plan of watering only when necessary (the soil is mostly dry, but never bone dry). New roots do not like to "completely dry out".
That said: Do Not Overwater.
I start my new rooting in shade (bright light), never in full sun. Once the top shows new growth the plant can be moved gradually back into full sun.

OrchidBob said:Please allow time for the big cactus cutting to heal (callus) before you pot it up. Most people say a couple of weeks stored in a shady location is enough. The size of the exposed "wound" on this cutting is small since the diameter was small so it should not take long to heal. Larger exposed cuts take considerably longer to heal....sometimes months.
When I pot it up I use bamboo stakes to hold it upright and I do not water for a week or two to encourage rooting. Then I water infrequently since it takes longer for the pot to dry when there are minimal roots to take up the water. So keep to the plan of watering only when necessary (the soil is mostly dry, but never bone dry). New roots do not like to "completely dry out".
That said: Do Not Overwater.
I start my new rooting in shade (bright light), never in full sun. Once the top shows new growth the plant can be moved gradually back into full sun.

Thank you! That is great advice! I'm sure it will be even slower to root because growing season is ending soon. I have another cactus cutting (the top of that weird middle part in the picture) that I successfully rooted. I didn't see new growth necessarily but it had rooted to the point that I couldn't pull it out of the soil and it seems to be fattening up. Hopefully this new cutting will root just as easily!