Get rid of grubs without harming bees
As daylight hours increase and plants start to grow, problems can become apparent in lawns.
During autumn, grass grubs were chowing down on grassroots prior to pupating.
It means when the grass tries to come away, the roots are insufficient to sustain growth and it dies.
It’s too late to do anything about this now. The time to treat the lawn for grass grubs is in the autumn. when the rain has moistened up the soil and the grubs are feeding near the surface. so they are easier to access and kill. In spring, the damage has been done and the grubs have gone.
However, in a few weeks or a month the cycle will start over. Invading grass grub beetles will mate and feed on garden plants before laying eggs deep in the soil of the lawn, hatching out as white grassroot chewing grubs.
Killing lots of the beetles when they arrive will greatly reduce the damage to gardens and lawns over the next 12 months.
As soon as holes start appearing in the foliage of roses, citrus or other plants with no noticeable culprits, it’s likely they are caused by feeding beetles. A torch in the early evening will reveal the critters having a munch up.
To counter this, make up a spray of Wallys Super Neem Tree Oil at 5mls per litre of water, add 1ml of Key Pyrethrum and 1ml of Raingard to each litre, and unless it is raining, nightly spray the feeding beetles.
The pyrethrum will knock them down quickly and the Neem Oil will stop them feeding.
Another tactic is to use a light trap. Directly under a window, onethird fill a wallpaper trough with water and add a little kerosene.
At dusk, turn on a bright light behind the pane for about 2 - 3 hours. Attracted by this light, the beetles will hit the window and fall into the trough. The kerosene prevents their escape for easy disposal next day.
The worst affected lawn areas are usually where there are night lights or street lights. These attract the beetles to the area, and they lay their eggs nearby.
For a really great lawn, apply Wallys Neem Tree powder (available in 3kg bags) to a test area after the grass has been cut, and lightly water to settle the powder into the soil. A lawn roller can be used to press in the powder, which also treats grassroot nematodes.
If, after a few weeks there is an improvement in this test area, treat the rest of the lawn for nematodes.
Another product is 3 in 1 for lawns which is a combination of eucalyptus and tea tree oils along with a natural food and a wetting agent. The 1 litre concentrate is watered down at 1: 25 and applied to 50 sqm of lawn which is then further watered to take it deeper into the soil. It’s safe to use and it takes out all the lawn pests.
Best applied after mowing the lawn and because its washed into the soil and is not systemic it will do its job without harm to pollinating bees
Porina caterpillars are another lawn pest that feeds at the base of grass stems causing bare patches. Porina will also chew through the stems of young garden seedlings.
To control these, mow the lawn and make up Wallys Super Neem Tree Oil at 5mls per litre with 1ml of Raingard, and either spray or use a Lawnboy.
When the grubs emerge from their tunnels at night, the Neem will stop them eating and they’ll starve to death over a week or so.
Badly affected areas need a treatment about every 3 months.
Prior to any treatment, cut a square in the lawn with a spade, lift the turf and see if there are any grass grubs in that square and how many.
If there are 2 or 3 grubs it is hardly worthwhile treating as they will not do too much damage where on the other hand if there are a number of the grubs then its worthwhile treating.
It also pays to lift some turf in different areas as you may have a big infestation in one part of the lawn and hardy any in other parts which means why waste your money treating the whole lawn.
The likely parts that will have the worst number of grubs is where there is night lights or street lights nearby as the beetles are attracted to the lights at night then lay their eggs nearby.
Also areas where there is a history of a problem will also be a good place to check as the beetles will return to where they emerged from if not attracted away at night by lights.
What treatment to use? You want to use a treatment which is going to be safe for children and pets to still use the lawn without harming them. Also you do not want to use a treatment that will harm bees or bumble bees weeks or months later if there are any weeds or clovers in the lawn that are going to flower later.
Chemicals in the family of Neonicotinoids are extremely harmful to honey bees and bumble bees these include chemicals from the family such as imidacloprid (found in the brand name Confidor also).
Problems ring me at 357 0606 Email email@example.com Website gardenews.co.nz
Grass grub beetles will soon be chewing holes in garden foliage. They then lay eggs in the soil, and the larvae set about destroying patches of lawn.