sciarid flies killing my seedlings?!

[John Walker]

Biological controls are one of the more benign and extremely useful spin-offs from commercial horticulture that have proven to be of consistent value to gardeners everywhere. No one should be misled into thinking they are only of use to commercial growers (although of course they also use them to great effect).

As if evidence were needed, Harrod Horticultural have recently published the second edition of their 'Little Book of Least Wanted Pests'. This 24-page, comprehensive booklet covers all the main pests, including aphids, caterpillars, carrot and slugs and snails, and explains the natural biological (i.e. non-chemical) controls available to deal with them.

In this edition there is also information on organic 'plant strengtheners' based on natural beneficial fungi and other bio-stimulants. It's interesting reading even if you don't have a pest in sight.

You can request a paper copy on this page:
http://www.harrodhorticultural.com/Harr ... PL-093.htm

Or download a PDF version here:
http://www.harrodhorticultural.com/PUBL ... fPests.pdf

They also offer a free pest advice service by email.

There's nothing impractical about treating sciarid fly with biological control, especially if using nematodes. You simply mix the nematodes with water and apply them to your pots (you can't 'overdose' when using these treatments). £6.95 looks pretty good value as you probably won't need to use them all in one go and what's left can be stored for several weeks in the fridge. Sciarid flies often hop from houseplants to other plants, including those in a greenhouse, so a preventative treatment at this time of year can be quite a useful move.