Thuja are dying little by little

Be glad. Thuja smells bad and reminds of a cemetery. The soil underneath suffers as well.

Reasons for turning brown:
Too wet
Too dry
Overfertilized
De-icing salt on the hedge in winter
Pests

My husband just found such black insects on a plant. Could it be related to that...? Actually, my husband waters every day and the soil was also moist on the dead plants...

Be glad. Thuja stinks and reminds of a cemetery. The soil underneath suffers as well. Reasons for browning: Too wet Too dry Overfertilized Road salt on the hedge in winter Pests

The cemetery look is a matter of taste. So far, we have not noticed any stench either – so we would really like to keep our hedge.

There is aphid infestation on thuja, but it usually does not lead to death. If the soil is too acidic, apply lime. In case of waterlogging, loosen the soil and install drainage. The Cinara would also be bad.

Fortunately, Thuja hedges have been banned here. It was a long, cold, and dry winter. Our new hedges have also suffered greatly due to the dryness in winter. Fertilizer, water, and warmth help now. What is broken is just broken.

Amazing what everyone always has against Thujas, it's the same with [Kirschlorbeer]. Better a green hedge than a fence.