My garden is large, but is on a steep slope. It's grass covered and has been landscaped so there's a nice flat area with a tree halfway up. The slope makes it difficult to properly mow and maintain the grass on the slopes.
The soil is generally poor - very high in clay. Right at the top of the garden is an area with a lot of stones which we couldn't landscape or lay turf on.
This area has always been a magnet for weeds. One of the houses next door is rented and the tenants (while otherwise pleasant) don't care for the garden at all and it's a mess of brambles, dandelions and other weeds. Of course, all the weeds growing in these areas spread into my lawn.
Furthermore when we had the garden landscaped the gardeners must have broken up bindweed roots in the soil so the lawn is now full of innumerable small bindweed plants. As if that wasn't enough, the poor drainage of the soil encourages a lot of moss growth during the winter.
The end result of all these factors is that a few years after we had the garden landscaped, and despite our best efforts, the garden is now absolutely full of weeds. There are more varieties than I can count including nasty plants like thistles and briars. There's also quite a lot of wild grass.
I have tried spraying with grass-friendly weedkiller, pulling off seedheads when I find them and doing my best to cut leaves and get roots where possible. But it's a losing battle: it gets worse every spring. This year I think I have more weed than lawn.
Is there anything I can do to save this situation, or am I just going to have to put up with having a semi-wild garden?
EDIT:
Our landscapers were, I suspect, quite inexperienced. They seemed far more interested in the artistry of landscaping than the practical requirements. Although they did a decent enough job with the budget and our requirements, they chose bad ground cover plants for bedded areas and didn't plan well. I suspect they just never considered the possible maintenance overhead of the banks. We have considered ripping them up in favour of artificial grass.
It is possible to get a mower up and down the banks but it's extremely hard work and feels very dangerous. I know mowers have auto-cutouts, but you'd only have to stumble once and you could still have a nasty accident. When you do mow, the slopes and lips up to flat areas makes it difficult not to scalp the grass and actually make growing conditions for weeds better.
There is no barrier at all between us and the weedy garden next door. The steepness of the slope overall makes fencing a difficult and expensive option. So seeds blow over constantly, and spreading plants like briars just grow under the earth and pop up.
I will try and post some photos later.