Good luck with your summer bedding. Alot of people will have already planted it so you wont be alone. If all goes well you will get an early show, if we get a frost your local plant centre will benefit from extra trade !!!!
I am already sick to death of telling customers its to early to plant half hardy annuals.

One local garden centre where I picked up a couple of extra plants has big signs in neon marker saying that all their bedding plants need protection from frost but very hard to think about frost at the moment!

Well, here in London I can count the number of frosts we have had since LAST March on the fingers of one hand (OK, maybe two hands) ...
I have been putting in my summer bedding gradually this month.
That said, I have generally tried to avoid annuals altogether because of climate change and to focus on autumn-planted perennials instead.

One annual which seems quite drought tolerant is 4 o'clock plant (Mirabilis jalapa). They did well in very dry clay last year so I tried planting some from seed, but I have found several self-sown seedlings are coming up, so I didn't need to.

Lori - I must confess that I had not heard of Mirabilis jalapa until it was mentioned on Gardeners' Question Time a few weeks ago. I understand that it has a wonderful scent in the evening. Is that correct? Where did you buy it? As seed? As tubers? As young plants? I would have thought that in London it would grow as a perennial because (I have now taken the trouble to look it up) it is a perennial that is grown as an annual in "cold" areas. Here in north London even my Nicotiana alata has made it through the winter (although, perhaps surprisingly, my marguerites have not).

The annuals I have been planting mostly are wild flowers - what my neighbours would probably call weeds - on the assumption that they are likely to be drought-tolerant and to self-seed.

But I have been wanting to introduce evening fragrance - hence the Nicotiana alata, night-scented stocks and my interest in Mirabilis jalapa. Any other ideas for that?

I've grown Mirabilis jalapa from seed that I got from a friend in America. It is pretty common over there, loves the heat. It develops long tubers and I've seen those for sale over here. It is not very hardy, I lost mine the first winter and I'm far from the coldest part of England. It survives far colder temperatures in the States, so I suspect it doesn't like our winter rains, maybe would do better in Essex. It didn't really thrive for me, not hot enough I suspect. The flowers are pretty, not open long but late afternoon to evening which is a good time for many people.