Sick Holly

Question: Ill holly

I have for years a holly bush plant in the vase on the balcony. Suddenly he started to lose the leaves en masse. Some are dry but most are green. Now it's almost bare. No parasites are visible. What should I do? Thanks.

Answer: Ill holly

Dear Ornella,
since you don't see insects on your holly plant, and I don't know how long you keep your shrub in a pot, I think that the loss of foliage is due to excessive watering, which caused the development of rot, at a radical level. Unfortunately, rots are often subtle diseases, in the sense that they tend to develop after weeks, during which the soil of the pot has remained wet for a long time, with stagnant water. Another reason related to the loss of foliage may be the opposite, or a prolonged lack of water; also in this case, since it is a resistant shrub, it may be that its problems with water became apparent after several weeks of scarce watering, even though in the weeks before the shrub looked luxuriant.
If you think it could be a problem actually related to watering, I remind you how and how much you water a holly in a vase; hollies are well vigorous evergreen shrubs, which bear intense frost, heat and drought; but if placed in pots, it is advisable to pay more attention to the needs of the plant, because it does not have the possibility to enlarge its roots at will, in search of water if placed in dry soil, or in search of air if placed in always damp soil . The ideal is to intervene on watering only when the soil is well dry: just dip a finger in the ground, if it is moist and cool, we postpone watering. There is no rule for when to water: in January we can also water once every 10-12 days, only on the hottest days; instead in April we may have to water about once a week, or even more often if the weather is warm. When watering, it is important to wet the soil well, continuing to supply water until you see it coming out of the drain hole in the bottom of the pot, so we are sure we have wetted all the earth bread.
Other reasons that may have caused the loss of the leaves can be tied to a now exhausted ground, which must be replaced, or to the presence of insect larvae between the roots, which are eating them. I believe that repotting, replacing the whole earth with rich and fresh soil, is an excellent solution.