In all the excitement of Gold Medals and celebrities, it's worth asking the question: "Why do it?" Rather like one of Mary Berry's multilayered cakes, Chelsea offers different flavours as you cut through it.
Chelsea's traditional role is for plantsmen and women. Exhibits demonstrate the highest quality of plant husbandry applied to old favourites and novel upstarts. Judging by the ever widening avenues in the main marquee, finding competent exhibitors is becoming more difficult.
The emphasis is shifting towards designing gardens both great and small. Companies and charities apparently see significant returns on this investment. Few other events get 12 hours of television coverage supported by celebrity names and the Monday evening party, it seems, offers opportunities for informal financial and commercial discussions. Main board members quietly test out prospective deals in seclusion.
During Chelsea week, hobby gardeners in their thousands are attracted by horticultural splendour at its best. Hopefully, from this also comes relaxation and renewal. Enjoying plants and being with plants are palliatives for stress and anxiety.
Horticulture is also a powerful force for sustainable environments and enhancing biodiversity. Crucially, these help mitigate adverse climate changes. Chelsea's role highlighting horticulture's environmental and social benefits is gaining momentum.
Business sustainability is also essential. Companies attracted by trading opportunities at Chelsea are another magnet for hobby gardeners. This show holds trading in check partly by tradition and partly by the size of the site. Nonetheless, visitors want to buy and that urge should be satisfied.
There are also business achievements beyond the Royal Hospital's gates. Chelsea is now a worldwide brand bringing trade into and out of London across the globe. These many layers make very good eating.
Professor Geoffrey Dixon is managing director of GreenGene international