What are the dry parts & yellow marks?

The dry patches and yellow discoloration on your plant's leaves are typically indicators of watering issues.

Symptoms

Common causes

The most common cause of this is overwatering. In particular, it can occur as a result of a lack of drainage in your plants pot, or because the plant first dried up too much and then was overwatered.

This can seem counterintuitive, but when a plant hasn’t been watered for a long time and completely dries up, it can actually cause more damage to add a lot of water all at once. In severe cases, the drought may have damaged the finer root threads too much, making them unable to absorb water once watered again.

What to think about

As for poor drainage, it is always a good idea to ensure that your plant pot has drainage holes at the bottom in order to help prevent root rot. Drainage holes lower the risk of overwatering but it can't keep the soil from getting saturated with water. It's still possible to overwater plants in pots with drainage holes.

Choosing the correct pot size and soil type can help prevent this. Make sure that the pot is an appropriate size - if your plant is planted in a pot that is too small, the roots may not have enough room, which can affect their ability to take up water. A pot that's too large will have an increased risk of overwatering.