At this time of year, I look through my boxes of seeds wondering whether I stick to the ones I’ve got or whether I should try to buy some new, different ones. My database (well spreadsheet) of tomato seed cultivars is a list of 6,000+ names, most of which its impossible to find a commercial source. Even worse, I think its increasingly common for websites to say “unfortunately we don’t ship outside the country”, so many “obscure” cultivars aren’t available.
When you look at the big suppliers, you find they have a relatively limited selection of cultivars and many are F1 hybrids (which themselves are unknown crosses of other cultivars). Personally, I try not to grow F1 Hybrids for two reasons: they’re expensive; if you like them, they’ll go out of availability because maintaining the cultivar is difficult.
Now I don’t have a problem with them being expensive, creating an F1 is labour intensive and “risky” (I presume that they have to be grown out before you know what you’ve got and they might not be what you expected) but it would be nice if they were available for more than a few years.
Life is getting difficult for the small producers. Increasingly countries (including the UK) require Phytosanitary Certificates before seeds can be imported. Again, I have no problem with this, importing diseases into the UK through infected seeds/plants is not a good idea but the cost of getting a certificate is high and certainly not worthwhile for a few seeds.
Much of my collection has been built up from “seed swaps”. Look around your local gardening clubs and you’ll find like minded people who will happily swap different cultivars with you, promoting a mix of different cultivars which are known to grow in your area.
Alternatively, there are more obscure suppliers in your country who have a wider range of cultivars most of which they have grown themselves. Whatever you do, make sure they are Registered seed suppliers (DEFRA in the UK), otherwise you don’t know where the seeds have come from.