I don't know what a 'Longwood tree' is, and neither does Google - however, you've said red, and at the bottom, the site says on plant Cornus alba, so I'll assume that's what you've got, though you don't say which variety you have.

There are several varieties of Cornus alba, some of which (Elegantissima, for instance) get large if left unpruned. All sucker to an extent, and they aren't particularly fussy about soil - will tolerate both full sun and a fair bit of shade, though not total shade. If you want bright red stems in winter when the leaves have dropped, you must remove at least half the stems down to ground level each spring - the new growth each year has the reddest stems.