Your herb plant is standing on the kitchen counter looking droopy and withered. It looked so tempting again in the supermarket, where they are all so fresh, green and full of life. Only to wither into a brown mess in no time when you get them home. Why is it so hard to keep these plants alive?
‘The supermarket plants are grown in greenhouses,’ says Monique Bijlaard, a researcher at Wageningen Plant Research. The conditions for growth are optimal there, with warmth and plenty of light. Bijlaard: ‘It’s usually around 20 degrees in a greenhouse. After that, the plants go to the supermarket, where the conditions are different, and then you take them home, where the climate is different again. What is more, they are all stored close together in the greenhouse, which creates a microclimate around the plant that is different to when it’s on its own on the kitchen counter.’
There’s a different microclimate in a greenhouse than at home on the kitchen counterMonique Bijlaard, researcher at Wageningen Plant Research
All those sudden transitions are too much for the plants. But they are not intended to last long anyway, are they? Bijlaard: ‘These pots are intended to last a bit longer, but of course the grower benefits more if you buy a new plant before too long.’
Bijlaard has a few tips for extending the life of your herb plants. ‘The plants are used to absorbing water from below, so put them on a dish containing water and don’t pour water over them.’ The plastic around the plant may not be very attractive, but Bijlaard advises leaving it in place. ‘It protects the plant and provides it with its own microclimate.’ And then: when you cut leaves off the plant, leave the lowest pair of leaves on the stem. Then the plant stays the same size. And the leaves contain chloroplasts, which convert sunlight into energy for the plant so it can grow. The plant can’t do anything with stems alone. ‘If you let some leaves grow bigger, the plant will be more fragrant,’ explains Bijlaart. ‘And these leaves have more flavour too.’ And last but not least: put your plant in a warm place, at about 20 degrees, and make sure there is enough light. Direct sunlight is not good for the plant, because it burns the leaves. If you want to put the plant out of doors, you can do so in the summer, but don’t put it in full sun. For this purpose, you are better off buying plants grown outside, because they are already ‘hardened’.
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