Suitable plants

hostas not 'hosts' , sorry!

A bit late to the party, but my suggestions would be:
In the long thin border plant campanula carpatica and/or pulmonaria blue ensign - both tough plants, evergreen,blue flowers and loved by bees.
Your square bed I would suggest covering with gravel and have pots that can be changed with the seasons - hosts would be great, eunonymous would be evergreen, perhaps a maple if the area is sheltered? And if you feel up yo it you could have pots of annual seeds such as cornflower and cosmos, or bulbs in the spring. Good luck!

In that very narrow strip, why not plant lavenders? They provide a nice low border if you keep them trimmed. Or heathers. I have just planted a heather bed at the side of my drive. I’ve planted a dozen and they will soon fill out. I have a few heucheras and find that the red shades fare better than the green/yellow varieties in sunlight, but they are glorious plants and such a huge variety. As others have said, thyme may fit the bill in the narrow strip. It’s evergreen and soon fills a space. The photo is what started out as a small plant on my rockery wall, but has now got its feet under the table!

Correction - along the slabbed path have someone get rid of the weeds completely in a strip a few inches wide, and plant creeping thyme along the edge instead. The mower wire can stay as it is, and the mower will cut up to the thyme. The rest of the thyme will not grow very high and will make an edging to the grass. It will gradually spill over onto the edge of the path, where it can be walked on, or trimmed back if it starts to get a bit much.

The first paragraph was about the extra patch of decorative slabs.

I would get those decorative stones removed and replaced by slabs. If you can't see them for the weeds, they aren't very decorative, are they? It is quite a small job and won't cost much. The robot mower wire will be OK where it is, if it is buried. If it is above ground, contct the makers for advice.

In the other strip I would plant creeping thyme on it, with flowering plants nearer the back (the creeping thyme is about 3 inches high and has pinky-purple flowers on it, and smells of thyme, and can be walked on to attend to the other flowers. )

I know nothing about robot mowers but I would remove the decorative stones as Elegran suggested.
Could you have matching paving stones put down on the other area?

You're getting technical now!! 😁

(Sorry, no I don't.)

Yes - I thought of just ditching the stones and having the grass go right up to the slabs - but this involves resetting the mower guidewire and I am not sure how feasible this is. Does anyone know?

Could you lose those and make that strip either earth, slabs or grass? That would remove one bit of work.

It is not the slabs that are tge problem with the mower but the little decorative stones in the strip by the slabs.

Even the weeds looked better after they were cut!

Are you sure that it can't overlap the slabs? My robot mower could run over the slabs as long as they were no higher than the ground under the grass. The blade could be set to various heights, but they would all cut at maybe an inch or so up the grass stems. (I am not sure exactly the minimum height, but it was obviously higher than ground level.) It made a very neat edge where the grass met the path, and saved quite a bit of work.

Success!!!!

https://www.gransnet.com/uploads/talk/202507/medium-fpanui-patch.jpg https://www.gransnet.com/uploads/talk/202507/medium-1clj72-path.jpg

Another attempt top add the pics ...

The narrow strip along the path by the lawn already has a membrane and stones. At the moment it is mostly full of weeds. One challenge is that I have a robot mower and this cannot mow right to the edge ... there is inevitably a small strip where the grass grows up because the mower wire needs to be far enough back to stop the mower going over the stones.
So whatever I do with the stony strip I will still need that strip of higher grass to be trimmed. I guess I might possibly manage a very lightweight striker.
If only I could get people to work on tge garden for me ... but thy want big lucrative jobs; not my little garden.

Lots of ideas for me! Thank you

Alpine like gravel areas.

Luckygirl3

I have a large gravel area at the front of the house. I park my car on one half and the rest is full of lots of tubs with assorted plants in. They need lots of watering!

Plants that are put in through holes cut in the membrane won’t take anything like as much watering as plants in pots.
An alternative method is to dispense with the membrane and just mulch with gravel.

This will work well if you have help with removing any weeds that get through.

Luckygirl3

How would I water the new plants in if there us a membrane?

Buy a permeable landscape fabric. It lets water through but suppresses weeds and once the plants have ‘got away’ you can then mulch with gravel, covering the whole area, taking care not to damage the new plants. They’ll be fine once established. Keep up the watering in the early days as it will easily penetrate the gravel.

This is a good time of the year to do it as the plants will be established by autumn/winter when you can stop watering

I have a large gravel area at the front of the house. I park my car on one half and the rest is full of lots of tubs with assorted plants in. They need lots of watering!

Luckygirl3

Would the evergreen geranium work in that way merlot? Or creeping thyme?

Yes. They are dead headed or cut back after flowering and then behave like any other perennial giving a new flush of leaves. Evergreen ornamental grasses are also good for winter interest. Go for drought tolerant plants that need very little water once established.

How would I water the new plants in if there us a membrane?

Would the evergreen geranium work in that way merlot? Or creeping thyme?

That’s why I suggested a gravel border, Luckygirl.

If your garden helper digs out the grass, composts and levels it, you can lay some black landscape fabric on top to suppress any weeds and grass. You then make a rough plan of how you want it to look and cut out some planting holes ready for your new plants. When you have planted and watered them you mulch/cover the whole area with a generous layer of gravel. The plants will be able to grow and thrive without weed competition so long as they are well watered until they are established. You can place pots on any part of it you think looks a bit bare and they can be moved around or removed as the border takes shape. You can also scatter seeds like poppies and Nigella because they thrive in gravel.
How you edge it is up to you and how it sits in relation to other established plants.

Have a look on YouTube, Beth Chatto’s gravel garden for inspiration.