ColdharbourSeed

Seed you can
sow again

Eleven acres near Coldharbour, growing 140 open-pollinated varieties for seed. Everything here is grown out on site so we know it comes true, hand-harvested, hand-cleaned, and packed in paper. Nothing hybrid. Nothing treated. Nothing bought in from a wholesaler and relabelled with our name on it.

Open the plan Why that matters
Varieties
140
Grown out
11 acres
Hybrid seed
None
Plan of the eleven acres at Coldharbour A site plan showing the four rotation beds numbered one to four, the herb strip by the packing shed, eight flower rows, twenty-two grow-out rows kept apart for trueness to type, a polytunnel, the seed shed and drying loft, the pond, and the hedge along the north boundary. A north arrow points up and a scale bar shows fifty metres. HEDGE, NORTH BOUNDARY 1 Brassicas LIMED, NETTED 2 Legumes HAZEL SUPPORTS 3 Roots, onions NO FRESH MUCK 4 Fruiting, leafy HEAVY FEED Grow-out rows 22 ROWS · ISOLATED FOR TRUENESS Flower rows CUT AND SEED Herbs BY THE DOOR Seed shed DRYING LOFT OVER Polytunnel POND N 50 m
Coldharbour, drawn spring 2026. The four beds move on one place each year.

What to sow now

Pulled from the sowing windows on the packets, not from a marketing calendar. If a variety is not listed this month, it is because sowing it now would waste the seed.

All 25 in the catalogue

    Four beds, and everything moves on

    The catalogue is arranged the way the ground is. Each variety belongs to a rotation group, and the shop plan flags which. This is the rotation itself: read down a column to see what that bed grows, year after year.

    The four year rotation. Each group moves on one bed a year and comes back to where it started in year five.

    Hybrid seed is a rental agreement

    An F1 hybrid is two inbred parent lines crossed under controlled conditions. The first generation is uniform and vigorous, which is genuinely useful if you are a commercial grower harvesting a field in one pass. Save its seed and the second generation falls apart into its grandparents. You cannot keep it. You have to come back next January.

    Open-pollinated seed comes true. Save it, sow it, and you get the same plant, and after a few seasons of selecting from your own best plants you get something slightly better suited to your soil than anything a catalogue can sell you. That is how every variety in this catalogue came to exist in the first place.

    Six companies now control most of the varieties on a garden centre rack, and the ones that get dropped are the ones that do not ship well or ripen all at once. Crimson Flowered broad bean was down to six plants in the 1970s. It is on page one of this catalogue because a handful of people kept sowing it. That is the entire business model.

    None of which means open-pollinated is always better. Hybrid brassicas hold together in a wet autumn in a way ours will not, and if you need forty identical cabbages on one Saturday you should buy a hybrid. We would rather say that than pretend.

    What is printed on every packet

    01

    The year it was grown

    Not a use-by date. Seed does not expire on a Tuesday. The year tells you how it has been stored and lets you judge it yourself.

    02

    The germination rate from that year

    Tested on 100 seeds on damp blotter in the shed, counted at 14 days. Greek oregano comes in at 78 per cent and we print 78, because that is what the species does.

    03

    How many seeds are actually in it

    Counted, not weighed to an average. A packet that says 180 has 180 or a few more.

    04

    Permission to save it

    In writing, on the back. No variety in this catalogue is protected and none of it is ours to withhold. Save it, swap it, sell it if you like.

    The basket is a plan, so we drew it like one

    Most seed baskets are a list of things you fancied in February. Ours assembles a year while you fill it: chrome for the sowing window, green for when it comes in, and a line marking where you are now.

    It also tells you when you have overcommitted. Four sowings in one month is a Saturday you will not enjoy, and it is much easier to see that now than in April with a tray of seedlings and nowhere to put them.

    Start a plan

    Two of us, a shed, and a very good drying loft

    Coldharbour has been a market garden since the 1890s and a seed holding since 2011. Eleven acres of greensand on a slope, which drains fast, warms early, and means we lose things in a dry July that a clay grower would keep.

    Grow-outs sit in twenty-two rows at the top of the field, well away from everything else, because a brassica will cross with anything brassica-shaped within half a mile if you let it. Anything that throws off-types gets pulled before it flowers and the whole row is logged. It is slow, and it is the only reason we can print a variety name with confidence.

    Cleaning is done on hand screens and a small aspirator, which sounds quaint and is simply what works at this scale. Everything is dried in the loft over the shed to eight per cent moisture, then it goes into paper. No plastic anywhere in the packing, including the tape.

    Orders go out on Tuesdays and Fridays. In January and February that slips to Tuesdays only, because there are two of us and one of us is sowing.

    Practical things

    Postage, UK
    £3.20, free over £25
    Dispatch
    Tuesdays and Fridays
    Packing
    Paper, no plastic
    Germination test
    100 seeds, 14 days
    If it fails
    We replace it, no questions
    Trade and grower orders
    Half kilo on 12 lines
    Visits
    Open days, first Sunday in July

    If a packet does not come up for you, tell us what you did and we will replace it. Nine times in ten it is soil temperature and we will say so, but you still get the seed.