I’ve just found a box full of zinnia seed packets that I bought several years ago to give away to promote The Laundry’s zinnia bedlinen. I have kept the box in the bottom of the fridge for most of that time. I love these flowers as they grow in such great colour combinations from brassy yellow to burnt orange to mucky pink.

I haven’t had a great success growing zinnias myself though each year I get that bit better at it and am hoping to crack it this year. The trouble is that slugs absolutely love the seedlings so you need to either be very lucky, or more likely use a combination of vigilance and cunning to outwit them. Last years attempt did result in a handful of lovely blooms but the leaves below them weren’t anything to be proud of and to reach that stage I had started the seeds off in pots, planted them out, each one in a plastic tube made from a recycled water bottle edged with copper tape, positioned them close to slug traps that needed to be replenished with beer at regular intervals and sprinkled organic slug-away, slug-off or whatever the acceptable eco friendly slug pellets are called, on the soil surrounding them. Granted it was a very wet summer, so that didn’t help, but surely it’s not meant to be quite that difficult.

Now seven months on, the agony seems to be but a distant memory and this year I am again visualising vases of zinnias filling my house by late summer ’08 and a zinnia supply so plentiful I’ll be giving bunches away to my neighbours as well.

First things first though. Are these seeds even worth bothering with? Not knowing whether the seeds would still be viable after 5 or more years I thought it best to do a viability test to decide whether chucking them on the compost heap would be a better option. Luckily zinnia seed, if kept under suitable conditions, can stay viable for 7 or more years.

To test them I took a piece of paper kitchen roll and sprayed it with water so it was somewhere between damp and wet, then placed 20 seeds, evenly spaced out, on the towel. Multiples of 10 make it easy to work out the viability percentage but obviously if you don’t have many seeds to begin with use fewer.

The kitchen roll was then carefully rolled up, the roll placed in a sealed polythene bag, the bag placed in a warm airing cupboard, in the dark. That was on Saturday. Today, 3 days later, I thought I’d have a look see how they were doing, and lo and behold when I unrolled the towel, all 20 seeds had germinated. This is a really impressive result considering that seeds are supposed to lose significant viability as each year passes. So the seeds are raring to go.