In this video I will explain what a seed is which will help you understand why we need to store them carefully in a cool dry place.

What is a seed?
Propagator Lids

Lids on or lids off?

Compost drying out seed trays will inhibit germination

For the most part seeds sit in the top layer of compost. During late Spring and early Summer the top layer of compost is at more risk of drying out completely making it impossible to rehydrate no matter how much you water. This dry arid environment will signal to the seed that conditions are not right for germination, seedlings might not survive such harsh conditions so the seed remains stubbornly dormant.