Battling Mildew: Treatments and Prevention

Battling Mildew: Treatments and Prevention for Plants and Fruit Trees

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Introduction

In this article, we will look at strategies for battling mildew; including treatments and prevention for plants and fruit trees, to help you protect your plants and harvests.

Mildew, the bane of our plant’s lives in damp weather : Tomatoes, Potatoes, Peas, Courgettes, Apple trees, Roses … all are susceptible.
For tomatoes and potatoes, rain showers during hot weather, or a sudden change in temperature can provoke mildew.

Mildew, which is a common fungal infection, can wreak havoc on plants and fruit trees, leading to reduced yields and poor plant health. However, with the right knowledge and timely action, it is possible to treat mildew and reduce its effect.

Understanding Mildew and Powdery mildew

Mildew and Powdery mildew on tomatoes and potatoes are caused by various species of fungi that thrive in warm and humid conditions. They appear as powdery white, gray or even black patches on the leaves, stems, and fruits of plants and fruit trees. The fungi responsible for mildew typically spread through spores, which can travel long distances, mostly by wind dispersion, making early detection and swift action vital.

Treatment Options

1. Neem Oil:

Neem oil is a natural and effective treatment for mildew. Its antifungal properties can combat the fungal infection and prevent its spread.
Dilute Neem oil in water as per the manufacturer’s instructions and spray it directly on the affected areas. For best results, repeat the application every 7 to 14 days until the mildew is under control.

2. Baking Soda Solution:

Baking soda (Bicarbonate of Soda) is a readily available household remedy for mildew.
Make up a mixture of :

• one tablespoon of baking soda,
• one teaspoon of mild liquid soap,
• and 3.75 litres (one American gallon) of water.

Shake well and spray the solution on the infected plants. This solution alters the pH (level of acidity) on the plant’s surface, making it less hospitable for the mildew to grow.

3. Milk Solution for Powdery mildew:

Studies have shown that a diluted milk solution can be effective in treating mildew.
Mix one part milk with nine parts water and apply it to the affected plants. The proteins in milk act as a natural fungicide, helping to inhibit the growth of mildew. This seems to work well on the squash family (Curcubits) of plants, including cucumbers.

4. Savory Essential oil:

This is an alternative which I have not yet tried and that is essential oils. It is claimed that a spray made with Savory (Sarriette) essential oil will prevent mildew.

Here is a common recipe for 1 litre of essential oils spray:

10 ml of rape-seed (colza) oil.
About 20 drops of Savory (Sarriette) essential oil.
1 soup spoonful of liquid Savon de Marseille (detergent free)
Make up to 1 litre with rain or bottled water.
Mix well.

The advice is to use not more than once a month in the early morning before the sun gets onto the plants.

5. Copper or Sulphur-based fungicides :

Commercial fungicides are available in many supermarkets and garden centres and can be used to treat mildew. The main commercial products for both prevention and treatment are based on Sulphur or Copper.

For fruits, tomatoes, potatoes and apple trees the norm is Bordeaux mixture (Bouillie Bordelaise), or a Copper-based spray which is used on apple trees during winter treatments.

For roses, solutions based on Sulphur or Copper, used for probably a century now, are the common proprietary products. The downside is that there will always be a residue left on the plants.

Always follow the product’s instructions and avoid using them during the heat of the day to prevent leaf burn.

Preventive Measures

Proper Plant Spacing:
Ensure adequate spacing between plants and fruit trees. Good airflow reduces humidity levels around the plants, making it less favourable for mildew development.

Watering Techniques:
Overhead watering can lead to increased humidity on the plant’s surface, creating an ideal environment for mildew. Opt for drip irrigation or water the plants at the base to keep the leaves dry.

Pruning and Cleaning:
Regularly prune affected plant parts – disinfect all tools between each plant – and remove fallen leaves from the ground but do not put them in an ordinary garden composter. This helps eliminate potential sources of spores, reducing the chances of mildew recurrence.

Fungicide Applications:
As a preventive measure, consider applying fungicides labelled for mildew control before the symptoms appear. Always read and follow the instructions carefully when using any treatments.

Plant Resistant Varieties:
This means choosing F1 plants or seeds. Here at La Rabine Jardin, we prefer to grow old, non-F1 varieties of plants. In this way, seeds from a single variety of plant can be saved for growing and planting the following year. In this way, you can keep varieties of plants ‘true’.

There is no point in saving the seeds of an F1 plant to grow for the following year as they will not ‘come true’. F1 seeds cannot produce the same plant variety because an F1 plant has been specifically bred by cross-pollinating 2 different hand-picked plants to create a new plant. Therefore, the only way to get the same F1 plant variety is to either buy F1 seeds, or F1 plants every year.

If mildew is a big problem for you in your garden, whenever possible, choose plant varieties that claim to be naturally resistant to mildew. These varieties have genetic traits that make them less susceptible to fungal infections.

To sum up:

• Mildew can be a persistent nuisance for plants and fruit trees, but its effect can be reduced with timely treatment and preventive measures.
• Using natural remedies like neem oil, baking soda solutions, and milk mixtures can be both eco-friendly and efficient in combating mildew.
• Additionally, maintaining proper plant spacing, watering techniques, pruning, and opting for resistant varieties will help to prevent mildew outbreaks.
• Remember to keep an eye on all your plants regularly during warm, humid and autumnal conditions as mildew can strike literally overnight!

By adopting a proactive approach and implementing the strategies suggested in this article, hopefully you can manage mildew attacks more effectively.