Plant Doctor Archive

Using chemicals in the garden

How can I safely use and store chemicals that are to be used in the garden?

If you decide there's no other way, then you've got to know how to use them and store them properly.

There's a wide variety of chemicals available to kill insects, mites, fungi, bacteria and weeds. All they've got in common is they kill living organisms, so it pays to take some precautions.

Rule number one is to protect yourself. Hat, good idea. If you've got some goggles, even better. Gloves, of course. Cover your arms and your legs — don't spray in your togs!

Number two, always read the instructions on the pack. Every pack of every chemical you buy has instructions on how to mix them, how to use them, how many millilitres per litre. Don't go using some more just for good measure, because it won't work. It's as simple as that.

For the mixing, that's a job in itself. Mixing's got to be done very carefully. The first thing you do is put most of the water you're mixing into already in your sprayer.

What I do is use 50 ml of say moss killer per litre of water. I've got a lovely measuring device. I pour 50 ml very carefully, no more, no less. The idea is to get this into the water and mix it up thoroughly.

When you finally do go and spray, don't do it on a windy day, because the wind will drift all the spray particles everywhere except the place where you want it to go. There's a chance the spray particles will come to your face.

Don't use agricultural chemicals because they are usually a lot stronger and often require specialised equipment.

When you're spraying your veggie garden and food crops, take a note of the withholding period stated on the back of the pack. It is the period you need to leave the plants alone, between your last date of spray and the date you can safely harvest them. If you don't know, or if you're not sure, go to your garden centre and ask them.

Storing chemicals is important too. They need a clean, dark, cool and dry place. It is important to store chemicals in the original container with the lid tightly on, and off the ground. Don't put stuff into old drink bottles, either. Others might get their hands on it, especially little ones, and not know what it is.

Keep your chemicals in cool conditions. Hot conditions can make them vaporise and the fumes can make you quite sick. Never store pool chemicals, like chlorine, next to oily substances, such as lawnmower petrol. If they accidentally mix, they can cause a fire. Failing a fire, they'll at least create some really toxic fumes.

Buying chemicals is easy. Getting rid of them is not so easy. Contact your local regional or city council and enquire whether they've got a collection policy.

In Auckland, the regional council, from time to time, collects hazardous or toxic waste free of charge, so check in your local district if the same thing applies there.

Advice by Dr Dan Blanchon from Unitec's Diploma in Sustainable Horticulture and Bachelor of Resource Management.

Reproduced with permission from NZOOM Home and Garden content, from the previous website of  The views expressed here are not necessarily those of the RNZIH   HOME AND GARDEN   Plant Doctor Archives Main Page