Part 28 (1/2)

FOOTNOTES:

[7] Rivers' _Rose Amateur's Guide_.

[8] See p. 57.

CHAPTER X

ROSE PESTS

THE enemies of the rose are many. They are of two cla.s.ses; the insect foes, and diseases caused by Fungi. And their prevention and destruction are tasks, as every rose-grower knows only too well, which call for ceaseless vigilance and constant work, more especially in the early months of the season. For if remedies are applied in good time, the pests of both kinds give comparatively little trouble after May and June until the early autumn, when a fresh crop of both appears.

No such powerful weapon has ever before been put in the hand of the rose-grower, as the remarkable handbook on the _Enemies of the Rose_, published this spring (1908) by the National Rose Society. For here the veriest tyro can recognize the diseases which puzzle him and the insects which drive him to despair in all stages of their mischievous existence, figured in exquisitely drawn and coloured plates; while in the terse and admirable letter-press he is told how to combat their destructive ways.

This little book can be obtained by non-members of the Society for 2_s._ 6_d._, through any member; and it ought to find a place on the shelf of every rose lover.

=Mildew=, of all Fungoid diseases, is the worst we have to contend with.

Some roses, such as the lovely _H. T. Killarney_, the _Crimson Rambler_, the _H. P. Margaret d.i.c.kson_, and others, are specially subject to this pest; and unless measures are taken against it when the very first sign appears, it quickly spreads to other roses. Two seasons ago a plant of _Margaret d.i.c.kson_ had it badly in my garden, and infected its neighbour, _Frau Karl Druschki_, to an alarming extent.

This odious disease, though more or less always present in the garden, appears generally in marked strength twice in the season--first in spring, when the foliage is just fully developed, and secondly after the midsummer shoots are grown.

It must be attacked early before it gets any hold, in fact, before it actually shows, if we have reason to suspect its presence. _Flowers of Sulphur_ is the most usual and effective preventive. It is blown over the plants with bellows made specially for the purpose. Floating like a fine cloud all over the garden it settles on every part of the plant.

The early morning before the dew is gone is the time to apply it, as the evaporation of the dew has some subtle effect on the sulphur which greatly increases its efficacy. Rev. F. Page-Roberts strongly recommends _Black Sulphur_ instead of the ordinary yellow, used with one of the ”Ideal” Powder Bellows, made by W. Wood & Son, Wood Green.

Another preventive, which is advised in the National Rose Society's handbook as extremely efficacious, is syringing with _Pota.s.sium Sulphide_, _Liver of Sulphur_--half an ounce to a gallon of water. The handbook advises adding a tablespoonful of liquid glue, or the whites of two eggs to every gallon of water, as this causes the solution to adhere better to the foliage. If thoroughly and carefully applied with a very fine syringe, such as the Abol Syringe, using the bend attached to get at the under-side of the leaves where the fungus first appears, this wash acts rapidly upon the pests.

_Mo-Effic_, a new preparation, has been highly recommended in the last two years. I have not tested it myself. But Mr. Mawley considers it most successful.

=Black Spot= is another troublesome pest. It attacks the foliage alone, and not only spoils the appearance of the leaves, but so injures them that they fall off prematurely. The disease can be best checked by spraying with the _Liver of Sulphur_ wash, beginning early in the spring and going on at intervals.

=Rose Rust= and =Rose Leaf Scorch= may also be combated with _Liver of Sulphur_ wash.

But in all these three last diseases, it is a matter of the greatest importance to collect the badly diseased leaves on the plant, and especially to pick up every one lying on the ground, and to see that they are burnt at once and not thrown on the rubbish heap, where they will only infect the soil.

=Sooty Mould=, the unsightly black stuff which often covers the foliage, is a parasitic fungus not upon the leaf itself but upon the ”honey dew”

deposited by Green Fly. If therefore the honey dew is kept off by destroying the Aphides which secrete it, _Sooty Mould_ will not appear.

INSECT PESTS.

=Green Fly=, or =Rose Aphis=, is alas! too well known in every garden to need much description. But the reason why it is so difficult sometimes to get rid of this pest is not so commonly known. The Aphides breathe through pores at the sides of their bodies. And in order to kill them, some substance must be used which will close these pores. Therefore syringing with water or any clear liquid is absolutely useless; for if a few Green Fly are knocked off one shoot they will only settle on some other. We often hear people say after a thunderstorm, ”This will clean the roses and wash off the Green Fly nicely.” Far from it. They only increase the faster; while the caterpillars rejoice, and flaunt themselves openly on every bush. Then in despair some one uses paraffin or some violently caustic wash for spraying the Green Fly, and destroys his roses thereby.

Nature has mercifully provided some enemies to prey on the Green Fly--and these help in some small degree to keep the pest down. The chief of these is the Ladybird, which both in its adult and in its larval state devours them ceaselessly. The pretty green Lace-wing Fly or Aphis Lion is also useful, as its larvae are provided with ”large sickle-shaped jaws for picking the Green Fly off the plants.”

The Hover Fly--which looks like a small, slim two-winged bee or wasp--lays its eggs in the thick of a ma.s.s of Green Fly, and its green and grey leech-like maggots feed upon them. And the Ichneumon and Chalcid Flies lay their eggs in the bodies of the Aphides and their maggots feed on them from within.

But all these are of comparatively little help to the unhappy rosarian, who must therefore devise unnatural means to clear his plants.