Location and Planting
Soil and Site
Lilies are generally of easy culture, if a couple of key requirements are met. The number one need of all lilies is a well drained soil that will retain some moisture. A wet soil placement is a death wish for lilium bulbs. A wide range of soils may grow lilies well and this includes clay. Clay does, unfortunately, retain water for long periods, so it is wise to not plant lilies in areas that are of low elevation in combination with this type of soil. Adding compost, sand and other aerating materials to clay will help lilies to perform better in the garden. In a perfect world, soil that is friable and has rich organic matter would work best, but garden soils range far and wide. Even with this in mind, Lilium will grow well in very average soils.
Lilium love sun, but can be easily placed in semi-shade conditions. Shadier placements will produce longer stems that may not be as strong as a plant in full sun. The plants are adaptable, however, and will respond nicely to less well lit environments. Afternoon shade is actually beneficial since it doesn’t allow the soil around the bulbs to become so hot and dry. Lilium do not like hot soils, in fact, Orientals and many species prefer cool soil conditions.
Lilium can be planted in spring, summer and fall. Spring planted bulbs will produce shorter stems and often less flowers the first year, due to lack of an established root system.
Lilium can be readily moved in the summer as well, while the plants have flowers and foliage on them. It is recommended that, when transplanting in the summer, the plants are cut back half way and watered in well. The flowers can then be put in a vase and brought indoors for further enjoyment. Summer transplants often lose their foliage early and do not look prosperous, but will almost always come up the next year looking like nothing had been done to them.
Fall planting is preferable, since root growth occurs before growth initiates in the spring and the plants produce more robust stems and greater numbers of flowers.
Again, select a site that is well drained. Dig a hole that will easily accommodate the bulb and allow spreading of its roots. The hole should be 3-4 inches (7-10 cm) deep for smaller bulbs and for the larger trumpets and orienpets 4-6 inches (10-15cm). We prefer the six inch depth for Lilium that produce very long stems, as this allows for a sturdier foundation to support the plant. The soil at the bottom of the hole should be loosed another six inches so that new rooting can occur easily.
Spacing of the bulbs should be a minimum of 12 to 18 inches if they are to be planted in groups. Remember, that the single bulbs will give rise to many new bulbs, in coming years, to create a larger clump formation. Many gardeners will plant Lilium in large groups by digging a very large hole and placing the bulbs at various distances within the excavation. This works very well and is often a time saver. Building a slight mound over the planting helps water to drain away and is recommended here in northeast Wisconsin.
Mulching is usually not necessary, but it does help to prevent frost heaving in the first year of growth. If Lilium are grown in a hot location, that becomes dry quickly, a mulch can aid in keeping the roots cool and moist.
Once the bulbs have been placed in the holes, cover them with soil and lightly pack the soil down. If the soil is dry, a soaking of the soil will help to get them started.
Lilies are a fairly straightforward plant to grow, but a few pointers may be of help. Spring is a wonderful time to enjoy emerging Lilium plants. The gorgeous deep green whorls are beautiful and interesting; they are also incredibly brittle. Careful marking of plantings is advised so that the emerging plants are not inadvertently stepped on. Unfortunately, Lilium are favorite meals for both rabbits and deer. Protection from rabbits and deer are especially important in spring, if these critters are common in your area. Wire cages are effective, as are repellents if this is a problem for you. Plants are often presumed dead by gardeners when they do not see them in the place they were planted. In actuality, the plants may have been chewed to the ground by an animal before the gardener took note of their emergence. Even if this misfortune befalls a Lilium, it will, in all likelihood, come up again the following year!
In 2010 we had a very late frost that destroyed nearly every Lilium plant in our sales field, or so we thought. In the spring of 2011 we saw nearly every plant come back up, in some cases a little smaller, but most looked great! Patience will reward the gardener when growing this plant.
As summer arrives a quick look at the progress of the Lilium plants is always a good idea. At this time the stems are reaching maturity and flower buds are beginning to show. Very tall stems will likely benefit from staking. Without staking the stems may break or lean as the heavy flowers enlarge and open. Planting Lilium next to fences is an excellent idea, as the fence serves as permanent stake. Watering may also be a consideration at this time. Lilium require moist soils at all times in order to perform to their fullest. Soaking the ground is a great way to water, but not overhead watering. Overhead watering can encourage the formation of disease and create the perfect environment for powdery mildew and botrytis.
Autumn is the time to begin cleaning up the once beautiful stems. Once the stems have turned yellow and leaves have dropped or yellowed they should be cut to the ground and removed from the site. By doing this, any diseases that impacted the plants the previous growing season cannot re-infect the plants in the coming summer. Watering may be necessary if drought is impacting the area. Even if the plants are not visible, they are still growing and making new roots.
Division and Transplanting
Again fall is the key time for dividing and transplanting Lilium. Typically Lilium will need division every 6 or 7 years, some varieties less time, others more. The bulbs may be separated before the clumps reach large size if wanted.
Before transplanting or dividing the plants, have a reason to do so. Are the stems in the clumps smaller and more numerous than they once were? Do you have a new location that you would like to spread the bulbs to? Do you have friends you’d like to share your plants with? These are all great reasons to move and divide the clumps.
Division should occur after the plants have gone dormant (stems above ground have died). When digging the clumps many small bulbs may be attached to the stems below the ground; these may all be separated from the stem and planted singly. The bulbs below the stem will likely be larger and may have many sections. These sections can usually be broken apart by simply applying pressure away from the center of the mass. All of the above mentioned can now be planted as described in the planting section.
Other Forms of Propagation
Simple division of the bulbs, as described above, is the most common form of Lilium propagation. Other propagation methods range from planting bulbils (black pea-like proliferations found at the leaf axils on some varieties), tissue culture and bulb scale propagation. Tissue culture is used commercially to propagate many identical plants at once and isn’t a likely choice for the average gardener. Bulbils and scale propagation are relatively easy ways to multiply any cultivars one might want more of.
Bulbils are the small black spherical shaped proliferations found along the stem of certain Lilium cultivars. These may be collected just as they begin to drop naturally and should be planted an inch or so below the ground. They will take two to four years to develop into blooming size plants, so be patient.
Bulb scale propagation is a bit more involved, but basically involves peeling away some of the scales enveloping the bulb and keeping them in a warm damp place for a couple of months. This is usually done in the fall during transplant of the Lilium. After awhile the scales will begin to grow many small bulblets on their surface. These bulblets may be removed after a time and chilled in the refrigerator for three months and then planted in the garden come spring. These will also need to be planted shallow and will require some two to four years to bloom (sometimes less, depending on the cultivar).
For further information on growing and propagating Lilium we recommend the book Let's Grow Lilies. This small book is load with outstanding information covering almost all aspects of this Genera. The book is hand illustrated and at first glance looks like something done in the 1960's for young adults. In reality it is highly detailed and contains very accurate understandable text and images.