Our horticultural engineers answer numerous technical questions from amateur gardeners all year round. Many questions come back time and again because their answers are important for work in the garden or on the patio. You can find the most important questions here.

all answers show / hide

  • What are beneficial nematodes?

    Nematodes are very small roundworms that can be found in almost every ecosystem on earth. Some species of these tiny creatures are predatory and can be utilised in horticulture for the control of many soil bourne pests.

  • How do nematodes work?

    Nematodes kill larval pests, thereby stopping the damage they cause to plants and lawns. They first enter the pest larvae and inject it with bacteria, causing death. Nematodes will then eat the dead body, multiply, and immediately start searching for a new host. Once their source of food is exhausted the nematodes will themselves die, leaving behind no evidence of them ever being there.

  • How do I identify which product I need?
    • Damage to plants in pots with small white grubs in the soil – Vine Weevil larvae
    • Damage to the lawn – it can look like malnutrition or in need of over seeding - with small white grubs with pincers in the soil – Chafer Grub
    • Damage to the lawn – it can look like malnutrition or in need of over seeding - with brown / black grubs without pincers in the soil - Leatherjacket
  • Do the Neudorff nematodes also work against other pests?

    VineWeevilFree Nematodes and ChaferGrubFree Nematodes also work against: Fungus gnats, Cucumber beetle, Bagworm, Gall midge, Repels ant larvae. LeatherjacketFree Nematodes also work against: Wireworm, Caterpillars, Strawberry root weevil, Codling moth, Leaf miners.

  • How long will nematodes take to work?

    They can start working immediately but it may take some time for full results to be seen. Nematodes thrive in moist soil at temperatures between 10 and 30 °C, so the longer conditions remain in this range - the more effective they will be.

  • Are nematodes safe to use around children and pets?

    Yes, nematodes are child and pet friendly.

  • Do I need to refrigerate Neudorff nematodes?

    No, Neudorff nematodes do not need to be refrigerated due to being placed in n a state called ‚cryptobiosis‘ which prevents them from moving or using oxygen. They can remain alive in this state for up to 6 months.

  • How many times do I need to apply the product?

    Depending on the level on infestation, once can be sufficient but twice within a season may be necessary. Detailed instructions can be found within each product.

  • What are the optimum weather conditions for the application for nematodes?

    Between 10- 30 °C but not during bright sunshine. ldeally apply in the evening or on cloudy/ overcast or rainy days.

  • I have purchased my nematodes, when should I apply them?

    Apply early in the morning or dusk when temperatures are cooler and it is not full sun conditions (UV rays kill nematodes!). We advise application on rainy, overcast days for optimal nematode soil penetration. Do not apply in full sunlight!

  • How long do I need to mix / shake / agitate the sachet in water?

    Between 1 -3 minutes until the water becomes cloudy / milky, this will indicate the nematodes have diffused out of the bag and are now in solution with the water. Do not over shake as this will cause the sachet to break and the carrier material inside it will then likely block the sprayer / watering can head.

  • What temperature should the water be for mixing?

    The water for diffusing the sachet should be tepid. Very cold or very hot water should be avoided. The water coming through the hosepipe, if using a NemaSprayer, is suitable for use straight from an outdoor tap. Water hardness / softness will not affect the efficacy of the nematodes.

  • How do I apply the product in a watering can?

    We recommend the VineWeevilFree nematodes are applied via a watering can fitted with a coarse rose (1mm aperture opening minimum) although a NemaSprayer can also be used – please see instructions below. Firstly, in a bucket make a stock solution with 1.5 L of water and 1 x VineWeevilFree sachet. Mix vigorously for 1 - 3 minutes until the water has become cloudy / milky. Immediately take 0.5 L of this solution and add to a 4.5 L watering can and fill with water. Apply this solution to a third of the soil area to be treated. Repeat the process twice more so that all the stock solution has been used and the entire soil area treated. Remove used sachet from the stock solution bucket and dispose of either in the compost heap or in household waste.

  • How do I apply the product in a NemaSprayer?

