Thermal weed control: an effective alternative to chemicals?

Weeding is part of the essential gardening work, whether in the vegetable patch, the pleasure garden or in the alleys. For too long we have abused toxic and polluting weedkillers to which we are paying a heavy price today at all levels. Fortunately, there is an alternative to these chemicals for weed control, which is thermal weed control. Let’s see together what it is, if it is as effective as it is said and what are the different models of thermal weeders.

Thermal weed control: how does it work?

It’s about a weeding technique which consists of eliminating unwanted plants without any chemicals since it relies on the use of heat. The principle is therefore simple, the thermal shock having the effect of destroying the plant cells, the membrane of which bursts under the effect of the high temperature. The drying out of a plant is obtained in a few hours because the water contained in the cells escapes.

The Thermal shock can be obtained by pouring boiling water on a weed or by exposing the plant to a flame. Extremely simple, however, the heat treatment implies having to repeat the task two or three times to be perfectly efficient. This indeed makes it possible to completely exhaust the plant and therefore to kill it. This is how we manage to eradicate 100% of unwanted weeds since they can no longer grow back.

Thermal weed control: excellent results in just 2 seconds

Some novice gardeners cannot be satisfied with this alternative to pesticides because they’re just not doing the right thing.

Just expose the unwanted weeds to this strong heat stroke for only 2 seconds at most. At first glance, nothing seems to be happening. But a few hours later, or at most in three or four days, all the plant parts are totally dried out, which includes the roots.

This exposure time, which must not exceed 2 seconds, must be respected and this is the whole secret of the efficiency of thermal weed control. If we expose the plant to heat for a longer period of time, we obtain a burning. And this is precisely what must not be done because, as paradoxical as it may seem, the burnt plants will heal in the parts that have remained intact and will grow back more becoming, suddenly, more invasive still. Insisting on unwanted weeds with a thermal weed killer is therefore a false good idea since we obtain the opposite result to that expected!

Certainly there are “weeds” tougher than others, which can only be destroyed after two or three passages of the thermal weeder. This is the case, for example, with dandelions and other plants with taproots, or even quackgrass. Likewise, ivy is a creeping plant which can be very invasive and which can be exterminated by this process provided it is pass several times a few days apart because of its great resistance. But we do not exceed 2 seconds at each session.

Never mind, patience is worth it since you get an excellent result without any chemicals. It is only by theplant depletion that we can destroy it. And you might as well not let the weeds grow because it is on the young plants that thermal weed control is most effective.

Electric or gas thermal weed burner: main characteristics

This weeding process has undeniable advantages and requires the use of a suitable device. We find in the signs dedicated to gardening two main families of thermal weeders, to know :

  • The electric thermal weeders : the hot air they propel is of the order of 600 ° C. They require an electrical outlet nearby. These models are sold between 70 and 90 € and are suitable for small areas to be weeded. The price range is between 40 and 110 €.
  • The gas thermal weeders : fitted with a cartridge (Propane or Butane) or, for professional models, coupled to a gas cylinder. Some of these models expose plants to a temperature of 1,200 to 1,400 ° C. Their autonomy varies between 3 and 6 hours. There are even some which are equipped with a bottle holder trolley. It takes between 250 and more than 600 € for this type of thermal weed control device.

Regardless of the model chosen, an electric or gas appliance should be used with caution in areas particularly exposed to the risk of fire.

You should also know that plants located in the immediate vicinity of the grasses that you want to eradicate are also exposed to the heat given off by a weed killer. Be careful, therefore, if this alternative to chemicals is used in the vegetable garden or flower beds. It is therefore recommended to use a hoe or, quite simply, weed manually in order to preserve the plants that one wishes to preserve.