The Shoebox Sow-Off: Giving Your Leftover Seed Packets a Second Life

Every garden shed in the country has one. A biscuit tin, a shoebox, a carrier bag knotted at the handles, packed with seed packets that seemed so sensible at the time. Some are three years old. Some have gone soft at the corner. One is from a magazine freebie in a year you would rather not admit to.

November is the right month to deal with it. The beds are mostly done, the catalogues are landing on the doormat, and there is still enough dark evening ahead of you to be honest about what you will actually sow.

Tip it all out on the kitchen table

No sorting in the shed. Bring the whole lot indoors, put the kettle on, and make three piles: sow next year, test first, and compost.

Ignore the date you bought it. Look for the sow-by date on the back, then think about what kind of seed it is, because keeping quality varies wildly between crops:

• Beans, peas, sweetcorn, brassicas, cucurbits: usually good for three to four years in decent conditions.
• Tomatoes, peppers, aubergines: surprisingly durable, often four to five years, and worth testing before you bin them.
• Parsnips, carrots, onions, leeks: the opposite. Parsnip seed is famously short-lived; treat last year's packet as suspect and this year's as gold.
• Anything damp, mouldy or stuck together: compost. No heroics.

The kitchen roll test

This is the cheapest useful thing you can do all winter. You need ten seeds, a sheet of kitchen paper, a plastic bag or a takeaway tub, and somewhere warm — an airing cupboard or a shelf above a radiator at around 18–20C.

Write the variety and the date on the bag. Dampen the paper, space the seeds out, fold or cover, and check every couple of days from day seven. Parsnips and parsley will dawdle; brassicas and radishes will be up in days.

How to read the result:

• Eight or more out of ten: sow as normal.
• Five to seven: sow at double density and thin hard later.
• Four or fewer: bin it and buy fresh. You will spend more on compost and disappointment than on a new packet.

Do not test everything. Be selective — test the expensive F1 tomatoes, the heritage beans from the seed swap, anything your plan depends on. Testing a 90p packet of radish is a hobby, not a strategy.

Damp is the real enemy

British winters do not freeze seed, they soften it. A shed that swings between condensation and cold, or a garage with a leaky corner, will finish off a packet faster than three summers in a dry drawer.

What works:

• A screw-top jar or a proper tin with a couple of silica sachets nicked from new shoes.
• A cool, dark, steady spot. Under the stairs beats the greenhouse every time.
• The fridge, if space allows, as long as the container is genuinely airtight.
• Labels. Write the year on the packet in pencil so next November you are not guessing.

And keep peas, beans and sweetcorn in metal. Mice can chew through plastic bags and cardboard with depressing ease.

Be realistic about bed space

Here is the uncomfortable part. Seed is cheap; growing space is not. A single tomato packet holds enough seed for several years of planting, and a £3 packet of courgette seed could fill a small allotment.

Before you order anything, draw the plot. Count the beds, note what is staying put — the rhubarb, the fruit bushes, the perennial herbs — and work out roughly how many plants of each thing you can actually fit at the recommended spacing. Then halve the number of varieties you were planning.

A useful rule: choose two reliable varieties per crop family rather than six experimental ones. You will eat better and swear less.

Plan backwards from the plate

Rather than starting with the catalogue, start with what you cooked last month. If squash soup and roast roots filled your November, grow more of those. If the chard went to seed before you got round to picking it, grow less chard.

A realistic 2027 plan for a small garden or half plot might look like: two tomato varieties (one salad, one cooking), one climbing bean, one dwarf bean, a row of beetroot, perpetual spinach, one courgette plant, a squash, garlic and overwintering onions, plus a few cut-and-come-again leaves. That is a full, generous year and it costs very little when half the seed is already in the tin.

Where to top up for free

Before you buy, look sideways. Allotment societies run seed swaps from January, and many towns hold Seedy Sunday events in late winter where growers bring along their spare packets. The Heritage Seed Library is worth joining if you like old varieties and want to help keep them going. A neighbour with a bigger plot will almost certainly have half a packet of something you need.

The November job list

Sort the tin, bin the mush, test the doubtful, jar the rest with a silica sachet and a label, then draw the beds on the back of an envelope. One rainy afternoon now saves a lot of muddled sowing in April — and it means the money you do spend on seed in 2027 goes on the varieties you genuinely want to eat.