hi would you please help me what's wrong with my zz plant... its leaves are rolling as you see in pictures.i water it very carefully but it was started 1 month ago,after that i repot it. some roots rotted and i removed them and the tubers(potato) got wrinkle and the new sprout is also didn`t unfurl for a long time since it appear in a pot. i fertilized it with 20 20 20 but after this event i stop it. now what should i do? i should wait? i really appreciate to help me
Leaves curl, because they are trying to conserve water. Plants that have rotted roots can not provide the plant with adequate water, this does not mean you would increase the amount of water. You need to allow the plant time to grow roots before you will see a difference in the leaves. Overall the plant does not look too bad. With time the roots with grow back. Only give he plant as much water as it can take up with the new roots. Dumping lots of water into a pot with no roots, just allows water to stay. You need to provide it with just enough to keep those new roots moist, but not wet. It may take months before you see a difference in the leaves. You might even loose some leaves during this time. As long as you are being wise about the amount of water you are providing the plant will recover.
Fertiliser is not needed at this time. There are enough root too absorb much of this food. You do not want to encourage the plant to grow leaves at this point. If anything, you could have provided some bone meal. This is a natural form of phosphorus, the nutrient needed to grow healthy roots. Avoid other forms of fertiliser at this time. If you are in the Northern Hemisphere this is the wrong time of the year to give food anyway. I know you have already have given some fertiliser already. That will not hurt the plant, but it is not helpful either. But, since you have already given it some phosphorous, the middle number, bone meal is not needed.