    We recommend the LawnGrubFree and LeatherjacketFree products are applied via a NemaSprayer for ease of complete lawn coverage. To apply across an area of 100 m² fill the NemaSprayer to the 70 L mark and drop in 2 x LawnGrubFree / LeatherJacketFree sachets. Seal the sprayer securely and shake for 1 - 3 minutes until the water has become cloudy / milky. Attach the sprayer to your hose and switch on tap, turning the water lever on the NemaSprayer to ‘ON’. Water lawn with the solution until the NemaSprayer liquid chamber is empty. Remove used sachet from the NemaSprayer and dispose of either in the compost heap or in household waste. For the application of the VineWeevilFree product simply follow the above steps but only fill the NemaSprayer to the 30 L mark.

  • Should the soil be moist before and after the nematode application?

    The soil should be moist at time of application and lightly watered immediately after application. After application, regular watering of the treated area will provide sufficient moisture. Keep treated area moist for at least 3 days after application. In hot conditions, keep treated area moist for 7 days.

  • The sachet has not dissolved / the sachet is still inside the sprayer and the nematodes are still in the sachet?

    The sachet will not dissolve at all, it works like a tea bag with the nematodes ‘diffusing’ out of the sachet when mixed in water. When the water turns milky / cloudy the nematodes have diffused out of the sachet, the gel-like carrier material contained within the sachets does not dissolve – this is simply the carrier for the nematodes and not the nematodes themselves. Nematodes are microscopic so you will not see them in the water or the sachet – even though there are between 5 and 10 million of them per sachet! (product dependent).

  • ls it normal for residue to be left in the sprayer and what should I do with it?

    Yes it is, this residue should be removed after application is complete and disposed of as household waste.

  • Are these pellets (Sluggo® Slug and Snail Killer+*) really wildlife and environmentally friendly?

    Yes. The active ingredient iron phosphate also occurs in nature. Even if a bird, pet, hedgehog or earthworm feeds on a pellet they will not be harmed. This is one of the main reasons why iron phosphate pellets are approved for Organic gardening. Please note that all plant protection products such as these, have to include standard safety warnings on the packaging which relates to keeping out of the reach of children and pets. This is standard good practice.

    *Use plant protection products safely. Always read the label and product information before use.

  • Can I use Sluggo® Slug and Snail Killer+* early in the season e.g. February / March?

    Yes, the efficacy of the product doesn’t depend on the temperature so once slugs and snails are active in the spring and causing damage you should begin to spread Sluggo® Slug and Snail Killer+*.

    *Use plant protection products safely. Always read the label and product information before use.

  • Can I use Sluggo® Slug and Snail Killer+* in slug and snail traps?

    No, that isn’t the best way to use the product. Sluggo® Slug and Snail Killer+* should be spread widely among plants and crops so that the slugs and snails can find the pellets while crawling around.

    *Use plant protection products safely. Always read the label and product information before use.

  • Sluggo® Slug and Snail Killer+* was not effective. I couldn´t see any dead slugs and snails or trails of slime!

    The efficacy of Sluggo® Slug and Snail Killer+* isn´t based on dehydration like metaldehyde pellets. When the slugs have eaten the pellets they burrow into the ground and die there out of sight. Therefore you will not find any trails of slime or dead snails.

    *Use plant protection products safely. Always read the label and product information before use.

  • Do I have to reapply Sluggo® Slug and Snail Killer+* immediately after rain?

    No this isn´t necessary. The pellets swell up when they get wet but don´t disintegrate and then in dry weather they return to their original shape. In fact, wet and moist Sluggo®+* pellets are even more attractive to slugs!

    *Use plant protection products safely. Always read the label and product information before use.

  • Can I use Sluggo® Slug and Snail Killer+* to protect edible crops such as lettuce and strawberries?

    Yes, just ensure it is applied early enough and spread evenly among the plants. There is no waiting time before harvesting crops.

    *Use plant protection products safely. Always read the label and product information  before use.

  • Can I reapply Sluggo® Slug and Snail Killer+* just before picking lettuce?

    Yes, it may be applied at any point in the growing cycle and you do not need to wait before harvesting lettuce.

  • Are there any plants which slugs and snails don´t like?

    Yes, here are some examples of plants that slugs do not like: verbena, ferns, lady's mantle, goldenrod, periwinkle, lavender, snapdragon, pink phlox, yarrow, geranium, thyme and lamb´s ear.

