As the warmer, wetter days of spring progress, snails and slugs become more active in gardens and nurseries, posing a serious threat to plant health. The increased moisture levels create the perfect environment for these pests to thrive, leading to plant damage if left unchecked. For horticulturists and landscape professionals, an effective mollusc management strategy is essential to maintain healthy and robust plants throughout the season.

Understanding the Threat

Snails and slugs belong to the phylum Mollusca and are more than just nuisances – they are voracious feeders that can quickly decimate seedlings, young plants, and delicate leaves across a wide variety of species. Of the 50 introduced species in Australia, around 10 have become serious plant pests. These pests are most active during cool, damp conditions, making spring a particularly vulnerable time for plants. While snails and slugs primarily feed at night, they can also feed during the day in prolonged wet weather. Their feeding leaves behind irregular holes (older snails) or skeletonisation (young snails) in foliage, along with snail droppings and a telltale slimy, glistening trail from mucous secreted by foot glands, which solidifies when exposed to air. Slugs, in particular, can consume their body weight in a single day!

In other countries, snails and slugs have been identified as carriers of tobacco mosaic virus and various fungal diseases, including Phytophthora, Fusarium, and rusts that affect European plants. In Australia and New Zealand, certain areas experience heightened activity during spring due to frequent showers, but all horticulturalists should be mindful of the risks these pests pose during the season.

Snails and slugs are hermaphroditic and lay eggs. Some snail species can hibernate or enter a resting stage for up to 3 years, while slugs do not enter a resting phase during dry or cold weather. It can take 1 to 2 years for them to mature into adults, and their lifespan varies, lasting several years or just months depending on the species.

Effective Snail and Slug Management Strategies

Cultural Controls:

Maintaining good garden hygiene is one of the first and most important lines of defence against snails and slugs. Removing debris, fallen leaves, and mulch that create moist hiding places can significantly reduce their populations. Keeping pathways and planting areas dry and clear will discourage these pests from establishing themselves. Proper irrigation management is also key - using drip systems instead of sprinklers and watering plants early in the day helps reduce the moisture that attracts snails and slugs. Regular monitoring is crucial, as these pests often hide during the day. Check for activity after 10 pm on mild nights or use traps and baits to assess population levels.

Chemical Controls:
For larger populations, chemical controls can be highly effective when combined with cultural practices. Products like SlugOut, Blitzem, and Metarex offer fast-acting relief by attracting snails and slugs away from plants. To maximise effectiveness, apply baits strategically around the base of vulnerable plants and in areas where snails and slugs are known to gather.

At Garden City Plastics, we offer a range of products designed to tackle snails and slugs effectively:

• Metarex: A superior loading of metaldehyde effective on snails and slugs. Metaldehyde kills snails and slugs by dehydration. Also renowned for its superior spreadability and rain resistance, ideal for larger gardens and nurseries.
• SlugOut: Another reliable choice of metaldehyde for snail and slug control, offering long-lasting protection.
• Blitzem: A lower strength of metaldehyde and a fast-acting bait that targets snails and slugs with precision. It contains a bittering agent to deter non target animals and pets from eating the pellets.

Organic Molluscicides:

For those seeking environmentally friendly options to control snails and slugs, organic molluscicides provide an excellent solution. Products like Eco-Shield offer effective control while being safe for beneficial insects, pets, and the broader ecosystem. These baits use naturally derived ingredients to disrupt the pests' feeding and reproductive cycles, ensuring long-term protection.

• Eco-Shield: An iron-based organic formulation, ideal for environmentally conscious professionals. It's safe for beneficial insects and pets, making it a great alternative to metaldehyde and methiocarb. Snails and slugs, which are highly susceptible to iron, stop feeding immediately after contact and retreat to die in their shelters. Eco-Shield also adds iron to the soil as it breaks down, making it harmless to pets and non-target animals.
• Copper Based products: Products like buffered complex copper and copper sulfate act as barriers and repellents for certain species of snails and slugs.
• Garlic Oils & Extracts: Organic options for creating a snail-proof barrier around plants, paths, and garden beds. While effective against certain species, some formulations are not recommended for edibles intended for immediate consumption.

Maximising Molluscicide Effectiveness

The most critical task in spring is bait application. Whether you opt for organic or chemical controls, proper bait placement and timing are key. It’s best to apply baits after watering in the evening when the soil is moist but not overly wet, as this encourages snails and slugs to emerge from hiding and take the bait.

For larger areas, spread the bait evenly, avoiding direct application too close to plants, as some products may harm young seedlings. Reapplication may be necessary, especially after heavy rain or irrigation.

Conclusion

Snails and slugs can be a persistent issue during spring, but with proactive management strategies, they don’t have to be. By combining cultural controls, regular monitoring, and targeted use of molluscicides, you can protect your plants and ensure they thrive despite increased pest pressure. Keep these practices in mind to safeguard plant health throughout the season and into the warmer months.

For more information or to order contact us at 1300 695 098 or sales@gardencityplastics.com

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