Using Insecticide on Dahlias

It is also an advantage to apply a deep mulch to the ground, if the material is available. A great many growers do not incorporate any manure in the ground at digging, preferring to reserve all.

Cow manure is excellent. It is probably best to mix a certain amount of straw with this as it is rather heavy and cold, and might on these accounts be slightly deleterious on a heavy clay soil in a wet, cold summer if applied unmixed. Compost is also good, preferably reasonably well broken down before application.

For applying insecticides in spray form the small hand pressure sprays are hard to beat if only a comparatively few plants are grown, as they are easy to use and most economical. For greater numbers of plants, the stirrup pump type of spray is quite effective, though perhaps a little heavy on insecticide, or there are quite large pressure sprays available which are really excellent. They are rather expensive as an initial outlay, but this is offset by the saving in the quantity of insecticide used and the comparative ease of application.

In addition a good deep mulch will tend to smother weed growth, because even strong growing weeds require light immediately after germination from seed, and this requirement is automatically denied them. The exceptions that manage to thrust their way through the mulch are generally suffering from the effects of etiolation and are spindly, puny caricatures of their normal selves.

Straw makes an extremely good substitute. It is cheap, clean and very springy, and it is most effective in preventing the ground compacting under pressure. It is an excellent practice to put an additional layer of loose straw along the pathways for this one reason.

From this stage onwards it is better to keep the weeds down by hand pulling. The wisdom of providing wider pathways every other row will be easily seen, otherwise the whole of the dahlia plot would become hard trodden.