A salad leaf that's easy to grow, packs a powerful bite, and fills the gaps while slower crops get going sounds great, doesn't it? So how come only children grow it?
Cress suffers something of an image problem. There's no doubt that growing it on the windowsill is a great way for youngsters to learn about germination, but we seem to have forgotten that there's more to it than skinny white stalks topped with a couple of immature leaves.
Growing cress with children
First, though, back to basics. The easiest way to grow cress quickly is to find a shallow tray (a plastic food container from the supermarket serves well) and line it with paper tissues, cotton wool or kitchen roll. Wet the paper or wool well (though don't have it swimming in water), sprinkle seeds over the surface and cover the tray with cling film. A container that's around an inch or two deep is perfect, as this allows space for growth before the seedlings hit their heads on their "glass ceiling".
Germination takes place within a couple of days (24 hours, if you're lucky) and the cress is ready to harvest when it's around 1½ to 2 inches high (which will be, depending on the type you're growing, five to seven days later). Snip the stalks off at the base to use as a garnish, in a salad, or in sandwiches.
It's important to ensure that the kitchen roll, or whatever you're using, doesn't dry out, which is why cling film is so useful as it stops evaporation. You can grow the cress without covering with cling film, but you have to keep a strict eye on it as the paper/wool etc dries out very quickly.
An alternative to the kitchen roll method is to sprinkle them onto the surface of a three-inch pot (or larger) full of damp compost. This is the way to go if you want to grow the little seedlings on further, as they'll soon need the nutrients in the soil to progress and will starve on kitchen roll.
Growing grown-up cress
I don't really see the point of growing cress only to scythe it down when it's barely got going, and I'm moderately confident that, once you've tried the grown-up version, neither will you.
The great thing is that cress is something that you can grow on the windowsill all year round, or sow directly into outdoor beds any time frosts have passed. Seeds can be sprinkled over the surface of a pot or sown in the ground in either a block or row, quite close together (say half an inch or 1 cm apart). If cress becomes too hot and dry, it tends to bolt, so it's a good choice for an area that's a bit shady and, for best results, it needs to be grown in soil that remains moist. Because it grows so quickly, it's ideal for intercropping.
The choice of cress can be quite confusing, especially as the pictures on seed packets tend to look pretty similar but appear under various names such as Common, Curled or Greek Cress. To be honest, they are all pretty similar. In my experience, larger leaved varieties tend to be slightly milder. There's also one called Sprint, which does live up to its name and germinates just a touch faster than others.
The true leaves of cress are feathery and divided and plants grow to around six inches high in about four weeks. Leave it longer and it will begin to go to seed, but if this happens don't just throw them out. The fire in the leaves will have died down, but they're still tasty and the tiny white flowers are also edible and provide a tiny mustardy explosion in the mouth. If you harvest by snipping stalks just above a leafy growing point, they may produce a second flush of leaves, but my experience is that cress isn't very keen to regenerate. Sowing a new batch is a better way to keep cress in production.
So, I hope I've convinced you. For the effort of sowing a few seeds that would otherwise provide about enough garnish for a cheese sandwich, you will, by letting cress grow, gain handfuls of leafy growth. Cress tends to lose its flavour when cooked, but it certainly adds texture and a mustardy warmth to any salad.
By Helen Gazeley