Melocatus not taking up water!

[Salazar]

I bought this Melocactus over a month ago, potted it up, watered it once a week and about two weeks ago I noticed the plant is shriveling.

When I first repoted this plant the soil was horrible, pure hard clay, and I removed as much of it as I could along with a good chunk of the root system, which I think was already dead even before I bought it cause there was no resistance when I was removing the old soil.

What should I do to encourage the plant to reestablish itself because summer is predicted to be a week away and even now day time temperatures reach 33°c and above and the plant is drying out more every passing day.

Tnx!

[hegar]

It is very difficult to answer your question, because I cannot see the plant. If you could have photographed it after you took it out of the pot, at least some of us would be able to make some kind of educated guess or even come up with a good diagnosis and a way to take corrective action.
You do say, that the root system was no longer intact. Sometimes, when a cactus is overwatered, it loses its roots.
I have experienced some rather stubborn cactus plants, which rather died, than forming roots. That was even the case when I applied rooting hormone.
The worst thing you can do at this time is to place your rootless cactus into soggy growing medium. That would most likely lead to a rot.
It is odd, that a cactus that has been watered excessively and lost its roots in the process, will exhibit the same symptoms as a plant that has been under-watered and suffering from drought conditions.
Here is some advice about how to salvage an overwatered cactus. I hope, that it is good advice and that your plant will become healthy again.

Harald

Rescuing an over-watered Cactus

Cacti are easy-care houseplants because their feeding and watering needs are extremely low. You can largely ignore them and they still thrive. But if you're a chronic over-watered, cacti may be a source of endless frustration. When your cactus has clearly been over-watered, don't fear -- there is a chance you can save it. If there is no fungal or bacterial rot present, a change of neighborhoods may be enough to get your cactus back on track.
Damage Assessment
If you suspect overwatering and damage, such as soft brown spots, are obvious on the outside of the cactus, un-pot the plant by wrapping a few layers of newspaper around it and tipping the cactus out. Carefully brush the soil from the roots and check them for brown or black areas. Extensive damage may be difficult to fix, but if most of the roots are still white, you're in good shape. Cut away the black and brown roots and leave the cactus out of its pot to dry. If brown or black rot areas are extensive, you will need to re-root the cactus. A cactus that has only been occasionally over-watered will recover without further drama.
Encourage Drainage
When overwatering is a chronic problem, help the cactus to shed as much water as quickly as possible in the future. Select an unglazed clay pot only slightly bigger than the cactus and fill it with a commercial cactus mix. Pot the cactus in the mix gently, so you don't upset its delicate roots. The clay pot will wick away more water from the root zone while the loose cactus mix allows water to drain quickly and completely. You should only plant very large landscape cacti directly in the ground because landscape plantings give you less control over drainage.

Re-rooting
When roots or tissues are extensively damaged from overwatering, use a sharp, clean knife to cut away all the rot from the cactus. Even a small portion of healthy tissue can regenerate a whole plant, but if you leave the rot behind, it may continue to spread. Allow the cactus to dry on the counter for several days until a thick scab forms on the cut sections. Place the remaining cactus section into a clay pot with cactus soil and bury it about 1 inch deep unless there isn't much of the cactus left -- in that case, bury it about halfway. Don't water the cactus for the first week, and only water sparingly after that until new growth appears.
Proper Watering
Once your cactus is repotted and ready for success, correct watering is vital to prevent new problems. Only water cacti when the top 1 to 2 inches of the soil -- depending on the size of the cactus -- is completely dry. Do not water the plant from the bottom and never leave it sitting in a saucer of water. It is much better for cacti to be dry than to be wet -- a good rule of thumb is to water about once every 10 days.

[Salazar]

Thanks!
I'll follow the advice you gave but then again Melocacti are well know to take a long time to reestablish themselves and also for having weak root systems, hope this plant survives.

[Salazar]

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Screenshot_2017-03-28-22-18-41-1.png (319.89 KiB) Viewed 1087 times

This is the plant now, as you can see there aren't any roots left or are very reduced.
The bottom part is starting to discolour a bit, turning a bit brown.
Can I treat this plant as a cutting then?
Anyone with any experience with rooting Melocacti? Please share any information, that'd be super helpful.
Thanks

[Steve Johnson]

I purchased an adult Melo matanzanus at a local cactus & succulent show last May, and I found myself in a similar situation. The following is a really detailed discussion (TMI perhaps?), but this may help:

http://www.cactiguide.com/forum/viewtop ... 26#p326726

Fortunately for you, your Melo is still in the juvenile stage, and therefore not so difficult to reestablish as it would be if it was growing a cephalium. At this point you'd be correct to treat the plant as a cutting, since it pretty much has no roots. Cacti need roots for them to take up water, so don't even think about watering unless and until you can detect the presence of new roots. Here's what I'll recommend for you:

1. Get rid of the dry soil clinging to the Melo's bottom by gently cleaning it off in running water, then let it dry out.

2. Fill the pot with dry mix, and put the plant on top. Periodically check the bottom of the plant and see if you notice the presence of stubby little whitish things. If you do, they'll be the very beginning of new root growth.

3. Although I can't tell you how long this would take, checking every 3-4 weeks is a good idea. Be gentle about it -- if the plant is grabbing into the pot, you'll be ready to follow the procedure for light watering as I described in my link.

Roots don't suddenly grow overnight, so my last recommendation here is -- be patient!

[Salazar]

Thanks!
I really appreciate all the responses.