Having tried a lot of homemade pest control remedies, I'm thinking of using pesticides for a change but im not so sure on how to use it correctly. The label says to use 25ml per liter of water but nothing else and i was wondering if there's such a thing as "the best/worst time to apply it" so if anyone has tried this stuff, let me know on how to go about it.

  • Who uses pesticides, I call the ecological imbalancers? Commented Apr 3, 2019 at 21:36
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    I think you should write some more about the specific pesticide, e.g. is it against which pest. Commented Apr 4, 2019 at 7:39
  • @black thumb_ well i certainly dont plan on using it through out the year. I only plan on using a little now to kill a very small number of aphids untill all the beneficial incests have woken up. If i wait and do nothing, those things will have multiplied by the hundreds and no predator would be able to fight them off then. Commented Apr 5, 2019 at 9:49
  • you're hurting the predators :'( Commented Apr 5, 2019 at 18:39

2 Answers 2


Insecticides are best applied during the day (when you can see what you're doing), but preferably when the plant is not in direct sunlight, and preferably at dusk, when the bees and other pollinating insects have stopped working, although that is more important when plants are actually flowering - if they're not, you're less likely to spray any beneficial insects because they won't be there. Always spray beneath the leaves as well as the tops, and spray till run off... and avoid spraying flowers if possible. You don't say what type of insecticide you're using, but note that systemic insecticides work for up to two weeks, contact insecticides only kill what's on the plant when you spray, they confer no protection after that. If the container doesn't say what type it is, the recommendations for how often to apply will demonstrate which one it is - systemics usually say apply every 10-14 days (if necessary) or similar.

  • But why not at night though? I mean during the day, if i spray it on, it's gonna get the beneficial incests too but at night the beneficial incests fly away returning to their homes while the unwanted critters stay behind sticking themselves onto the plant. So a night time application would kill them on contact without harming any of the beneficial incests or atleast that's what makes sense to me but of course i could be very wrong. Commented Apr 3, 2019 at 20:39
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    Oh, yes, there's a bit I missed out, I'll adjust my answer.... half asleep today!
    – Bamboo
    Commented Apr 3, 2019 at 21:23
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    Have you identified the insects you're trying to kill so that you know that you're actually killing pests? I knew someone who treated roses and annual geraniums with a neonicitinoid (systemic) insecticide to kill Japanese beetles. She identified the insect properly, but by the time the beetles were eating the rose flowers they had already mated and it was really too late to do anything about next year's beetles. To make matters worse, the beetles never touch annual geraniums. Because she was using a systemic neonic, she was actually killing bees, flies, and butterflies with her poison.
    – Jurp
    Commented Apr 3, 2019 at 23:59
  • @bamboo_ that's good information. Thanks and regarding the kind of insecticide, well i checked and the label reads "general purpose home garden insecticide" and it also says to apply after 10-15 days if necessary so i guess it's a systemic one but what about contact insecticides. Are we talking like those common household fly/roach sprays? You can use that on plants? Commented Apr 5, 2019 at 9:23
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    No - they're not formulated to be used on plants, Most countries have a choice of insecticides (contact,systemic, maybe different ingredients) and they are specifically formulated for use on plants.
    – Bamboo
    Commented Apr 5, 2019 at 9:38

It depends on the insecticide.

First rule: read the label, but in your case you have no restrictions. Some insecticides should not be used when too hot, but some other not when it is too cold.

Second rule: if it is a contact insecticide (not for night pest), better to do in the early morning, when insects will sleep or not move much. I think night is also good.

Then you should check what pest you are fighting. From your comment on @Bamboo answer, it seems that you are thinking that good insect are active only during the day. This is not true (there are various flowers [especially white or very pale] which are pollinated only during night, not frequent on gardens, because you do not want flowers that you never see). But also some pests works only during day. Caterpillars often eat during night and hide during day. On the other hand we like many butterflies (but not moth, which are nocturnal).

Many insecticides do no arm bees (but some yes), so I would also check not to spray them when you see bees.

But weather is also important, you do not want to spray too early, if there will be dew in the morning. On the other hand, if you have less wind during night, night will be ideal (compared windy mornings or evenings, but depends on your locale climate).

Personally, I think day is better, because you can check better what to do, and so being more effective (all surfaces, and more regularly). On the other hand, you may use them also on night.

If it is very hot, night is better, on contact insecticides: you need to spray all surface, so very tiny drops, but they could evaporate before touching leaves. On agriculture, there are many studies about size of drops, speed of spraying and effectiveness (all depending on culture, pesticide, and climate), but this is mostly for professionals.

  • _ very helpful. Thanks for the info. I read the label and it reads "general purpose home garden insecticide". However my problem is just with aphids. They're only a few. Enough to easily remove by hand but since buds are forming at this stage, i won't get all the aphids without knocking off a lot of the new growth. You mentioned night time pollinators and i got curious so i grabed my torch to examine my plants and saw quite a few house flys but much bigger in size resting on the leaves here and there. Where do they fall, pests or pollinators? Commented Apr 5, 2019 at 9:56
  • Also, i took notice of the current weather conditions as you pointed out and saw best to spray in the evening. Hope i wouldn't need to spray a second time. Commented Apr 5, 2019 at 9:56
  • @HamidSabir: Maybe you should ask a new question with the photo of aphids. Sometime just water or easy remedies are useful (but it depends on the type) Commented Apr 5, 2019 at 13:36

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