Cast ne’er a clout
Whether the ‘May’ refers to the plant (crataegus or hawthorn – May) or the month, I grew up with ‘Cast ne’er a clout till May be out’.
A clout probably means ‘coat’ and basically it means don’t put away your winter clothes till either the end of May or when May is in bloom. ‘Clout’ is thought to be Welsh and in Scotland a ‘clootie dumpling’ is a steamed pudding wrapped in a ‘clootie’, meaning cloth.
When I was in the Uk last week and staying in an Air B&B which, as usual, don’t actually supply the second ‘B’, I walked to the nearest garage to get a vital coffee before being picked up to work. And there, in the scruffy roadside was a healthy young hawthorn tree. I have planted hawthorns in my hedge as well as four ornamental ‘Crimson Cloud’ but I was overwhelmed in admiration at the beauty of this tree.
How often we overlook the beauty of native, ‘ordinary’ plants. This one was especially lovely being beside roadworks and lightly mulched with rubbish, the long branches almost weighed down with blossom. Simply beautiful.
I have started to plant out some tender plants, although the hawthorns here are not quite in bloom. They are a few days off flowering but my mulberry, which I always use as a gauge to when it is safe to plant out, is starting to burst into growth. * Having said that the weather looks to be cool under high pressure for the next few days and there is a risk of frost. It will be touch-and-go for the start of the week.
Incidentally, hawthorn has many superstitions associated with it and my grandmother and mother would would never have the blossom in the house, thinking it brings bad luck. It may have been because the flowers are fragrant but a bit ‘dungy’ indoors. In Ireland hawthorns are associated with the fairies so you should not cut them down or incur their wrath. Solitary hawthorns are meeting places of the fairies and if you think this is nonsense just remember the fuss that was caused by the tree beside the M18 in Co Clare that was preserved during the construction in case it incurred the wrath of the little folk.
*A few years ago it did start too early and get caught but it is usually a good measure of when it is safe to plant.
The Biking Gardener 
I suppose that it must be native somewhere. Hawthorn is, of course, exotic here, and considered to be quite European. I just recently purchased two North American hawthorns, though. I almost never purchase anything, but wanted Texas mayhaw and Georgia mayhaw for their fruit.
I have a few others including three C. crus-galli from your neck of the woods (well much further east).
Yes, half a continent away. That was another species I considered acquired, but tried to limit my selection to the two simplest species.
G. crus-galli does well for me also – though it has dreadfully dangerous spines and these have caught my head many times while mowing grass. C. prunifolia is another which does very well here.
Are they grown for fruit, or just as ornamentals?
In the past the fruits of the two native species have been used as food but they are very mealy and not really ‘nice’ – more of a famine food. I am sure that ‘top restaurants’ add them to dishes so they can charge a fortune! I think there is a lot of potential among these and similar genera as food crops and I have a few Polish sorbus that are supposed to be edible but although they flower profusely they have not really fruited yet. The trouble is that most of these need other be ‘preserved’ by making jams or syrups or by using them to flavour alcohol so they are not as healthy as the statistics suggest! A bit like my honey berries which are great and make amazing jam but that means eating lots of sugar!
Well, yes, that is the impression that I get. I got my mayhaps specifically for mayhaw jelly. I do not know if they are good for anything else.
Purely as ornamentals with me – excellent spring blossom, a good set of attractive red fruit and outstanding autumn colour.
I’ve always found that saying a bit mysterious — your explanation really helped connect the dots between folklore and gardening wisdom. It’s so true how May can swing between spring warmth and surprise cold snaps! I’ve learned the hard way not to rush with tender plants. Do you find the risk of late frosts is still strong where you are, even this late in the month?