Lily Flower : Pests and Diseases

Strong, healthy plants are your best defense against pests and diseases. By giving your lilies the best possible care, your chances of attack are slimmer.

Be on the lookout for the bright red lily beetle. If seen, it must be hunted out and destroyed. Both the beetle and their larvae hide in what looks like black tar or bird droppings on the leaves. This can eventually kill the plant. Removing by hand, if possible, is fine. Just be sure to place a container under the leaf so that the beetle does not drop to the ground. Symptoms of virus on lilies appear as distorted leaves, buds or flowers. Most evident is unusual streaking on flower petals or mottled foliage. If affected, pull out and destroy the plant. Do not compost.

Some animals, like rabbits, like to eat the lilies just as they are emerging from the ground. Caging your plants may be necessary, if this is a frequent occurrence. Once the tips are eaten, they will not bloom.

Botrytis

This is a fungus disease, which affects the leaves of lilies, caused by excessive moisture and warm temperatures. The first signs can be white spots on the leaves. In severe cases the whole leaf and stem can become infected and the whole plant decay and collapse. Injury to plants, like frost or hail will make it easier for Botrytis spores to enter the leaf; spraying is strongly advised very soon after injury. The disease is not carried by the bulb so it will not affect flowering the following year. In early stages of infection, if possible remove noticeable spotted leaves. Spraying is highly advisable, and is only effective when foliage is dry. A copper spray can be used or natural remedies such as a baking soda mixture (1/4 tsp. per quart of water) sprayed weekly on the foliage during wet periods can also be used. Good air circulation will help prevent a outbreak. Planting lilies some distance apart will also control infection. In the fall clean up and burn dead stems and leaves.

Lily Botrytis

Basal Rot

This fungus invades the bulb through the roots and basal plate. The symptoms on the growing plants are usually premature streaky yellowing of the foliage. The disease can become present in warm moist soils. As a preventive, avoid over-watering during warm summer months and provide good drainage. As for infected bulbs, you can remove the infected scales, dip the bulbs in a fungicide solution of Benlate, which is readily available to home growers.

Basal Rot

Blue Mold

Because lilies have a high sugar content, bruising or mechanical injury can cause a penicillin mold to form on the injured part of the bulb. This is harmless to the bulb and can be carefully removed. The bulb can be dusted with a fungicide powder and planted as usual.

Blue Mold on Lily Bulb

Virus Diseases

Lily viruses are transmitted largely by aphids. Visible evidence of virus is; Irregular mottling and flecking of the leaves. Reduction in plant size and height. Distorted, twisted growth. Color-breaking in the flowers and leaves. Brown ring patterns on bulb scales.

A few tips to help control viruses are: Destroy clumps of lilies that show severe infection, insuring that all bulbs and scales are discarded. Remove plants showing infection early in the season. Avoid planting lilies next to other host plants like Tulips or lilium tigrinum (also known as the Tiger Lily). Control aphid infections with the use of insecticides.

Lily Viruses

Lily Beetle

Long prevalent in Europe, the lily beetle (Lilioceris lilii) has been reported in eastern North America. The larvae and adult beetles feed on the leaves of lilies. The larva is a yellow grub with a dark head, covering itself in dark, slimy excrement. The adult is up to 8 millimeters (0.25 inch) long and bright scarlet with black legs and antennae. Both life stages have voracious appetites and soon devour entire plants. The eggs are laid on the underside of the foliage. The following controls are effective: Spray plants with contact and systemic insecticides; both are effective. Drench soil with a soil insecticide to kill the mature larvae that live just under the soil surface in winter. Also, avoid transporting infested soil to other sites. Catch adult beetles between the fingers and smash them. The lily beetle has only appeared in a few places on this continent, and with care, it should be possible to prevent any lasting infestation.

Red Lily Beetle

Reference : Lily Pest and Disease , Lily Plant Care

Lily Basic Care

Every garden benefits from the addition of these most versatile and beautiful plants. Equally at ease in containers or in the ground, the choices are wide. Lilies fit in well with other garden plantings because their growth is so upright. They take up very little space and can grow between other plants. The three main divisions of lilies are the Asiatics, the Trumpets, and the Orientals. There are actually nine divisions with more being created to account for the inter-division hybrids. Each of these divisions has sub-groups for the differences in flower shape and direction.

Asiatic

Lilies are the easiest and most tolerant of the lily cultivars. They are available in the broadest range of colours and are distinguished by their lack of fragrance. They are the first of the lilies to bloom. Height : 2-4’(60-120cm). Bloom time in June and July.

Asiatic Lily

Trumpet

Lilies are very tall and very fragrant. These may require staking and are best planted near the back of the border. The colour range is not as varied as with the Asiatics, but the blooms are large and trumpet shaped, often with contrasting colours inside and out and the leaves are generally very thin. Height : 4-6’(120-180cm) Bloom time in July.

White Trumpet Lily

Oriental

Lilies are large, flashy and very fragrant; they are often used as a cut flower. Flower colours are shades of white, pink or red and they are generally broad. They do require an acidic soil and if your soil is too alkaline, it might be best to grow these in a container. Height : 3-6’(90-180cm). Bloom time in August to September.

Oriental Lily

Martagon

Lilies are a unique type with attractive, whorled leaves and clusters of small, fragrant flowers. Very attractive, and able to withstand more shade than other lilies, they make an excellent addition to the woodland garden. It may take several years from seed to flower. Height : 3.5-6.5’(1-2m). Early blooming. Very limited availability due to its slow growth, but highly valued.

Martagon Lily

Lilies do best in full sun but some will tolerate light shade. If too shaded, the plants will lean sharply towards the light. They must be planted in deep, loose, well-drained soil, have access to moisture at all times, and their roots must be kept shaded and cool. Unlike most bulbs, lily bulbs never go dormant and should never be allowed to dry out. The necessity of well-drained soil cannot be overemphasized. Heavy, clay soils should be amended with compost and gritty gravel. Sandy soils also benefit from the addition of compost and premoistened peat moss. Mulch with well-rotted compost or shredded bark to maintain moisture and keep the soil cool. This will eventually break down and improve the soil structure. Plant lilies deeply in sandy soils and less so in clay soils.

General rule : Cover small bulbs with a minimum of 2-3” of soil, medium bulbs with 3-4” of soil and large bulbs with 4-6” of soil. After blooming, remove the dead flower, leaving all foliage intact. This is also an essential step when cutting lilies to bring indoors. As much foliage as possible must be left on the plant in the ground. Cutting long stems will seriously weaken the lily. Allow the stem and leaves to turn completely brown at the end of the season before cutting back to the ground. This allows the lily to regenerate for the following year’s blooms. Cover the small hole made, after cutting, with some soil. This prevents water from entering and potentially rotting the bulb.

This is the best time to divide and/or move your lilies. They can be dug out, (never pulled), and carefully graded for size. New lily bulbs will have formed around the stem of the mother plant or around the original bulb. These can all be planted out separately in the garden to size up for future blooms. No bulb is easier to grow in a container than the lily. The larger the pot, the more room there will be for root development and the more stable the pot will be for tall growing lilies. You can maximize the growing possibilities by under-planting with lilies and planting other annuals or perennials on top of them. These plants add interest and contrast while keeping the lily roots cool. Try growing some pansies or lamium as groundcover on top of the container. Over-winter the pots in an unheated shed or garage or plant directly into the garden.

Reference : Lily Basic Care Reference