Dianthus

Question

Why do the buds dry up just as they commence flowering

Answer 1

This could be a sign of nutrient deficiency or improper watering. Try fertilizing it with a general fertilizer like miracle grow or Osmocote slow release fertilizer for flowering plants. Also the plant may need extra water during bloom periods, but when you water do not do it from above, try to water right at the root zone without getting the flowers and foliage excessively wet. Dianthus flowers can be short lived but deadheading most varieties will help them reblooming. This article should help
https://www.gardeningknowhow.com/ornamental/flowers/dianthus/growing-dianthus-plants.htm