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Martagon and myths. Dr. Ieuan R. Evans
Martagons and myths

 

Author: Ieuan Evans

 

 

Martagon lilies and martagon lily hybrids are hard to grow, they take 7 years to flower from seed, they fail to flower after transplanting, and they are very disease-resistant. Such statements are mythical and unfounded when martagon lilies and martagon lily hybrids are examined more closely.

The species Lilium martagon come in three basic shades of white, pink and maroon, with or without dark spots. Variants of this lily species exist in Europe and Asia, from Portugal to Siberia. Martagon lilies grow in full sun to heavy shade from 70 cm to over 2 m (2' to 7') tall with up to 50 or more pendant Turk's cap flowers. Martagon hybrids are primarily crosses between Lilium martagon variants and the pendant yellow L. hansonii, a native of Korea. L. martagon also hybridizes with the up-facing L. tsingtauense resulting in orange outfacing flowers. Crosses with L. medeoloides and L. x umbellatum have also been made, and more recently, crosses with Asiatic lilies have been successful using embryo rescue technology.

As soon as martagon seed is harvested, it is capable of germination under warm, moist conditions. The seed first forms a miniature lily bulb (hypogeal germination). This miniature bulb, the size of a grain of wheat, forms in 6 to 10 weeks at 15 to 25[degrees] C. The new bulb now requires a further 10 to 12 weeks at 0[degrees] C before it will germinate and produce the characteristic single leaf. In nature, the seeds are scattered in August or September where they germinate in or on moist soil. These miniature bulbs remain dormant over the winter before producing a single leaf the following spring. Under suitable growing conditions, a martagon lily will be fully developed in 3 to 4 years.

After martagon lilies flower in July, or in the case of immature bulbs finish "sizing up" (getting larger), the bulbs grow new roots in August and September in warm, moist soil. If the soil is very dry in late summer and fall, as in 2002 in Edmonton, martagon bulbs may not produce any roots by winter and stems may not emerge above the ground the following spring. In other words, martagon lilies, like tulips and daffodils, should be planted or transplanted in August and September, and watered well to ensure flowering the following year. Your existing plantings of martagon lilies should also be watered well in fall if nature does not provide, in order to ensure needed root growth for proper flower production.

The best time to dig up martagon lilies is mid to late August. The bulbs should be replanted immediately at a 10 cm to 15 cm (4" to 6") depth and watered very well. At this time, the bulb can be transferred to 15 cm (6") pots, 2.5 cm (1") from the bottom of the pot, using a moist soil mix, usually clean, moist peatmoss. Keep the pots warm until November (August to November). The potted bulb will produce new roots readily. The potted lily can either be buried under 10 cm (4") of soil for the winter, kept in a cold garage at around freezing, or kept in a refrigerator for around 3 months, keeping the soil a little moist at all times. Bring the potted bulbs indoors to a sunny window, or into a greenhouse, to warm up in late March and they will flower in May. If the pots are left buried outdoors, flowering will occur in July. I've had a 'Mrs. R.O. Backhouse' bulb produce over 50 blooms this way, and had over 30 blooms on a single 'Sweet Betsy.'

In other words, if you want your martagons to flower in the first year after transplanting or potting up, treat them exactly as you would tulips or daffodil bulbs. They need warm, moist soil to grow roots in August and September and up to 3 months of cold vernalization to flower the following year. Martagon lilies, like tulips and daffodils, only "pout" or fail to flower if you plant them in late October into cold, dry soil. This is much too late for the bulbs to produce roots. Consequently, the martagon bulb fails to produce a shoot at all, or alternatively, produces a modest non-flowering stem. Erroneously, this condition is called "resting," giving rise to the "pouting" myth.

Martagon lilies are very resistant to foliar disease such as botrytis, but can suffer from bacterial spotting and frost injury from severe, late May frosts. Not so! Martagons are very susceptible to botrytis infection especially B. elliptica. This species of botrytis, identified by a world-recognized mycologist, Dr. Lynne Sigler at the Devonian Botanic Garden at Edmonton in June of 2004, devastated my martagon seedlings this late May, 2004 (see photo, p.143).

