How to get rid of weeds in your greenhouse?

In this edition of the Growing tips and Advice we will cover a common issue in cultivation: weeds. First, we’ll describe what makes a plant a weed. Secondly we’ll cover what the presence of weeds can mean for you cultivation. And finally, we’ll talk about ways to fight weeds in your greenhouse.

This article tells you all there is to know about the management of weeds in your greenhouse. Are you looking for a little more background information about different types of weeds and the main possible sources of contamination at your site? Have a look at our previously published article “What are weeds?” first. Now, let’s see the what harm the presence of weeds can actually cause to your crops.

The effects of weeds on your cultivation

All of these properties can cause significant problems in growing. Dealing with weeds always requires extra effort and time and causes an increase in the costs of production.

Influences of weeds on your cultivation:

• Weeds can spread diseases and host pests. This can jeopardise crop health.
• The presence of weeds can cause a decrease in yield (both in quality and quantity).
• Weeds need nutrients and water to grow. Because the weeds take these out of the same resources as you cultivated plants, the growth and health of your cultivation is in distress.
• Weeds can lower the temperature of the crop canopy, which causes an extending growing period of cultivated crops.
• Finally, but not less important, weeds also affect the appearance of your crops. Which is of course not desirable when you grow ornamental or flowering plants.

How to fight weeds?

Banning all weeds from your premises is practically impossible, but you can limit their presence to a bare minimum. To do this, you need to start acting long before the first weeds pop up at your site. In other words, you need an integrated weed management and prevention plan.

You should make sure to have control over all possible sources of propagules and make sure not to create perfect conditions for weeds to grow and spread within your premises. Follow these general steps to minimise the presence of weeds in your growing sites:

• Integrated management starts at the gate of the farm. Here you need to monitor, measure and inspect all inputs coming into your facilities. Prevent the spread of pest, diseases and propagation materials;
• Farm premises needs to be clean and tidy to limit the amount of places for weeds to grow;
• Weeds need to be kept under control by mechanical removal (in severe cases possibly chemical treatment);
• Inside of production areas, weeds need to be removed as soon as they appear. If you act before they start flowering, seeding and replicating you limit the spread of weeds;
• Only use certified and clean materials, from selected sources with the ability to trace it back to the source.

Fighting weeds in the greenhouse

A greenhouse offers a specific environment with controlled growing conditions (depending on equipment and technology). It is more or less isolated from the outside conditions and influences. They also ask for specific points of attention to best control the spread and growth of weeds. We’ll sum up some of the basics for the successful management of weeds in your greenhouse:

• Scout the premises on a regular basis, identify hotspots and acting accordingly. Specific areas you should check include:
  • Equipment: It’s important to always have equipment that is not damaged and doesn’t malfunction.
  • Ventilation nets are one of the most important items to regularly inspect as they cover the biggest entrance areas of the greenhouses.
  • Doors: It is good practise to have different types of curtains at all entrances to your greenhouse.
  • Floors: Make sure your floor covering is undamaged. Damaged floors often allow material to be trapped there, creating perfect places for weeds to grow.
• Mechanical removal of weeds in early development stages.
• Chemical control is becoming more and more restricted, especially during the growing period. Make sure to only apply it in severe cases and to only use safe herbicides. Always make sure to take high protective measures.
• Thoroughly clean everything when emptying your greenhouse and during crop rotation.
• Not only clean and remove within the greenhouse. Also include the area around your premises and greenhouse.
• Regularly check the quality of your materials used for growing.

By applying proper weed management you should be able to limit the influence of weed related problems on your cultivation. If you need any assistance or advice on this topic, please contact your local distributor.