I gotta ask...who really cares what the side facing a permanent barrier such as a block wall looks like? Of course it's gonna look sh%##y, but unless you plan on a second life as a fairy or a toad, you aren't going to be spending a lot of time looking at it...which is why you planted something in the first place, to hide that barrier and to have the much more aesthetically pleasing plant facing you, not the wall, look good. And as for width, there are solutions for that. As far as the effect of spacing on root growth, not sure anyone has the answer to that, not sure it has been studied in that way. Every spacing study i've seen is about top development, and most discussions i've had are about practical matters, such as how wide to allow for ease of digging with (brand) spade. Strictly speculating, i'd say that similar to development of crowns, closer spacing may push roots to grow where there is less competition, pushing wide out from the row, but roots also freely form grafts where ever they cross, so it may all be blowing smoke to even try to answer the question.

Aloha Maiolo, I have stephanotis vine that is covering my chainlink fence and it is still blooming. I live on Oahu, in Kaaawa. I feed it with Miracle-grow sporatically. I just spray it on with a spray bottle. Seems to really give it a boost. There is a vining ylang ylang also. Artabotrys hexapetalus - Ylang-Ylang Vine

Podocarpus macrophyllus var. maki Siebold & Zucc., Abh. Math.-Phys. Cl. Königl. Bayer. Akad. Wiss. 4(3): 232 (1846).This name is accepted.Distribution:S. China to N. Myanmar, Taiwan, SC. & S. Japan 36 CHC CHS 38 JAP TAI 41 MYA (81) lee pueLifeform:Phan.Family:PodocarpaceaeOriginal Compiler: R.Govaerts Homotypic Synonyms: Podocarpus maki (Siebold & Zucc.) Pickering, Chron. Hist. Pl.: 631 (1879), nom. inval. Podocarpus macrophyllus subsp. maki (Siebold & Zucc.) Pilg. in H.G.A.Engler (ed.), Pflanzenr., IV, 5: 80 (1903). Nageia macrophylla var. maki (Siebold & Zucc.) Voss, Mitt. Deutsch. Dendrol. Ges. 16: 90 (1907). Margbensonia maki (Siebold & Zucc.) A.V.Bobrov & Melikyan, Byull. Moskovsk. Obshch. Isp. Prir., Otd. Biol., n.s., 103(1): 60 (1998).Heterotypic Synonyms: Taxus chinensis Roxb., Hort. Bengal.: 73 (1814), nom. nud. Juniperus chinensis Roxb., Fl. Ind. ed. 1832, 3: 840 (1832), nom. illeg. Podocarpus chinensis Wall. ex Benn., Pl. Jav. Rar. 1: 39 (1838). Podocarpus makoyi Blume, Rumphia 3: 215 (1847 publ. 1849). Podocarpus japonicus Siebold ex Endl., Syn. Conif.: 217 (1847). Podocarpus lanceolata Gordon, Pinetum: 275 (1858), nom. inval. Podocarpus corrugatus Gordon, Pinetum, Suppl.: 88 (1862). Podocarpus flagelliformis Carrière, Traité Gén. Conif., ed. 2: 666 (1867). Podocarpus miquelia Parl. in A.P.de Candolle, Prodr. 16(2): 516 (1868), nom. inval. Podocarpus macrophyllus var. chinensis (Wall. ex Benn.) Maxim., Mélanges Biol. Bull. Phys.-Math. Acad. Imp. Sci. Saint-Pétersbourg 7: 562 (1870). Podocarpus appressus Maxim., Bull. Acad. Imp. Sci. Saint-Pétersbourg, sér. 3, 15: 379 (1871). Podocarpus chinensis var. argenteus Gordon, Pinetum, ed. 2(Suppl.): 88 (1875). Podocarpus chinensis var. aureus Gordon, Pinetum, ed. 2(Suppl.): 88 (1875). Nageia appressa (Maxim.) Kuntze, Revis. Gen. Pl. 2: 800 (1891). Nageia chinensis (Wall. ex Benn.) Kuntze, Revis. Gen. Pl. 2: 800 (1891). Nageia corrugata (Gordon) Kuntze, Revis. Gen. Pl. 2: 800 (1891). Nageia flagelliformis (Carrière) Kuntze, Revis. Gen. Pl. 2: 800 (1891). Nageia japonica (Siebold ex Endl.) Kuntze, Revis. Gen. Pl. 2: 800 (1891), nom. illeg. Podocarpus chinensis var. appressus (Maxim.) Matsum., Shokubutsu Mai-i: 223 (1895). Podocarpus macrophyllus var. appressus (Maxim.) Matsum., Index Pl. Jap. 2(1): 16 (1905). Podocarpus chinensis var. wardii de Laub. & Silba, Phytologia 65: 331 (1988). Margbensonia chinensis (Wall. ex Benn.) A.V.Bobrov & Melikyan, Byull. Moskovsk. Obshch. Isp. Prir., Otd. Biol., n.s., 103(1): 59 (1998). Podocarpus chinensis subsp. wardii (de Laub. & Silba) Silba, J. Int. Conifer Preserv. Soc. 17: 9 (2010).

What killed the oak? Do you know? It matters because it can have an effect on how your replacement plantings fare. The main thing about plantings around filtered swimming pools is that nothing be chosen that generates small parts liable to be sucked into filter intakes.