Plants are only being repotted after the old pot is completely rooted and has become too small. You will notice that when you have to water the plant more frequently than usual because there is not enough earth in the pot anymore that absorbs the water. Choose a pot that is 2 or 3 sizes bigger than the old one for repotting. For palm trees it would be wise to use a pot that is rather high than wide, since the roots of these plants grow rather deep than spreading wide. Repotting is usually due every 2 to 3 years with normal growth. Some plants may have more sensitive roots (for example palm trees) than others, so make sure not to cut off too many root springs while repotting and also restrain from giving fertilizer for 2 to 3 weeks afterwards.
Commercial seeding compost is often made of peat, a resource that is being viewed critically from a nature conservation perspective. Peat comes