What Are The Essential Features of Growing Good Garden Plants? It is true healthy garden plants always keep your garden more beautiful and charming.
I suggest these features are essential.
1 . Robust growth.
2. Floriferousness and beauty o f bloom.
3. Long life.
4. No fads.
Does the tall Bearded Iris qualify for inclusion among this select company? I think so. It is very easily grown, needing little attention once planted, it is very long-lived and is generally healthy and ‘vigorous, and its lovely flowers are pro
duced with prodigal freedom.
It is, moreover, handsome in leaf as ¦well as in bloom, the sword-like foliage contrasting well with that of other garden plants.But although it is a very good-tempered plant, to get the best out o f it one should remember that it is a sun-lover and that it dislikes damp situations, so it should be planted in a sunny border in well-drained soil. It will make do with heavy clay, but not perhaps very willingly, and it is only fair to give it a helping hand by digging in sand, compost or old horse-manure to open up so glutinous a medium.
There are some kinds o f loam which with little or 110 preparation grow Irises to perfection, but unless one is fortunate enough to garden on such soil, it will be as well to treat the plant kindly and to dig in leaf mould, spent hops (if obtainable), compost or old horse-manure. Lime, once considered vital, is not now recommended except for the most acid soils, and i f it must be applied, powdered limestone or old mortar rubble (again i f obtainable) is preferable to the fiercer, slaked lime. Although the Iris is not so greedy a feeder as, say, the Hybrid Tea Rose, it has a healthy appetite, and established plantings benefit by top- dressings o f superphosphate or a general fertilizer given twice a year, in spring when growth is active, and again in early September.
A handful to the square yard scattered round, not on, the plants should suffice, and the dressings should be lightly hoed in. The autumn application could, with benefit, contain sulphate of potash, indeed a further winter dressing o f potash should be given i f it is known that the soil is deficient in that element When planting, never bury the rhizome—the woody rootstock from which the leaves ascend and the roots descend. This should be left level with the surface o f the soil, with the roots well spread out underneath.
Some gardeners excavate two holes, leaving a ridge between them, set the rhizome on the ridge, arrange
the roots on each side, fill up with soil and firm well. It is perhaps more simple to use a trowel and make only one hole, and, so long as the roots are not bundled up higgledy-piggledy and the plant is well and solidly planted, it should go ahead. Never leave the rhizomes loose, or winds will rock them and frosts heave them, and they will pine and fade away. Planting may be done at any period of the year, but the most favourable times are in September, or immediately after flowering.
I f it is merely a case o f transplanting in the same garden and the job is done expeditiously, no harm can come from an early shift, but I prefer to move Irises in September when they have made good root growth, and I find when moved at tliis time that they flower better the next year. If die plants are being given to a friend, do not lift them until early autumn. It is hardly possible to keep roots moist during a journey through the post, and I
have found again and again that Irises moved out o f the garden in June seldom flower well in the following season.
Plant in irregularly shaped blocks containing one kind, widi the rhizomes nine inches to a foot apart. After three or four years, depending on the vigour o f the variety, Irises become congested, the rhizomes creeping about in different directions, colliding and even climbing over each other, and it is necessary to lift the clumps and divide them. Do this in September, pull the clumps to pieces and replant only the healthy rhizomes, i.e. those from the outside of the clump: those in the centre will be either dead or moribund. Before replanting the pieces, which may be single or double rhizomes, re-make the soil, as the Irises will have taken most of the goodness out of it, and starved Irises naturally cannot produce such fine flowers as well-fed, contented ones.
The Iris is a shallow- rooting plant, so fertilizers and manure should be well mixed with the top spit,
not buried deep down out of reach.Once an Iris has been planted it requires litde attention beyond removal of
dead flowers, which in a wet season may spoil unfolding buds, cutting down flowering stems flush with die rhizome after the bloom is over, and a general clean-up in late autumn or the early part of die year, when dead leaves should be pulled off and burned.
Some growers cut the leaves down to about six inches from the ground in autumn and this practice helps towards the destruction of spores o f the leaf-spot disease, assuming, of course, that the primings are burned. Staking the flower stems should not be necessary except with a few o f the tallest kinds or in wind-swept positions, so plant your Irises in a sheltered place and avoid the laborious tasks o f staking and tying.
