Gadenin日本語Get the appStart cutting once the stems reach 6 inches
Watercress is ready as soon as there is something worth cutting, which is usually when stems reach 6 inches (15 cm) with several fully expanded leaves. From a pot started from cuttings in spring that is around four to six weeks. There is no point waiting for size, because the leaves get coarser and hotter as the stems age and the plant puts its energy into running upward.
The best leaves come from young side shoots, not from the main stem. That is why cutting is also the way you manage the plant: every cut forces branching, and a pot cut regularly from early on stays low, dense and mild, while an uncut pot becomes a handful of tall stems with hot leaves and nothing underneath.
- Cut, do not pull Pulling a stem drags the whole clump and lifts roots out of a pot that is standing in water. Use scissors or snips and cut cleanly. A torn stem base also sits in wet compost and rots back into the crown.
- Cut above a leaf joint Leave the cut about a quarter inch (5 mm) above a pair of leaves. New shoots come from the buds in those leaf joints. A stem cut in bare space between joints dies back to the next joint down and wastes a fortnight.
- Leave two or three joints on every stem Never cut a stem to the compost. Leaving two or three leaf joints on the stump keeps enough leaf on the plant to power the regrowth. A clump cut flat regrows slowly, if at all.
Take a third at a time, not the whole pot
The tempting mistake is to harvest a pot the way you harvest a bag of salad leaves, cutting the lot and expecting it back. Watercress can do that once, in cool weather, but a clump stripped in warm weather often simply sits and sulks while the bare stems in the wet compost start to brown at the base.
Take no more than a third of the standing growth at any one cut, working across different parts of the pot rather than shaving one side. With two pots on a rotation you can cut one while the other recovers, and a small pot then produces a useful handful every week through spring and autumn.
| Season | How much to take | Regrowth time |
|---|---|---|
| Spring | One third | 7 to 10 days |
| Early summer | One quarter | 10 to 14 days |
| Peak summer heat | Tips only, or none | Slow; the plant is under stress |
| Autumn | One third | 10 to 14 days |
| Winter indoors | A few sprigs | 3 to 4 weeks |
If regrowth after a cut is thin and pale rather than dark and branching, you took too much or the water in the tray has been standing. Change the water, feed at half strength once, and do not cut again until the new shoots are dark green.
Cut in the morning and get it into cold water
Watercress wilts faster than almost any other salad leaf because the stems are hollow and full of water. Cut in the early morning while the plant is still turgid and it stays crisp for hours; cut at midday in summer and it is limp before you reach the kitchen. If you have to cut on a hot afternoon, carry a jug of cold water out and put the stems straight into it.
Indoors, treat a bunch like cut flowers rather than like a bag of leaves. Stand the stems upright in an inch of cold water in a jar, cover the top loosely with a bag, and put the whole thing in the fridge. Kept that way it holds for four or five days. Sealed flat in a bag it goes yellow and slimy in two.
- Wash in a bowl, not under the tap Swish the bunch in a bowl of cold water and lift it out, leaving grit at the bottom. A running tap batters the leaves and bruises them, and bruised watercress blackens overnight.
- Do not soak for hours A few minutes in cold water crisps the stems. Left soaking, the leaves take up water, go translucent at the edges and lose their pepper.
- Dry before storing Shake the bunch out or spin it briefly. Surface water on the leaves in a closed container is what turns a bunch slimy; water at the cut ends is what keeps it fresh.
Taste tells you when you have left it too long
Mild, slightly nutty pepper is watercress at its best. When a cut tastes fiercely hot and the stems feel stringy, the plant has been warm, dry at the root, or is starting into flower. The heat is not a fault you can wash out, and it will not improve on the plant, so cut the whole hot section away rather than picking through it.
Once a stem has produced flower buds, its leaves stay hot and small no matter what you do to it. Cut those stems out at the base of the flowering shoot and let the clump send up new growth from lower down. The flowers themselves are edible and pleasantly peppery scattered on a salad, so a flowering stem is not wasted even though its leaves are past their best.
| What you taste | What it means | What to do |
|---|---|---|
| Mild pepper, crisp stems | Growing well in cool conditions | Keep cutting on the same rhythm |
| Harsh heat, tough stems | Heat stress or the start of flowering | Move to shade, cut the old growth away |
| Almost no flavor, floppy leaves | Too little light or too much feed | More light, stop feeding |
| Bitter with a sour smell | Stale water in the tray | Change the water daily and cut off the affected growth |
Keep the season going with a second pot
One pot cut hard in spring will be tired by midsummer. The cheapest way to have watercress from spring to hard frost is to start a second pot from cuttings taken off the first one in early summer, and a third in late summer for autumn and a windowsill in winter. Cuttings root in a jar of water in about a week, so the cost of a replacement pot is nothing but time.
Record the date of each cut and roughly what you took, along with the date you started each new pot. After a single season those notes show you exactly how many weeks a pot stays productive under your conditions, and therefore when to start the next one so you never have a gap.
A pot that has flowered and gone woody is finished as a salad plant. Take clean tip cuttings from it while there is still soft growth, then empty the pot and start again rather than trying to nurse the old crowns through.