Garden pest control with Wally Richards
The met service has reported that we had the warmest August ever since records began with about 1.5 degrees above average, which does not seem a much on those odd cold days, but for a lot of insect pests it means an early arrival.
I was surprised to find the first leaf hopper in my garden the other day along with a small number of whitefly. A couple of gardeners from other parts of New Zealand informed that they had already seen the odd white butterfly flitting around their cabbages.
This means that the early emergence of pest insects bodes problems in the weeks ahead, as it does not take long before eggs are laid and grubs are into our gardens.
If we take the time to knock out these early invaders we will reduce the size of the problem that will happen over the next few months.
So strike now and repeat your control methods before the situation becomes a real problem.
Insect pests will attack their host plants which often include weeds and ornamental plants in your garden so for good control of any of the pests, sprays need to be applied to all plants and weeds.
If you are a diligent gardener then the removal of all weeds will greatly reduce the amount of plants you need to spray, if not so careful, then you will need to cover the weeds as well.
A second problem arises for many gardeners who keep a good eye on the pests in their gardens and use sprays to irradiate them, before they become a real problem and that is from over the fence.
Houses that surround you, owned by people that are not keen gardeners, are very often breeding grounds for a whole range of pests which will keep on jumping over the fence into your gardens.
This is a difficult problem and unless the neighbours keep the pest populations under control on their section you will spend the whole of summer and autumn trying to control the invaders.
If you are on friendly terms with your non-gardening neighbours then you could explain the problem to them and ask if they would mind you popping over every now and then to spray their gardens and weeds.
If this arrangement cannot be made then you are going to spend about three times the amount of time and spray to protect your own plants, than you would have to do otherwise.
A good natural general spray that you can use at this time would be Neem Tree Oil with Key Pyrethrum added. Firstly place your bottle of Neem Tree Oil into a jug of boiling water for about 10 minutes to ensure that the oil it is nice and liquid, then measure out 10 mls for each litre of water you intend to make up.
Use non-chlorinated water for this so it will not harm the microbes on the foliage of the plants you spray. (Microbes/bacteria on the foliage protect the plant from the nasties so you do not want to harm them) You can simply remove the chlorine from water by placing an air stone into the water attached to an air pump (as used in fish tanks) and allow it to bubble away for a few hours.
If you have a good filter on your indoor tap that removes chlorine (10 micron or less, carbon bonded filter) then use that water.
The water should be warmed before adding the Neem Tree Oil as this will help it mix better and less chance of blocking spray jets and filters.
Add to the mix 1 to 5 mls of Key Pyrethrum for every one litre of spray and then agitate to obtain a good overall mix.
Spray just before dusk so that the pyrethrum is not affected by UV till the next day, which means its active all night.
Key Pyrethrum is a fast knock down spray that affects the nervous system of insects.
The Neem Oil is an anti-feedent and growth regulator which means its not a fast knock down but causes the pest’s death by them not being able to eat or alternatively grow.
There are three brand name Neem Oil products in New Zealand, two of which are not registered in NZ with NZFSA for use on food crops and a very expensive one which is and also certified organic.
In Australia Neem Oil (one brand anyway) is also certified for Organic Growers.
It can be an expensive exercise to obtain certification and the reason the other two Neem Oils are not.
Recently a gardener/green keeper showed me an article which said that the reason for Neem Oil not being certified for food crops was because of possible carcinogenic aspects.
In the same article which was to do with the potato pysllid it was stated that Orthene would be a good chemical to use against the pest but said that Orthene was no longer available but was included in Yates’s Shield still.
Now Orthene is a known and proven carcinogenic so the writer certainly has not done any proper research and has a biased article in favour of his sponsor.
If you have a Neem Oil that is not registered for food crops then it would be your discretion whether to use it or even Shield for that matter. (Shield is only registered for use on Roses and Ornamentals and has a least one chemical in it, which has real health concerns)
Anyway back to the suggested spray of Neem Oil and Key Pyrethrum, this can be used as a preventive to stop population build ups of pest insects on either a weekly, 2 weekly or monthly program dependant on the need. Spray just before dusk for best results and check all plants in your garden at least once a week for any sign of insect pests.
Another concern at this time is the pollination of fruit trees and fruiting plants because of the lack of honey bees these days.
There are pollinating insects around such as bumble bees and native bees which have not been affected by the viroa mite; the problem is to entice these pollinators to your fruiting plants when they are in flower.
My suggestion is to dissolve raw sugar in hot water and when cooler, spray the sugary syrup over the foliage of the fruit trees late in the day, when the pollination has finished for the day.
This mix may do the trick in getting a better fruit set.
Do not use honey as this is frowned on by bee keepers in case of the spread of any virus.
If there are honey bees still around in your area then they maybe attracted by the sugar also and they are still the best known pollinators going.
Any questions please ask in the comments box below.