I think it’s fair to say that the Scottish Borders, where I come from, is not renowned for its culinary heritage. Only one Borders dish, as far as I know, is held in high regard, and that is the delightfully-named ‘rumbledethumps’.
Rumbledethumps is a literal mash-up of leftover potatoes, cabbages, and often onion or chives too, topped with cheddar cheese and eaten as a main course or as a hearty side for meat. In my opinion, the very best rumbledethumps is made using sweet and tender spring cabbage.
Planting Spring Cabbages
A common misconception about spring cabbages is that they should be sown in spring. Actually, they're one of the slowest maturing types of cabbage, being sown in late summer for a harvest next year. They put on a growth spurt as the weather warms up in spring, providing an early crop of tender greens when not much else is available in the vegetable garden. Spring cabbages are usually pointed varieties such as 'April’ or 'Caraflex’, but you can now find round-headed types too.
So, in anticipation of next year’s rumbledethumps, I have recently made my first sowing of spring cabbages, directly into a spare bit of soil. In a few days I will make a second sowing in a module tray in the greenhouse as insurance against the birds, voles and slugs that might feast on the emerging seedlings outdoors.
Spring cabbages have excellent germination rates in the warm summer soil, though in really hot areas you might need to provide some shade. Once the seedlings have about four to six leaves, transplant them into the bed they’ll stay in for the rest of their short lives. It pays to plan well in advance where your spring cabbages are going to grow, because despite their name they may well be there right up until early summer next year.
(Your ideal timings for sowing and transplanting spring cabbage will vary depending on your location – handily, our Garden Planner can recommend the best times to sow and transplant in your area.)
Spring cabbages grow best in firm ground that hasn’t recently been dug or loosened with added compost or manure. Before planting, tamp down the soil with the back of a rake or even your feet, depending on how heavy or loose your soil is. Rake lightly, and then transplant your spring cabbages into it. For small heads or spring greens, you can space cabbages as closely as 30cm (1 foot) apart. Plant them just up to level of the lowest leaves, and firm them in well.
Low-Maintenance Overwintering Cabbages
Spring cabbages make a great low-maintenance overwintering crop. They’re pretty cold tolerant, only needing draped with horticultural fleece if the weather dips to really frigid levels – below about -10ºC (14ºF).
As with other brassicas, it’s worth netting your cabbages to exclude insect pests and to keep hungry birds from shredding the leaves like confetti in the depths of winter. Make sure that any frame or netting used is robust enough to withstand the weight of fat pigeons sitting on it (I speak from experience!). A hooped design will shed a lot of snow.
And that’s pretty much it. Keep your cabbages watered until they establish, hoe around them if necessary and forget about them until early spring, when they will be hungry for a top-dressing of some organic fertiliser. Homemade or bagged compost, chicken manure pellets or similar will give them the energy they need to burst into growth once more. They’ll be ready to harvest from mid-spring onwards.
Harvesting Spring Cabbages
The great thing about spring cabbages is their versatility. They can be picked young and loose-leaved as spring greens, left for longer to produce dense heads – or both!
To get the earliest harvest, pull up half your crop as spring greens while the leaves are still loose and tender. Leave every alternate cabbage to swell and grow into the space your spring greens have vacated. They’ll develop sweet, crisp heads.
You can even double-crop your spring cabbages if your soil is rich and conditions are favourable. Take your first harvest from the plant, either as spring greens or as a headed cabbage, but instead of pulling up the whole plant, cut the leaves or head off just above the lowest set of leaves. Use a sharp knife to cut a cross shape in the top of the remaining stump. This is the point from which the plant will regenerate. In time, you’ll be treated to a second crop in the shape of a cluster of mini cabbages.
Easy Spring Cabbage Recipe
Now back to rumbledethumps! For the curious, simple-to-make rumbledethumps is a leftovers recipe really, so use what you have – spring greens or headed cabbages will both taste delicious. Mix equal quantities of mashed potato with boiled or sautéed cabbage or spring greens, plus a chopped, sautéed onion or a handful of chopped chives, and season to taste. Pop it in an oven-proof dish and grate cheddar over the top. Bake it until the top has browned and the cheese has melted. What better way to enjoy your fresh spring cabbages than in this delicious Scottish classic? Yum!