Its impossible to be accurate as it depends on what you sow. Look at the flowers you want and check on their height planting distances etc and do a 'mind map' of what you want where are go from there. If you are sowing dierect then expect at least a 1/3 to fail to germinate, then a 1/3 to get eaten.......

good luck

When I first started gardening, I used lots of annuals in a border. Seaburn's right, it's impossible to tell, not to mention I couldn't tell the difference between the annuals I'd sown and weed seedlings, so ended up carefully tending a border half full of weeds. The next year, I sowed all the seeds in trays in a cold frame in very early March, then pricked them out and planted them when they were big enough exactly where I wanted them. A lot of fuss for hardy annuals, but I got much better results.

Thanks bamboo & seaburn. Thought it was bit of a tall ask! I plan to sow in the way you suggest bamboo and have already bought the seed trays etc. Guess this first year will just be trial and error. Thanks again to you both.

Nigella (love in the mist) and Godetia (very pretty shades of pink) will be OK sown direct in the beds from mid to late April, and will self-sow for next year too. Have fun!

Oh, and Clarkia - you rarely see it in gardens now, but that and Godetia are just great. Though I grew them in seed trays first...

You can get great enjoyment sowing your seeds as Bamboo says in trays, I don't know what seeds you have but sow the lot. Easily done in trays, in poly bags if you have to, on the window sill if you have nowhere else. Then prick out all the best ones and plant at you hearts content. The seed packets will give you an idea of height and spacing, but don't be afraid to be adventurous. I used to wait until the clocks went forward before I started anything, because of the extra light , but now I'm fortunate to have 2 greenhouse's. I sow lots, especially annuals, have a look at my blogs if you want. Good luck, if you need any help, don't be afraid to ask, there's always someone on here to help.

Bamboo..... The first ever plants I grew from seed, free from a packet of Kellogs :o))

Pretty things, aren't they, Littlelegs - I also particularly like Californian poppies, which pop up by themselves in subsequent years.

Nothings impossible Tilly,but it sounds challenging.just think how lovely it will look.Maybe you could mark out some blocks with sticks or stones,in at least the fronts of your borders,and sow some of the same variety in each block,maybe the smaller ones,label them,and see if they germinate?.You sound as though you will have lots of seed trays otherwise.....You could still sow some of the same in your trays,and plant in the gaps if some fail? ..Just a thought,but good luck:o)

You can always endear yourself to neighbours by offering them your excess. Failing that I'm sure a school or church fete or even a charity shop would be glad to have them.

Thanks everyone. I've spent the weekend selecting which seeds i'm going to sow this year and trying to work out qty's. There simply isnt the space to sow full seed packets so this year is definately a trial and error year. I'll keep a record of the numbers i sow, and what eventually end up in the ground so i can adjust accordingly next year. I have all my seed trays and 2 shelving units in the conservatory which will take two thirds of these, with the remainder going on windowsills. Am a bit dubious of sowing straight into the ground as i tried that last year and the dear little slugs got most of them, so want to wait until they are a good size before they are planted out after the frosts. At least it'll keep me quiet for a while........................;0)