The botrytis fungi (B. elliptica, B. cinerea and B. liliorum) overwinter as black sclerotes (resting bodies) on diseased stems of many species of lilies. Hosts include Asiatic types and species of lilies such as L. tsingtauense, L. pumilum and L. amabile. During the spring, the flattened, coal-black sclerotia, each only a few millimeters in length, that have overwintered either on dead lily stems or unattached on the soil surface, germinate to form airborne conidia. Occasionally, the black sclerotia will form mycelium that infects the lilies directly. This disease known as fire blight or botrytis leaf blight is the most important foliar disease of lilies. The first symptoms are pale, tan spots on the leaves and stems that turn redbrown. Later on, flower buds and flower petals may also be affected. The oval red-brown spots, which appear on the leaves, may enlarge rapidly causing collapse of leaves, and stems, which turn brown and die. Young and crowded juvenile plants are most badly affected. Large, flowering plants growing in areas of good air circulation may only be lightly affected. In early morning inspections of diseased plants, fuzzy, grey, woolly mycelium can be seen growing on these brown spots. Place the affected leaves in a Ziplock bag, seal and leave overnight in order to clearly see the fungus mycelium and spore masses the next day.

Individual diseased martagon plants may be killed or severely damaged and seedlings in particular may yellow-off and die prematurely, often before the first week of June. Bulbs and bulb scales are not generally damaged unless they are very near the surface.

In the case of young seedlings, following attacks by this fungus, it may take the plants up to 7 years to reach flower production because of annual re-infection drastically slowing down the bulbs' maturation process. Suggestions to help prevent of re-infection include practicing good hygiene and avoiding overcrowding. Epidemics are severe in rainy or misty weather, particularly in late May and early June. Optimal growing temperature for this fungus is around 18[degrees]C to 24[degrees]C, but the fungus can attack martagons at temperatures as low as 0[degrees]C to 10[degrees]C.

Control of Botrytis Disease in Martagons and other Lilies.

Those dead martagons common on the Canadian prairies this year (2004) did not die from the cold, nor did the cold likely lower their resistance. The sharp frosts may have damaged leaves, bent stems, and killed lots of flower buds, but they did not kill the plants, botrytis did. Here's how to prevent botrytis:

1. Avoid crowding of martagon plants, particularly seedlings. Thin out by transplanting crowded seedlings at least by the second year.

2. Grow seedlings where they have good air circulation, in full sun if possible.

3. Remove absolutely all lily plant residues every fall from your garden. Burn them, garbage them or bury them at least 15 cm (6") deep if foliar disease occurred.

4. Rake over and spray the lily growing area in late October with a copper sulphate spray 15 gm per 1 L of water (2 oz./gal.). Use only plastic parts, as the copper is very active on metal parts. Copper, an essential lily micronutrient, is toxic to the fungal resting structures (sclerotia) of botrytis.

Chemical (Fungicidal) Control of Botrytis

In Canada, copper fungicides are permitted, but anything except very dilute copper-based solutions or suspensions will cause foliar damage. Benlate or benomyl was registered in Canada, but this product is now off the market and no longer available as of 2004. In Britain, many effective fungicides are registered for control of botrytis on lilies (see table).

A product of NuFarm Canada called Parasol WP/Fl, a copper hydroxide, is used for fungus disease control in sugar beets and bacterial disease control of dry beans in Canada. This same or similar product is sprayed every 5 days during the outdoor growing season for botrytis disease control on Easter Lilies in Washington State. Up to 15 to 20 spray applications may be required in a single growing season. Apparently, Ronilan and Rovral are the most effective in the UK for botrytis control. In order for these products to be legally used in Canada, lily growers would have to apply for a minor use permit. Minor use permits, if the pesticides are presently registered on food crops, are generally readily approved, but only for commercial use, i.e., for commercial lily growers, but not for home garden use.

In summation, martagon lilies are easy to grow in all of Canada on slightly acidic (pH 6) to slightly alkaline (pH 7) soils, as long as we understand their physiology and disease problems.

P.S.: Once you've grown martagons you'll become hooked and no other lily or plant species will substitute!

 Ieuan R. Evans is a practicing extension and consultant forensic plant pathologist with a Ph.D. in plant pathology and virology.  
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