Before passing to something more pleasant, mention must be made o f diseases. The three that most commonly afflict tall Bearded Irises are rhizome rot, scorch and leaf-spot, and only scorch is deadly. Fortunately this is not usually troublesome. It is easily recognized as the leaves o f a sick plant turn russety-brown and look exactly as though they have been too near a fire. Very occasionally, i f the disease is noticed at an early stage, the life o f a plant (or rather part of it) may be saved by lifting, cutting away all affected rhizomes and replanting the ap
parently healthy ones, but almost always all the rhizomes of a clump perish. I f the plant is an expensive one it may be worth while to cut off all the hollow, dead roots and to re-set it in some out-of-the-way comer in the hope that it
will recover, but recovery is a slow process and often the patient will suffer a relapse. It is on the whole best to be philosophical and to destroy all scorched plants.
Rhizome rot, or soft rot, often attacks plants in spring, and sometimes an unhealthy appearance o f the leaves will denote it presence. It almost always attacks the rhizome at the base o f the fan o f leaves, and to defeat it one must scrape away all the soft, rotten mush until firm white tissue is reached. Some growers wash the cut surface with a solution of Lysol but, generally, exposure to light and air will harden the wound, and the plant, beyond losing its flower stem for the season, will be none the worse.
A few Irises are prone to this disease and experience will show up these culprits, some o f which are as beautiful as they are unhealthy. Leaf-spot, except perhaps in the south-west o f England, is almost negligible, and although it is with us most years, it does not appear to harm the plants. It shows in summer or early autumn as brownish spots on the leaves; these gradually grow larger and, in bad attacks, kill the foliage. Diseased leaves should be removed in autumn and burned.
The modem race o f tall Bearded Irises can be said to have been bom when the large flowered species I. mesopotamica and I. trojana were imported and used in breeding. Before that happened, all our Irises were descendants o f the smaller- flowered I. pallida and I . variegata, and they were in consequence themselves
small-flowered. Although breeders, by using I. mesopotamica and I. trojana, ob
tained tall-stemmed plants with large flowers, many of the seedlings were
tender and not too easy to grow. B y combining these new kinds with the older,
tougher Irises, the bogey o f tenderness was conquered and our present-day plants
are, with a few exceptions, completely hardy.
French and British raisers were the first to assist in the transformation, and two British Irises, Dominion, raised
by Bliss, and W. R . Dykes, raised (but never seen) by Dykes have had a great deal to do with the making o f the modem Iris. The variety W. R . Dykes figures in the pedigrees o f the majority o f our new yellow Irises.
More immediately attractive are the new “ pinks” which range from pale pink, through salmon to peach- and apricot-orange, with a side-line o f raspberry (actually light rosy-purple), decorated and lit up with startling vermilion beards.
These attract the novice as well as the connoisseur and, although the tints o f most are delicate, they show up well in the garden. Blues, from which all trace of red has gradually been banished and which are almost true blue, have already arrived, and very handsome they are, while another new colour, citron-yellow,
a cool and refreshing shade, has also been evolved. Irises of this colour and the new pinks are being raised by the battalion in the U.S.A. and they will no doubt be still further improved.
Depth o f colour is the goal o f the breeders for pink, while the citron-yellows need improvement in form and size. There are also new shades among the blends and the latest so-called henna ones are most pleasant. The colour is not
in the slightest degree dull; it is a bright, reddish brown “with an infusion o f rose, and it is striking at a distance. Another innovation is the evolution o f ruffles on the petals. Older Irises generally possessed smooth petals—described as “ classical” or “ tailored”—but nowadays a large number are delightfully waved and
ruffled. This ruffling, besides giving an air of lightness to the blooms, has a
practical side as it strengthens the petals and gives them power to withstand wind and rain. A minor refinement which has appeared is laciniation o f the petal edges; in some cases this is so marked that the edges appear to be crimped.
There is still room for the tailored flowers but it must be admitted that the newer frilled and flounced beauties do tickle the fancy. Further advances are being made towards a black Iris and some very rich pieces of colour have already astonished us, but the deep yellows, except for those newest ones verging on orange, do not show any striking improvements. Amoenas, those Irises with white standards and coloured falls, are stubborn things and the normal ‘white and purple pattern is only slowly being refined and brought up-to-date. From New Zealand, however, have come the newest Amoenas done in white and yellow; other combinations will probably follow in their wake.