Some expert advice on a struggling azalea
Glad you found it
tbh I don't know if raised beds would work long-term. It's not something I have any experience of.
Why not post another question asking that question.
There are many forum members who garden on alkaline soil, they may be able to offer some guidance.
Hope you can work something out for your fave plants
Knowledge is knowing that a tomato is a fruit.
Wisdom is not putting it in a fruit salad.
You can't change your soil type, especially when it's as strongly alkaline as yours, but you can grow plants in pots with ericaceous soil. You are limited by the size of pot you are able to handle, but you might be able to concoct an 'acid' landscape with a collection of pots, or in a raised bed by burying or part burying pots. A few strategically placed rocks might aid the effect.
Acers will grow well in pots into well sized trees, if the pot is large enough and it gets the water it needs. They need a position in shade/part shade with shelter from wind and very hot sun which both cause leaf browning. The smaller Japanese azaleas would work well and are evergreen for winter interest and you might just manage one of the scented deciduous ones by careful choice and judicious pruning. Pines are sadly not going to be the giants you love, but varieties of Pinus mugo are small enough to grow in pots and full of character. They grow very slowly but do eventually get larger. I had one on my rockery that outgrew its generous space after 30 years and am now on my second which is growing more slowly in a slightly less favourable position.
You might consider adding camellias to your 'acid' garden too.
We brought rhododendroms,azaleas with us, 30 years old and moved 3 times. Hubby made a raised bed in shade under a eucalptus bought a couple of ton of ericaseous soil, not compost. We are on clay with a fairly neutral soil, inherited rhodedendrons, have both camelias and acers growing happily in the ground.
west central Scotland
Neutral soil is fine for the Azalea family, Camellias and Acers, generally speaking, but it's better if it's nearer the acid side of neutral, not alkaline.
It's certainly a better idea to construct raised beds for your plants, which can then be filled with a more suitable growing medium. What you make them with is down to your preference and budget. If you love that type of plant, it's worth considering building a site for them, otherwise, they'll always struggle.
Having said that, there are considerations - they'll need to be a really decent size to accommodate those shrubs/trees, so that you get the best from them. You'll therefore need a very large amount of soil to fill them, and it does need to be soil, not compost.
You can then add to that each year on a regular basis to keep it all healthy - just as you would with soil in a border. Organic matter- bark, leaf mould, and home made compost are ideal.
Beds will also need lining at the base, with drainage holes, so that the contents don't mix with your alkaline soil too readily, although a trench/bed of gravel, or similar, below ground level would also help with that, rather than being directly on the soil. That eventual mixing would take a long time though, so as long as there was a good amount of organic matter added to the beds on a regular basis, and mulching to help with moisture retention [bark is excellent for that] you should get many years from the contents.
It's a place where beautiful isn't enough of a word....