Summer graduation dress for size 18/20 who needs a maxi length

[Mabilu]

I've got a graduation in a couple of weeks and had buried head about getting something to wear- I'm mid 30s, 18-20, 5ft 10
I have horrible post pregnancy varicose veins, so prefer a maxi as it will be too hot to wear tights that cover them
I'm a 'soft autumn' and colours on the gown will be black green and purple
I dress very mumsy normally!

This is a John Lewis but might be sale price elsewhere. Assuming you have a gown, the colour does not show much but will below the gown of course. This is very wearable for numerous occasions.

Have a look at Scarlett and Jo dresses. The Verity style in green is a beautiful dress suitable for a graduation. They are available on their own website and John Lewis.

The John Lewis website has a great filtering system, lots of options in your colours on there.

Are you the graduate or attending as a guest?

Ignore me, I saw you mentioned the colours of the hood. It depends on the vibe at your university. Many will still state that you should wear a dark formal dress and wearing black does mean that your hood stands out for the photos. Something like this

https://www.next.co.uk/style/sv105236/y65480

or https://www.next.co.uk/style/sv213745/e16383

I feel like the trouble is the market is full of polyester, and given it's likely to be warm if prefer a natural fibre
I nearly checked out a phase eight dress reduced to £80 and then checked and it was polyester!

Have you looked at the heatwave dresses thread? There are lots of natural fibre dresses suggested on there and definitely some suitable options.

Last year I wore a dress from Seasalt to my dds graduation. Lovely good quality cotton and midi / maxi length. They have loads.

Have a look at Joanna Hope dresses on Vinted/eBay.

I had a similar situation for a friends wedding, I ended up buying summer tights and my legs were so cool and it covered my varicose veins. I got mine from Tights Tights Tights

sorry forgot to add the link https://www.tightstightstights.co.uk/collections/summer-tights

I know the one I posted is probably polyester but Seasalt and M&S most certainly have cotton. Linen creases but a cotton poplin in a darker colour is forgiving.

These are on M&S web site and cotton.

I can't help with dress suggestions (I know nothing about fashion), but I'd advise trying to avoid thin and/or silky/smooth fabrics. I sometimes work on graduations for a company that hires the gowns, and they are quite heavy, with a lot of gathered weight in the back of the shoulders, and on a silky fabric the gown tends to slide backwards and then the front part of the hood pulls right up under your chin. If you plan to pin the gown or hood to the dress to stop this, it can make holes in thin fabrics. If you're wearing a blouse with buttons, some (not all) of the hoods have a button loop, but if your shirt is worn loose rather than tucked in, it can pull everything up. (Can you tell academic dress was designed for men? )
The hats (mortar boards) fit some head shapes better than others, and will give you 'hat hair'. If your hair is fine or smooth, take hair grips.