I've never heard of 'Crocus' (as a brand name, rather than a type of plant) but, in seeking an answer to your question, I've just found this on their website:
"All our fully hardy plants are grown ‘hard’, so (unlike plants you may have seen in your local garden centre) they stay outside all through the year. This means they might not look their prettiest when they arrive, particularly if you have placed your order in winter - or if it’s early and they have not yet started to grow. Alternatively,
if you’ve ordered summer-flowering plants in September, they may well have been cut down to encourage fresh new growth. Basically, we will do what’s best for our plants, which means that they will do their best for you. Therefore, please remember, the roots are the most important part of the plant, not the top growth.
This ‘tough love‘ makes the plants very robust, so they can be planted straight out in the garden without any risk of a setback as soon as they arrive – with a couple of exceptions. Never plant when the ground is icy or waterlogged, or during hot dry conditions unless you can water them regularly.
[i]If they can’t be planted straight away, place them in a sheltered place away from bright midday sunshine and wind. A shed or garage may sound ideal, but it’s far too dark. Keep them well watered and get them in the ground as soon as you can.[i]"
Source:
https://img.crocdn.co.uk/images/affiliates/crocus/responsive/landing/about-us/crocus_how_to_plant_guide.pdf
I hope that might help a bit!