Lettuce back-up

I don't seem to be having much success with seeds this year. I sowed a lot of flower seeds (cornflowers, californian poppies, calendula, nigella, poached egg) back in April to fill the gaps in the borders but most are no show. This is pretty disappointing as I was really conscientious about watering all through that hot spell. My beetroot just don't seem to want to come up at all despite two sowings already and my beans (French and runner) are nowhere to be seen. On top of this, my carelessness with my indoor-sown lost lettuce was even more annoying. Still, my pot-sown seeds seem to have been the most successful. Reckon we'll be munching these soon.