Yeah, we’ve all got ’em: those packets of seeds we got ages ago and meant to sow but somehow they got stuck at the back of a drawer and, well, the sow-by date is 2016 but…

I’m very much of the ‘stick it in the ground and see if it will go’ school of thought but at this time of year, however empty the allotment beds may look, somehow they’ve all been reserved. There just isn’t the room to experiment with seeds that may or may not come up. And there’s a veritable queue for the propagator.

Here’s a handy little test for seeds – if it works, it’s worth gambling some space in the propagator for the rest of the packet.

You’ll need:

• A packet of dodgy-looking seeds
• A dinner plate
• A couple of sheets of kitchen roll
• clingfilm
• A plant mister (though there’s ways round it if you don’t have one.

Put a couple of sheets of kitchen roll on the plate, then moisten under the tap. Make sure it’s nice and wet.

Put a pinch of the seeds onto the tissue. You don’t want to use many – work it out depending on how many are in the packet – if there are hundreds of seeds use more. If there are only about ten, don’t waste nine of them. It makes sense – if a plant produces thousands of seeds, it usually expects most of them to be duds or get lost anyway, so use a bigger sample. If the seeds are large in the first place it may be worth soaking them overnight first anyway.

Mist the seeds with the plant mister and loosely cover with the clingfilm. Keep the plate indoors, somewhere where you will see it a lot to be reminded to keep it damp. Every so often lift the clingfilm and give it a quick mist.

If you’re using the plate for more than one type of seed, make sure you have some way of knowing which is which. Labelling is best, though in this instance, where I had four suspicious varieties of carrot, I just arranged the packets in a wheel.

Viable seeds should start to sprout in a few days (check the packet for seeds that take a long while to germinate). If they work go ahead and sow.

Two more things:

1 If the sow-by date was quite a long while ago, I’d sow a little more thickly than usual then thin out any extras.

2 Never bother using this method with parsnips. Parsnip seed only ever works fresh. It will not come up with any kind of reliability if it’s over a year old.