The variety of Acer is important, they all differ in height and spread. If you've just bought it, it should say on the label what the spread will be.

Hydrangeas vary a bit, but the usual mophead or lacecap varieties will, over time, get up to 8 feet wide. Rosemary eventually makes 6 feet wide, over some years, but its usual for people to restrict it by pruning back in May. I'll leave you to work out the math!

Hi bamboo. Thankyou for you reply. Could I also ask if it is possible to keep the hydrangea prunes to a size of my liking?

Not really, unless its Hydrangea paniculata, which can be cut to the ground in autumn and will grow again. Hydrangea macrophylla varieties (mopheads and lacecaps) should not be pruned until new growth begins in spring, and then only pruned to take off the previous year's flowers and any dead bits. The only other option with those is to take out selected shoots or stems, up to half, spread throughout the bush, when the plant will produce longer shoots with, obviously, fewer, tho larger, flowers.

I notice I say up to 8 feet wide - some may only get 6 feet wide, but one of my customers had an old one in her front garden and it was 10 feet across when in full bloom.

Also, you may want to rethink your planting. Rosemary likes full sun, whereas Acers prefer dappled shade or part shade. Their soil requirements are also quite different.

Just a thought - when you are sure what size you want a plant to grow to always check the plant label to see how big it will get. Keeping a large plant small by pruning seldom works well. It is so easy to be seduced by an attractive little shrub in the garden centre without realising it will grow to six feet tall... If the plant you like will grow to be too big its best to avoid it anyway choose one that will stay small on its own.

Thank you all. I'll move the rosemary to a sunnier spot. I haven't been here long so I'm still learning where gets shade throughout the day. I'm struggling to be able to upload pictures due to my phone I think. Has for soil types. How would I go about having different soils around the garden or could I plant in large pots and plant the pot in a different type of soil? I'm future questions I will try and include the variety of species to give a better idea of what I have.

Regarding soil types, you'll know already if its heavy and clay, or light, stony/sandy, just from digging it and seeing how quickly or not it dries out. Japanese Acer varieties don't like lime in the soil - they're happy in a neutral to acid ph, and that you can't really tell from what the soil appears to be like in terms of heaviness. But hydrangeas are a good litmus paper - if you plant a blue hydrangea on alkaline (limy) soil, the flowers won't be blue, they'll either be pink (if the soil is very alkaline) or lilacy pink if the soil is neutral, they're only blue in acid conditions. This only applies to the mophead blue or pink varieties - pinks turn blue on really acid soil.

Otherwise, have a look around the neighbourhood - do you see rhododendrons growing healthily in the ground, or Pieris varieties or Skimmias, and other Japanese Acers come to that. If they're all growing well in the soil, then you've likely got neutral to acidic soil conditions.

Regarding sun and dryness of soil, unless you're very unlucky or the garden's tiny, every garden has drier, sunnier spots and shadier, damper spots - it's just working out where they are. So putting your rosemary in a sunny drier spot, and the Acer in a shadier, damper spot is the way to go. If your Acer isn't a Japanese one (Acer palmatum varieties) then soil ph doesn't matter.

Digging over and adding humus rich materials like composted animal manure prior to planting is key - or alternatively, after weeding, spreading composted animal manure over the soil when its damp. Adding that type of stuff to the soil improves growing conditions, enables plants to grow better, and helps retain moisture.

Lastly, yes you can of course grow things in pots, but its not a good idea to sink potted plants into soil for any length of time - they always go through the hole at the bottom and root into the surrounding soil anyway.