A Note on 
The Cultivation of Irises 
The Iris is a boon for an immense region where other flowers cannot grow. They 
are the best drought resisters we have. 
A long experience in replying to queries received from beginners in Iris culture 
enables me to deal, in the following notes, with most of the details of cultivating 
Irises regarding which beginners are often in doubt, or are, unfortunately, misled 
when taking advice from those who are not competent to give it. My notes apply 
particularly to the April-flowering and May-flowering Bearded Irises—the finest of all. 
Iris grow easier and multiply faster than any other perennial. Plant them in a 
sunny location that has a good drainage. Iris are easy to cultivate and can be planted 
almost any time the ground is not frozen. Do not plant too deep. Plant so that the 
rhizome is just below the surface. Spread out the roots and water the hole. Then 
draw the earth around the rhizome and firm well. If the soil is heavy and the drain- 
age poor a raised bed and application of hydrated lime is advisable. Never use manure 
or leaves as they are likely to cause rot. Varieties that increase rapidly should he 
divided and reset every third year. Iris seem to succeed over a greater range of ter- 
ritory than any other plant, withstanding the cold of Canada and the heat of Mexico. 
A light covering of straw put over the tender Iris after the ground freezes will help 
to carry your plants safely through the winter. Good bloom the following spring may 
be expected from well-matured plants which make a reasonable growth in the fall. 
Irises are subject to very few diseases when grown under normal conditions, and 
only one of these—Iris Rhizome Rot (Pseudomonas Iridis)—is serious. This is a bac- 
terial disease, and usually attacks the plant in early summer at the base of the stem, 
which collapses. The rhizome becomes slimy and rotten. Affected plants should be 
lifted immediately, the diseased portions of the rhizomes cut away and dusted with 
sulphur, powdered gypsum or plaster of paris. After the treatment the plants may be 
dried off for a few days and then replanted. Iris Leaf Spot (Heterosporium Gracile) 
is sometimes prevalent, and is caused by the attack of a fungus. It is recognized by 
the development of pale round spots on the leaves, which often spread rapidly until 
the whole surface is covered. The leaf dies, and the plants are consequently weak- 
ened. This disease is seldom troublesome on ground which has plenty of lime, and 
the best remedy is prevention—by giving the ground a good dressing of lime in the 
autumn. Badly diseased leaves should be removed and burnt. Iris Leaf Rust (Puccinia 
Iridis) is more uncommon and appears as small reddish rusty spots on the leaves, 
spreading rapidly. The remedy is spraying with a solution of potassium sulphide 
(liver of sulphur), one ounce dissolved in a gallon of water, every three days. 
Another disease which occasionally makes its appearance is the so-called “fire” or 
“scorch,” the plants when attacked appearing as if they had been burnt. This trouble 
starts in the tips of the leaves and works down, the whole plant eventually becoming 
brown, and the roots withering and dying. Little or nothing is known as to the cause 
of this disease or its cure and it is under investigation at the present time. It is 
seldom very serious for as a rule only isolated plants are attacked, and it usually 
appears after a period of drought. A suggested remedy is to lift the plants and hang 
up by the roots to dry out in a hot, sunny place. After some weeks the rhizome 
usually recovers and starts to make fresh growth, when it can be replanted. 
Borers seem to be important things that one has to contend with. Watch the 
foliage, beginning the first of June, and where you see a leaf that looks slimy or the 
edge notched, look out for the borer. With the aid of an old glove squeeze the leaf 
up and down between the thumb and finger. Slugs are often troublesome and do much 
harm by eating out the young eyes of the rhizome. Soil in which their presence 1S 
known should be dressed with plenty of sulphur. 
and finally, remember 
That my experience is always and in every way at your service. 
