A flower farm without sweet peas just doesn’t seem quite right. We grow them every year with the first batch in the polytunnel flowering from the end of April through to early June. Planting the sweet pea seed really heralds the start of the new season for me, putting seed in the ground and watching it grow and climb through the coldest months of the year seems like a visual demonstration of faith that Spring will come, and with it the sweetest blooms.

This is how we grow our Spring Sweet Peas at Mill Pond Flower Farm in the Scottish Borders:

Dig a trench approx 8 inches deep in the polytunnel, where they will be able to climb to the highest point
Line the trench with food - I’ve used manure, homemade compost, comfrey leaves and this year it was pond weed. It just needs to be something to slowly break down and feed the plants over a long period. Don’t mix it in, just leave a deep layer.
Water well. Let the water sink in.
Add a layer of soil, a couple of inches.
Add the seed. You can pre-soak if you like but I don’t find it makes any difference.
Cover with 4-5 inches of soil. Don’t skimp on coverage.
Water generously.
Firm the soil well. This is really important as mice love love love sweet pea seed and will dig up and eat it.
Wait for the sprouts - it usually takes a couple of weeks.
Water only if it’s unseasonably warm and the soil is looking very dry
Wait till Spring, cut, sniff, appreciate! Oh, and sell them, don’t be tempted to fill your house with them all, no matter how great that would be.