a lot of docks growing in a field of grass

At What Stage of Growth Should I Spray Docks in Grassland? A Comprehensive Guide for Farmers

Docks (Rumex spp.) are a common and persistent weed problem in grasslands, posing a threat to agricultural productivity and overall pasture quality. Knowing the right stage to spray docks is crucial in effectively controlling their growth and preventing them from taking over your grassland. In this comprehensive guide, we delve into the optimal stage of dock growth to spray, the most effective herbicides, and best practices for achieving a healthy and thriving pasture.

Understanding docks in grasslands

Docks can be broadly categorized into two main species: broad-leaved dock (Rumex obtusifolius) and curled dock (Rumex crispus). These perennial weeds are known for their extensive root systems and rapid reproduction capabilities. The seeds produced by docks can remain viable in the soil for several years, making it crucial to address the problem early on.

The ideal stage for spraying docks

docks at the rosette stage 200mm across
When the docks reach at least 200mm across they are ready to spray.

For optimal control, docks should be sprayed when they are in the early stages of growth, which is typically during the rosette stage. This is when the leaves are close to the ground and form a circular arrangement. At this stage, docks are most susceptible to herbicides, as they are actively growing and have a larger surface area for the chemicals to work on.

Spraying during the rosette stage is usually best done in late spring or early summer when temperatures are consistently above 50°F (10°C) and there is no risk of frost. This ensures that the herbicides are absorbed effectively, leading to better control of the weeds.

Choosing the right herbicide

Several herbicides are suitable for controlling docks in grasslands, but it’s essential to choose the right one based on your specific needs and the surrounding environment. Common herbicides used for dock control include:

  • MCPA (2-methyl-4-chlorophenoxyacetic acid): A selective herbicide that targets broadleaf weeds, including docks, without harming grasses. It is most effective when applied during the rosette stage.
  • 2,4-D (2,4-dichlorophenoxyacetic acid): Another selective herbicide, 2,4-D is used for controlling broadleaf weeds in grasslands. It works best when applied during the early growth stages of docks.
  • Dicamba: This selective herbicide is often used in combination with MCPA or 2,4-D to improve the overall effectiveness of dock control.
  • Fluroxypyr: A selective herbicide that can be used to control docks and other broadleaf weeds in grasslands. Fluroxypyr is effective in controlling both young and mature docks.
a 2 litre bottle of doxstar herbicide
Doxstar is a popular dock herbicide- 2 litres covers 1 hectare.

Always read and follow the label instructions carefully when using herbicides. Some products may have restrictions based on the type of grass, grazing, or harvesting intervals.

Optimum weather conditions for spraying docks

The best weather conditions for applying herbicides like MCPA, 2,4-D, dicamba, or fluroxypyr to control docks in grasslands are as follows:

  1. Temperature: Ideally, the temperature should be consistently above 50°F (10°C) during the day. Herbicides are absorbed more effectively by actively growing weeds at these temperatures, leading to better control.
  2. Wind: Light wind or calm conditions are preferable when spraying herbicides. Strong winds can lead to spray drift, affecting non-target plants or areas and reducing the efficacy of the application.
  3. Humidity: Moderate humidity levels are ideal, as they help maintain the herbicide’s effectiveness on the weed’s leaves. Extremely low humidity may cause the herbicide to evaporate quickly, while high humidity may result in reduced absorption.
  4. Rain: There should be no rain forecast within 24 hours of application. Rainfall soon after spraying can wash away the herbicide, reducing its effectiveness in controlling the target weeds.
  5. Cloud cover: Overcast or cloudy conditions can be suitable for spraying, as long as the temperatures are within the appropriate range and there is no risk of rain. In some cases, these conditions may even enhance herbicide absorption by reducing evaporation.

It’s essential to closely monitor weather conditions before and during herbicide application to ensure optimal results and avoid any unintended consequences to the surrounding environment or non-target plants.

Best practices for spraying docks

To ensure the best results when spraying docks in grassland, consider the following best practices:

These docks were sprayed four days ago and are beginning to wilt and roll their leaves inward.
These docks were sprayed four days ago and are beginning to wilt and roll their leaves inward.
  • Target early growth stages: As mentioned earlier, it is vital to spray docks during the rosette stage for the most effective control.
  • Use the correct application rate: Follow the recommended herbicide application rates and calibrate your sprayer accordingly.
  • Monitor weather conditions: Ideal spraying conditions include light wind, no rain forecast within 24 hours, and temperatures above 50°F (10°C).
  • Regularly scout your fields: Regularly inspect your grassland for the presence of docks and other weeds. Early identification and treatment can prevent them from becoming a significant problem.
  • Practice good pasture management: Regular grazing or mowing, maintaining soil fertility, and avoiding soil compaction can help minimize dock infestations in your grass


To effectively control docks (Rumex spp.) in grasslands, it’s essential to spray them during the early rosette stage, which usually occurs in late spring or early summer. Choosing the right herbicide, such as MCPA, 2,4-D, dicamba, or fluroxypyr, is crucial for successful dock control. Adhering to best practices, such as using the correct application rate, monitoring weather conditions, and regularly scouting your fields, can ensure optimal results. Additionally, maintaining good pasture management techniques can help prevent dock infestations and promote a healthy, thriving grassland.