Basic questions!

[JumpJockey]

A few pretty basic questions, we're still new to the whole gardening thing...

Last year we did pretty well with tomato grobags, but haven't got round to moving the now empty-of-plants bags. Is there anything we can do with the soil? We don't have any beds as such, just grass with brambles/hedge which form the borders with neighbours so not really anywhere to put the soil. Would it be any good in pots, or is it all "exhausted"?

Dd and I planted some bulbs in pots which are starting to sprout Once the flowers are done, is it safe to plant other things on top, or should we have done this before they started to grow?

And finally a very basic question. There's a "patio" bit which used to be a shed base, that has gravelly rubbish around it and we'd like to dig the weeds out and plant lavender, big rosemary plants etc to make a sort of sitting area. Is this practical - as in, are there likely to be weed roots going down miles that will grow back, or should it be possible to go over with a fork? And do we mix the gravel back in, or hoick it all out and put somewhere else, and then fill the space left behind with topsoil? Or even use the old tomato grobag soil?!

Thanks very much for any suggestions - we're not even at the choosing plants stage yet, just trying to get things ready!

[bumperella]

Tomato grow-bag compost will be lacking nutrients (as in, will be used up) and the structure is likely to've been spoinlt. However I tend to spread mine on flower beds despite all that. I would use it around the patio area as lavendar etc doesn't like rish soil anyway.
Spring bulbs tend to be pretty knackered after having grown in pots for a year. So I'd wait until they've flowered, then tip the lot out and plant them somewhere else in the garden.
Get fresh compost for the next lot of plants: summer bedding is generally "hungry" and usually the compost will have run out of nutrients after about 6 wks. If you re-use the compost yr summer bedding may well fizzle out early (also, feed your summer bedding - slow release granules mixed into the compost is easiest).
Re: weed roots et - impossible to say without knowing what the weeds are. I'd be tempted to dig out the gravel and weeds. Dig the tomato compost in. Then add topsoil (sounds like you'll need it?). Wait and see what weeds the appear. If they're nasties (eg groundelder, bindweed) then use weedkiller to get rid (gypsophylate, so something like Roundup (which will kill the plant you spray it on), and NOT and not Pathclear which is for driveways etc and will kill anything you plant afterwards).

[JumpJockey]

Thanks so much! I did some good digging of the bit by the shed-base patio and actually once I'd lifted the gravel and the weed control cloth (ha!) the soil below was pretty good - quite compacted, but it turned over nicely and is full of worms which I'm taking as a good sign :) Will mix in the gro-bag compost as well.

There is definitely ground elder in places, in the garden but I didn't see much in this area, so fingers crossed it won't be too bad. Mainly there's bramble roots, which dug out quite easily, and bits of ivy, which again was very satisfying to remove :) I'm feeling optimistic that it will be good for lavender and herbs.