0Controlling pests on indoor plants

I grow toma­tos, cucum­bers, chil­lis, lem­ons and olives in a south facing con­ser­vat­ory.  Over the last 5 years I’ve suffered with a range of ver­min attack­ing my plants, it seems to be a dif­fer­ent type of pest each year after I’ve conquered the pre­vi­ous pest.  Below I cov­er a few suc­cess­ful ways I’ve found to con­trol a range of pests.

General advice

I’ve found that some vari­et­ies of each type of plant are much more res­ist­ant to ver­min than oth­ers.  For example the F1 Aji Limon chilli pep­pers don’t seem to be tar­geted much by any ver­min, so I now tend to grow these rather than oth­er chil­lis.  If all else fails then I recom­mend look­ing at the vari­et­ies you are grow­ing and try some dif­fer­ent ones.

Red spider mite

Red spider mites are one of the worst pests as they seem very dif­fi­cult to des­troy.  They are fairly res­ist­ant to most sprays and treat­ments.  I have found a few approaches effect­ive.  The first is to grow a few pots of chives both inside the room, and in the garden.  Red spider mites appar­ently are repelled by the smell of chives.  The second con­trol I have used is pred­at­ory mites that eat red spider mite.  Red spider mites also like a room to be dry and hot so I have allowed the room to get colder at night (e.g. by leav­ing a small win­dow open).

Greenfly & Blackfly

Green­fly and black­fly are com­mon pests that can attack most plants and mul­tiply extremely quickly.  How­ever they are real­tively easy to kill.  Mild soapy sprays eas­ily kill them off, but to avoid using even this I usu­ally obtain some lady­bird and lacewing lar­vae around April-May and these will eat through green­fly in short order.  Green­fly and black­fly also don’t like dir­ect sun so I have replaced my drain­age trays with light col­oured ones and repainted the room to a light­er shade so that more reflec­ted light hits the under­side of the leaves.

Thrips

Thrips are also eaten by lady­bird and lacewing lar­vae so the same treat­ment for green­fly and black­fly seems to help keep thrips under con­trol.  Keep­ing a win­dow open also allows the adult lady­birds and lacewings to escape into the garden where they will hope­fully help to increase to loc­al out­door pop­u­la­tion, which in turn should reduce the sup­ply of new pests in future years.

Mealybugs

I’ve had these on my lem­on tree but not on any­thing else.  They are par­tic­u­larly fast at repro­du­cing, and seem to attack the form­ing fruit, killing it off.  They can be dealt with by a range of bio­lo­gic­al con­trols includ­ing lady­birds and lacewings.

Scale

This year I’ve had scale insects on my olive plant.  As with all pests I have ini­tially treated them by pick­ing them off and squash­ing them.  There are 3 vari­et­ies of para­sit­ic wasp (Meta­phy­cus hel­vol­us, Meta­phy­cus bart­letti, and Scu­tel­lista cyanea which are all harm­less to humans) that will con­trol scale insects.  The first 2 of the 3 are only suit­able for indoors, whilst the 3^rd does­n’t seem to be widely avail­able.  They are most effect­ive with soft scale insects.  Hard scale insects are best addressed with a type of lady­bird — Chilo­cor­us nigritus.

General advice

The large major­ity of pests seem to be sus­cept­ible to lady­birds, lacewings, and pred­at­ory wasps.  The best thing for your garden is to sup­port nat­ur­al pop­u­la­tions of these help­ful insects by provid­ing them with access to a suit­able hab­it­at and water.

What next?

I’m anti­cip­at­ing yet anoth­er new pest next year, per­haps I’ll get some vine wevils on my out­door grape vine.  Whatever comes I’ll be ready.

Got some thoughts of your own? Indulge yourself below by commenting! If you would like to subscribe please use the subscribe link on the menu at the top right. You can also share this with your friends by using the social links below. Cheers.