I don’t know if it was the mild winter we had, the dry spring afterwards or some other factor, but this year I seem to have a problem with whitefly (Aleyrodes Brassicae). They are a small white fly (original name huh?) a millimetre or two long and they love to get together and party on the underside of broccoli, cauliflower, kale etc. leaves.
I noticed a few earlier in the season but they seem to have had a population explosion over Christmas. It is pretty hot and dry here at the moment and while I do remember the Permaculture principle “Observe and Interact” the only interacting and observing I did over Christmas was with my family. Oops! So now I come back to what can best be described as an “infestation” and have no idea what to do about it, research time!
After some research I know understand the little buggers a bit better but the control measures leave a bit to be desired –
- A healthy soil – this gives you health plants, but by and large my soil is in pretty good condition well fed, well mulched and reasonably well watered. (well it was Christmas!)
- Feed the plants correctly – too much nitrogen gives large sappy leaves that the bugs love, but this was not an issue for me either.
- Cultural control – remove the winter brassicas as soon as they have cropped to prevent build-up of the pest. It was a bit late for that, but I grow brassicas year round here and it hasn’t been a problem until now.
- Hand picking – pick the little blighter off the plants one at a time by hand………really? There are millions of the buggers, they are tiny and my patience doesn’t stretch that far. This one is possible at the start of the season maybe, if you think there might be a problem.
- Use the hose – They can be blown off the plants by a good, solid spray from the hose. Tried that and while it does work they just lift off in a cloud and then re-settle once the spray stops… ……..good thinking 99! Although having said that it does seem to crap them off some and soften them up for later treatments.
- Encourage predators – we let a number of veggies go to seed, including brassicas like broccoli to attract parasite wasps etc. but in this case the infestation had gotten away from both them and me!
- As a last resort a spray of some description – I am betting either a pyrethrum spray of some description of the old standby chilli and garlic spray would work.
But is there no better way? After some thought and watching them lift off in clouds every time I harvested something in the area, I had a brainwave – why not use the vacuum cleaner. Yup, that idea sucked!
In the best of all possible worlds I would have gone for a small and portable “Dustbuster” style hand vacuum but we don’t own one. We do own an Electrolux “Green” vacuum cleaner (there is a leaf on the label, it MUST be environmentally friendly!).
After rolling out the cord and connecting up I started it up with just the metal end of the hose (that is, no attachments) but while it was effective in sucking the little critters down it also had a habit of sucking down the leaves as well, bad idea! After a quick troll through the attachments I found a brush that was basically a ring of bristles around the vacuum nozzle. It worked! I could brush the back of the leaves and it would remove and suck down the whitefly without doing nasty things to the leaves.
It was a bit tedious and I would not want to try this stunt on three acres of cabbages but it really did work. Obviously it would work better if you caught the infestation earlier and had less pests to deal with but it is a great non-chemical way of dealing with this pest. Also, spreading the task out a bit by taking several goes at it makes it easier than trying to suck them all up in one go.
One final thought – If you are growing your own food your neighbours probably already think you’re a weirdo, if they see you out vacuuming your broccoli it may just confirm their suspicions. I suppose you could just tell them that you are tarting up your plants for a show, in the same way as people brush and clip their dog before a pet show. In my case they all know I’m a weirdo so I just don’t care!
