Cut and grow again
Baby Kale var. Red Russian being harvested as a cut-and-grow-again system
Most vegetable gardeners growing leafy vegetables will have heard the term ‘cut-and-grow-again’. As a harvesting technique the term is often poorly understood, and many gardeners may not appreciate quite how useful the system is – especially if they have just a small piece of land.
Any vegetable that is picked for its leaves can be harvested under a cut-and-grow-again system. This includes vegetables that most people would not consider suitable, such as kales, cabbages and hearted lettuces, as well as those that have become associated with the system like leafy lettuces, oriental greens, chards and perpetual spinach.
Leafy crops suitable for harvesting under a cut-and-grow-again system: Oriental leaves and chard var. Bright Lights
Leafy vegetables have one active growing point at the centre of the plant where the leaves of the plant are produced. When harvesting these vegetables a gardener must choose where to cut. A cut made at the base will remove the whole plant including the central growing point. This is a single harvest approach typical for cabbages and hearted lettuces. With the growing point gone, all that remains is to clear the remaining stump to make space for the next crop.
A single harvest approach - cutting below the growing point
But that same gardener, poised over the crop with the knife, could make the cut just a little higher above the plant’s main growing point. After a successful cut-and-grow-again harvest a sizeable handful of loose leaves will be picked, while the growing point will remain undisturbed. A close inspection of the remaining plant will reveal several tiny, immature but perfectly formed leaves, and right in the very centre the growing point. Undamaged by the harvest the growing point will continue to produce leaves, and with nothing to impede their growth the miniscule leaves will quickly grow into full-sized leaves. In good growing conditions a spinach, lettuce or parsley plant could have enough new green leaves to be harvested again within just a few weeks. With no work at all – no seed to sow or new plants to tend – and at a fraction of the time there are more young, tender leaves ready to eat for another meal.
Red Salad bowl lettuce: uncut, loose leaves just cut and regrowth after a cut-and-grow-again harvest
Pak choi var. Joi Choi: full sized head; just harvested under a cut-and-grow-again harvesting system; regrowth
Mizuna: just cut, regrowth and fully mature plants
All this depends on the gardener cutting above the growing point so it helps to know exactly where that growing point is situated. How can that spot be identified? Quite literally it is at the centre of the plant, just above the point where the smallest leaves are attached. Normally this is quite close to the ground, but it does vary depending on the type of vegetable and its maturity.
Little gem lettuce var. Bubbles cut in half to show the postion of the growing point.
It is easy to tell if a cut has been made too low: if any harvested leaves, even just two of them, are attached at their base then the growing point has been removed and the vegetable’s regrowth ability has been seriously impaired.
Perpetual spinach: growing crop and loose leaves of perpetual spinach harvested by a cut-and-grow-again system.
There is no rule about how often leaves should be harvested under a cut-and-grow-again system, but there are some basic guidelines to help a gardener decide. A general rule-of-thumb is to let the vegetable develop a decent amount of leaf before taking a cut, but not to wait so long that the quality of the older leaves start to deteriorate.
Managing a bed
If managed well a cut-and-grow-again crop is highly efficient, continuously producing green leaves that are generally better quality and available over a longer harvest period than the same crop picked as individual plants. The trick is to start harvesting early, when the plants are still quite young. At the next, and each subsequent, harvest cut the neighbouring uncut plants, but do not be tempted to take more than is required.
A bed of curly parsley var. Bravor (left) and pak choi var. Joi Choi (right) managed under a cut-and-grow-again harvest system
All good things come to an end
Unfortunately, even the best things come to an end. Eventually, the growing tip stops producing leaves and switches from a vegetative to a flowering stage. When this happens the plant has become reproductive, and will start to ‘bolt’, i.e. leaf production has stopped, the stem will elongate and a flower will emerge.
The length of the vegetative stage depends on the vegetable. For instance parsley and perpetual spinach, which are biennials, will produce new leaves throughout a growing season, and will only start to flower after having gone through a winter. Other crops, such as lettuces, coriander, rocket and oriental leaves, which are annuals, have different triggers to becoming reproductive and will have a much shorter growing period.
To the gardener, the first visible sign of the flowering stage is when the vegetable starts to elongate. As soon as a gardener notices the first signs of bolting the game is up, and now is the time to sow another crop.
Bolted crops of pak choi (left) and perpetual spinach (right)
After the crop has bolted the only thing to do is clear the bed
© Joy Michaud