Let the 'Rainbows End' grow like that and see what you get, you even have a good potential leader for the "adult" growth. You've got some space from the Blue Spruce. ...but on such trees would the trunk eventually grow strong enough to support a full size tree? Would not your regular dwarf Alberta spruce be pretty unstable at some point?

Don't plant a Magnolia if you're worried about mess. Someone planted one 50 years ago next to our pool. It is absolutely beautiful and give great shade to the south side of the house, BUT it is very, very messy. The large leaves drop all year, heaviest in the spring, and they take years to decompose. In the summer the beautiful flowers drop bud sheaths and then petals. Later in fall, heavy cones drop and bring tons of squirrels who pull them apart after the seeds and leave a mess everywhere. Plus the cones are kinda spiky, painful if you accidentally step on one, plus a tripping hazard. So yes, a beautiful majestic tree...for the outer edges of a property, not near a patio. You have been warned, lol. The Africarpus gracilior is a pretty good choice, they do get huge with age, but are fast and pretty clean, and handle heat and soil compaction well. Josue Diaz's suggestion of Brachychiton populneus is a good choice too, lovely tree, too tender for where I am, but should do great for you. Stan's suggestion of a Tristaniopsis laurina is a good one too, but pretty slow growing. If you want shade soon, I'd get the largest one you can find. It will be expensive, but save you several years waiting. I love Ficus microcarpa (Indian Laurel)! Beautiful tree, gorgeous white smooth trunk! I just got back from visiting my daughter in San Luis Obispo and the downtown streets are lined with them and they're very majestic. Do be aware that they can get very large buttress roots with age, but if you give them lots of root room near the patio, but not right next to or in the patio, they should be fine.

Update: Eucalyptus deglupta that I raised several dozen of and only this past winter I planted 6 of them into the ground at an elevation of around 150 m above sea level, into a poor "soil". They did not grow too large in their pots over the past 5 years. After clearing an acre or so of shrubby woods with an excavator I was struggling to find some soil to purchase in order to cover the field. The soil I covered it with by just a barely a foot or so is very poor and has a lot of volcanic "gravel" in it mostly, stones and clay. It is dug up from down deep so it has got no organic matter yet. Finally the 6 x "Arcoiris" (Rainbow Eucalyptus) are in the ground and are slowly growing. Some showing deep, red foliage and some green foliage. The bark is still mostly light brown with some opened up patches of light green. They should show more colour when the trunks grow to at least 10-15 cm thickness if they will have tropicals colours here at all. Will see how their bark will look after several more years, whether all brownish and light green or will show some more tropical colours such as orange, red and especially blue. I will post an update then and now here are some photos of the pot-grown ones after 5 years (they grow very slowly in the pots): Anyone growing these in Portugal or Spain please post up close photos of the bark of larger E.d. (Eucalypto arcoiris) trees if possible.

Wish someone would produce Camper down hybrid resistant to Dutch Elm disease. I suggest visiting forests, to shop for one of a kind species variety. When researching identification of few large individual urban trees, each revealing unique traits they had in common. I discovered that during 1800's, horticulturists took daily excursions into wild forest searching out new unique specimens. Then categorized, documented and sent sample for official designation of their find. And sold off collected cuttings to distant communities where early residents planted several across town. As a local tree historian rediscovering these unique varieties propagated so long ago. I secure organisms continued existence, by rooting or grafting vegetative and hardwood cuttings from parent tree. Even back then, cuttings primarily selected for beauty. Unless collected from large old mature trees, which already proved to have good branch attachment and structure. Today last of these unique trees originally propagated from wild varieties, and planted by early community members. Have proved over last century that their uniquely evolved qualities make them great candidates for urban plantings. I thought this was how Morton arboretum re-discovered Fremanii variety, a natural hybrid between Silver and Red maple which commonly mix in wild. Since parent tree was selected from the collections at The Morton Arboretum, and assumed that specimen was wild variety discovered and replanted long ago. Oliver Freeman first grew freemani at U. S. National Arboretum in 1933. And AUTUMN BLAZE, is an older cultivar that was discovered by nurseryman Glenn Jeffers in the late 1960s. And since then, over last century Arboretum tree proved to have good attachments and dominant leader. But learned that was not the case. And normally scientists do not search grounds to rediscover one of a kind old survivors that can become new urban tree selections. When speaking with someone from staff at arboretum involved in Freeman cultivation project. I kindly reminded them how past horticulturists had also been selecting Varieties of Silver Maple for good attachments long ago. Just like Morton promotes with their Marmo Maple cultivar today, stating selection has a strong central leader and excellent branching habit