Spanish they may be, but these irises stay ‘English’

Press, 27 February 1981, Page 11

Spanish they may be, but these irises stay ‘English’

W DIARY ■V Derrick ! | Rooney

. 'lrises in the Juno section of the genus include some superb examples of ;bul‘bs whose roots are -never really dormant, no matter how sunbaked the soil around them may get ■in summer. ' These species, which in» elude such varieties as Iris , bucharica, I. magnifies, and the glorious sea-green winter-flowering hybrid, “Sind-pers,” are sometimes separated into a subgenu., Scorpiris, but remain more familiar to gardeners under the old name.

V. They have onion-like bulbs whose foliage dies down fairly rapidly after flowering, and long" fleshy white roots that penetrate deeply into the soil. Unlike most bulbs, these irises do not renew their roots annually. Thus they grow, and multiply, fairly slowly; Iris bucharica, white with a brilliant yellow blotch, stays helathv in my rock garden but after two seasons is still producing only one flower spike. Iris magnifica, which is larger and perhaps should be in the border rather than the rockery, has not flowered; I suspect my plant is virused (a friend who flowered it last November says there is nothing magnificent about it, anyway). “3in'd-perj,” on the other hand, which flowers just bove ground level and at the coldest time of the year, is thriving: it doubles itself every year. These irises will tolerate almost unlimited drought in summer if they are left alone in the ground, but they will shrivel away to

nothing very quickly if lifted and left uncovered. They don’t like being moved, because the fleshy roots are always, broken in the process, and when broken will alwavs rot away, right back 'to the base-plate of the bulb. This is not fatal; the bulb will grow new roots, But in the meantime its progress will be severely checked.

I prefer to grow my spares in pots, so that they need not be distrubed, and the clumps in the open ground are seldom touched by ‘he trowel.

The more conventional, and more familiar, English rises, ren-w their entire root systems every year, but they are never fully dormant.

These are the various colour forms — white, lavender, and purple — the souther/ European Iris xiphioides, and they might as well be called the Pyrenean iris, because their main habitat is the Spanish Pyr-.-.iees. But the Dutch bulb growers who largely control the . European market called them English irises because ’hey obtained their original stocks through England, so English irises they remain. They are not as common as they used to be, partly because many stocks have become virused, and partly because many peop’.o have been disappointed by planting bulbs that have remained too Ion; out of the ground. - The English iris in its natural .habitat is a plant of rocky hillsides and subalpine meadows, where the soil never realty dries out con...leteb, and is kept cool through the summer by the shade of rocks or of tall grasses. It flowers after the other bulbous irises (about or just before Christmas), and the leaves die off very quickly afterwards. The old roots die off, too, but within a few weeks, or a few days in a we

summer, new ones are growing. There is nj need to lift them at all, unless the clumps are becoming crowded or they need to be fed, but if they are lifted it should be done smartly — no moe than i. • month ’fter the leaves have shrivelled, and usually before the seeds are ripe (these can be harvested, in their pods, ripened off inside, and sown in autumn; they will come up in spring, and will make flowering plants in three seasons). When I lifted a couple of clumps in my garden a

week ego, the old flowerstems were still green and plump at the base, but the bulbs were well ripened, and surprisingly, in spite of the drought, had multiplied well. They will have to be back inthe ground, or potted up, by the end of this week, so that their new roots can get a good start while the ground is still warm. Nothing will show above the ground until spring, but there will ,?e plenty’ going on below ground throughout autumn and winter.

Their South African relative, Moraea spathulata. is an early bird when mating growth, too, and it, like the English irises, is never reallv dormant.

The moraeas, which are all bulbs (or rather, corms), were at one time included in the genus iris, but were separated off because of minor botanical differences; the six floral segments are divided, as in the iris, into three outer petals, or “falls,” and three upright inner petals, known as “stan-

dards,” but whereas in the irises the six petals are united at the base to form a tube, in the moraeas they’ are separate. There are about 50 species, but as they come from South Africa and many are from the winterrainfall areas they tend to be frost tender.

Moraea spathulata is one of the few hardy species, and it is evergreen, even in a very dry summer, like this one, though its underground parts may enter a state of semi-dormancy when the weather gets really dry; I lifted a four-year-old clump in my garden at the week-end, and found that all the old roots had shrivelled. Only the youngest corms had new, white roots. But the foliage, or most or it, was still green and plump.

This is one of those bulbs that always present a problem. Some experts say they resent disturbance, and that clumps, once disturbed, take a long time to settle down to flowering again. But

sometimes it' is a matter of choosing the lesser of two evils.

Old, congested clumps cease flowering, anyway, because the bulbs are packed together, have no room to expand, and are starved. You might ss well grit your teeth, and lift them regardless. But while the books admit this, they are maddeningly inexplicit as to when it should be done. 1 like to do it in February, no later, indeed I like to move all non-bearded irises at this time. In late February there is usually rain in the offing (there is none as I write, but who know’s what the future holds?), the soil is still warm, and there is plenty of time for transplants to gain a new roothold before the frosts. Next year's flowering most likely will not suffer.

I wouldn’t like to lift Moraea spathulata much closer to the end of the growing season, however, because it, like .the English irises, is about to enter its period of most rapid root growth. The white roots on the youngest corms in the clump that I lifted the other day grew half an inch in the couple of days they spent heeled in to a container of potting mix while I scouted around for planter bags.

When the autumn rains finally arrive, as they always do, the roots will be pushing out of the bottoms of the bags in their haste to get into thsi ground. Moraea spathulata has its main growing period in our late autumn and winter. and flowers in early spring. It is a curious plant. The corms are thickly covered with a netting-like tunic, and each has only a single leaf, which grows erect for a couple of feet then flops back to trail on the ground. It is very hardy, and in my garden has never been damaged by frost. The main obstacle to its wellbeing seems to be taxonomists, who have played footsie with it over the years. Once it was Iris spathacea, then it became Dietes spathacea; in more recent years it has flitted about between Moraea spathulata and Moraea huttonii, and had a brief flirtation with M. moggii and M. muddii, too. Fortunately, there is nothing murky about its flowers, which are a bright, clear yellow. Some forms have bronze markings at the eye, some don’t.