My Gran used to have a forsythia bush which grew in an old tin bath in her back yard in central Bristol. It was a tiny, dark, overshadowed back yard, but every year around March the forsythia would light the place up. When Gran moved in with us (that's Mum, Dad, Sis, Bro, me & dog) the forsythia bush came with her & was planted in a corner of the garden. Being a largish bush it took to its newfound freedom and thrived, lighting up what was otherwise a light, airy (gale-blasted at times) & quite reasonably sized new back garden on solid clay sub-soil.
Thirty years on it's still lighting up the Spring, holding up the fence, providing nesting places for local birds & requiring a severe 'haircut' each April/May after flowering.
Do not knock the humble Forsythia bush, James. There may be many more delicate, rarer & more up-market shrubs for spring. How many of them would cheerfully blossom every year in a tiny back yard, then continue for another thirty-plus years in solid clay?