How to grow lilies: choose the group, then the planting depth

A few lily bulbs can give a border a strong summer focal point without occupying much ground space. Their stems rise through lower planting, and the flowers bring anything from bright Asiatic color to the perfume of an Oriental hybrid. Choose for the site and the people and animals using it, as well as for the photograph on the packet.

This guide covers true lilies, Lilium. Daylilies, calla lilies and water lilies are different plants, even though their common names encourage everyone to put them in the same mental bucket.

True lilies and daylilies are extremely dangerous to cats. The FDA warns that leaves, flowers, pollen and even vase water can cause severe poisoning. A pollen-free flower is not a safe workaround. If cats have access to your home or garden, choose a safer plant instead of relying on keeping a lily just out of reach.

If a cat may have contacted or swallowed lily material, pollen or vase water, contact a veterinarian immediately. Do not wait for symptoms. This matters for cut flowers as well as plants growing outdoors.

Asiatic hybrids commonly offer vivid colors and are often unscented. Oriental and trumpet lilies are useful where fragrance matters. Martagon lilies have smaller, reflexed flowers and can suit light woodland conditions. Check the height as well as the group: a compact container lily and a tall border cultivar need different support and root space.

Soil preferences also differ. Oriental lilies generally prefer acidic conditions, while other groups tolerate a wider range. Do not add lime to every lily planting by default. Choose a plant suited to your soil or use an appropriate container mix where a particular group needs different conditions.

Where fragrance is strong, consider the position near a seat or open window before filling a whole container with scented varieties.

Plant sound, firm bulbs promptly during the appropriate season, commonly autumn or spring. Avoid shriveled or moldy material. Give the roots freely draining soil and a site with the light required by the named lily; deep, dry shade and waterlogged ground are both poor starting points.

Depth depends on bulb size and rooting habit. Some lilies make roots above the bulb along the stem and need a deeper planting than basal-rooting types. Lilium candidum is an important shallow-planted exception. Follow the named plant’s instructions rather than burying every lily 8 or 12 inches deep.

Use containers deep enough for that root system, with drainage holes. Put supports in before planting where possible so later stakes do not pierce bulbs.

Water actively growing plants during dry spells, checking the soil rather than following a fixed weekly dose. Container lilies can dry quickly once tall stems are in leaf. Allow excess water to drain and avoid leaving bulbs in a saturated pot.

Feed according to the growing medium and suitable bulb or flowering-plant guidance. Inspect foliage for damage and pests, including lily beetles where present. Identify a problem before choosing treatment; routine fungicide applications are not a requirement for every healthy plant.

Remove spent flowers if seed is not wanted, but keep healthy stems and leaves until they yellow naturally. If cutting flowers for a vase in a cat-free setting, leave a useful amount of foliage on the plant. The bulb still needs the plant above ground after the last flower has gone.

Once dormant, container bulbs can be assessed for crowding and repotted or planted into suitable ground. Seed propagation is possible but slow and variable; a packet of hybrid seed is not a quick guarantee of the pictured flowers. For a dependable display, sound named bulbs and appropriate planting are a more direct starting point.

In areas where red lily beetle occurs, an inspection of the leaf undersides is more useful than spraying after noticing a few holes. The RHS describes bright red adults with black heads and legs, orange-red eggs below leaves, and larvae concealed beneath a dark, wet coating of their own droppings. A stationary black blob may therefore be worth a closer look.

Examine an entire stem, including lower leaves and developing buds. Turn leaves gently and look for the insect itself, not just damage that may have been made days earlier. Do not assume every red insect is lily beetle or that every hole has the same cause. Photograph an uncertain identification and compare with local extension or RHS material before acting.

For a small planting, hand removal may be practical. Check again as the plants develop rather than considering one clear inspection proof that the whole season is safe. Keep the assessment proportionate: the RHS notes that lilies can tolerate some feeding, while heavy early defoliation can reduce bulb size.

Record three things if the problem recurs: the first new damage, the life stage found and how much healthy foliage remains. This makes it easier to distinguish a few visiting adults from a developing infestation. If you need further control advice, use guidance for your location and a correctly identified pest; a treatment for a different beetle or a different crop may not be appropriate.

Do not remove otherwise healthy leaves just to make a partly chewed plant look clean. Those leaves still contribute to the bulb's next season. Equally, a beautiful flower above a stripped stem does not mean the foliage loss was irrelevant.

Keep this garden inspection separate from the cat-safety decision. A pest-free lily is still hazardous to cats. Where cats may contact the plant, pollen or vase water, the appropriate choice is to avoid accessible true lilies rather than relying on close observation of either insects or pets.