  • Is it sufficient to spread a circle of Sluggo®+* around individual plants?

    No, this will not provide full protection as when a slug or snail has eaten through this circle of pellets the ‘door is open’ for other slugs. Therefore you have to spread Sluggo®+* evenly across all areas requiring protection.

    *Use plant protection products safely. Always read the label and product information before use.

  • What can I do to prevent slugs and snails?

    Water only in the mornings and surround particularly vulnerable beds with a slug and snail barrier. Frequently break up the soil so that the slug's hiding places are destroyed. Encourage hedgehogs and other beneficial creatures with piles of brush wood which act as a mini habitat for them.

  • I have recently applied the product but can no longer see any pellets – what has happened?

    The slugs and snails have eaten them and have disappeared to die! You should reapply the product.

  • What happens to any pellets that are not eaten?

    After several weeks, depending on weather conditions, they will degrade into the ground. The good news is that as they contain iron (III) phosphate they will also provide the soil with nutrients as they break down.

  • I don't feed my lawn so that I don't have to mow it as often. However, weeds have now started spreading.

    If you don't feed your lawn at all you are weakening it. Weeds, however, are much more able to spread and crowd out the lawn grasses. With Neudorff's Organic CleanLawn it is primarily thickness that is improved rather than height which means it becomes beautifully lush without you having to mow as much.

  • Do I have to spread the fertiliser with a fertiliser spreader?

    No, that isn't really necessary though the lawn will grow more evenly using one than if you spread the fertiliser by hand.

  • Can my pet go onto the lawn again after I've fertilised with Organic CleanLawn?

    Yes, your animal can use the area again straight away. Organic CleanLawn contains no substances harmful to animals.

  • What should I do with my grass clippings?

    Large amounts of grass clippings go mouldy in the Thermal Compost Bin. To avoid this let the blades dry out a little bit beforehand and always mix dry material such as fine bark mulch with grass clippings. Don't forget to speed up the composting process with Organic Compost Accelerator.

  • Can I also use WeedFree Plus+* with very small weeds?

    Yes, it can be used on all sizes of weed. But the effect is better when the green surface area of the weed is larger so that the maximum amount of active ingredient can penetrate the leaves and reach the roots.

  • Will the Weedkiller* products also damage my shrubs?

    All Neudorff Weedkiller* products are broad-spectrum herbicides. Which means that everything that has green leaves and is touched by it will die. It is best to use a spray canopy in the perennial border which will make sure that your shrubs do not come into contact with the spray mist.

  • Can I also use WeedFree Plus+* on the lawn?

    No, because WeedFree Plus+* acts on all green plants and will therefore kill the lawn.

  • How to use a pesticide?

    Always use pesticides as instructed on the label. The label will explain how to use the product safely and what precautions you need to take. Always read the label before applying a pesticide. Ensure you follow the label instructions carefully. Where appropriate, dilute the product with water and apply it evenly. Never make up more than you will need on that day. Never over apply a pesticide – this isn’t necessary and could even damage the plant or lawn that you are treating.

    For lawn weedkillers make sure that you apply the product evenly – too much can damage or even kill the lawn! Always wash hands after applying a pesticide. Follow each step of the label!

  • Pesticide Storage

    It is a legal requirement, and for safety, to always store pesticides in their original containers. After use ensure packaging is tightly closed or sealed to avoid spillage. Store pesticides in a safe place, out of reach of children and pets. Store metaldehyde slug pellets safely to avoid accidental poisoning of children and pets – particularly dogs. It is also illegal to store pesticides that are unlabelled and not in their original container, for safety reasons.

  • Pesticide Disposal

    Do not pour pesticides down the drain. Pesticide containers that have held concentrated product should be rinsed three times adding the washings to the final spray solution. The empty container can then be placed in household waste. Ready to use product (i.e. trigger sprays) can be disposed of directly into your household waste. Pesticide containers e.g. bags and cardboard boxes can also be disposed of in your household waste. Read the label for any other advice on disposal of the product or empty container. Do not burn any pesticide packaging. Contact your local Council for advice on disposal of unwanted pesticide or empty containers. Details can be found at: www.pesticidedisposal.org or you can phone your council direct (usually the waste disposal section of your council which can be found in the phone book).