A good drainage system is most vital for growing lilies. Precisely speaking, drainage is the first as well as the last prerequisite for lilies. The lily bulbs not only prefer an open soil composition, but also relish humus. At the same time, these bulbs also enjoy a granular constituent in their diet. It is worth mentioning here that lilies grow very rapidly during the period between spring and summer. In effect, this is the time when the plants make best use of abundant water supplies. When the plants are provided with such an excellent start, they become competent to resist mild droughts. However, as in their natural habitats, lilies are happiest when there is sufficient moisture underground when rainfall is inadequate or there is no rain. In the environment in their natural habitats of lilies, there may be no rain for several months. However, they would be receiving their requisite water supply from melting snows. During the winter months, the lily bulbs loathe standing in water for long. Therefore, more than in any other situation, the plants would be very happy to get good drainage. Similar to clematises, even lilies prefer to have their heads in the sun, while their toes remain in the shade. Aside from these few, the preferences and requirements of lilies are not something that could be described as burdensome. For lily species like Lilium auratum and Lilium speciosum lime is akin to arsenic - it kills the plants rapidly. On the other hand, Lilium candidum has a preference for lime. In addition, very different from other lily species and hybrids, it is necessary to plant the bulbs of L. candidum just beneath the surface of the soil - something in opposition to usual behaviour of plants belonging to the genus. Lily species such as Lilium martagon, Lilium monadelphum and a few others would like to grow undisturbed in the same place for several years, maybe hundred years, after they have established themselves in their position. If they get an opportunity, these plants would be eager to expand their territory quite quickly via their seedlings. Then again, often species like Lilium pumilum or Lilium concolor have individual bulbs that are short-lived. In fact, plants of these species produce seeds and then disappear. After a while, their seeds germinate freely giving rise to new plants that start blooming shortly afterwards.
Humus offers several benefits to the plants, including promoting acidity of the soil, keeping the soil well aerated, promoting in drainage and also in maintaining a healthy balance of organisms in the soil. In addition, humus also serves as a sponge, thereby helping to preserve moisture. When applied in the form of surface mulch, humus can hold back weeds, retain moisture and also help in insulating the soil from extreme fluctuations in temperature. Lilies have a preference for both leaf mould and properly prepared compost. Mulches prepared from dead leaves, dead bracken and other similar substance can also prove to be helpful for the plants throughout the year. Applying fresh bracken fronds that are cut and chopped prior to their unfurling are excellent as a potash-rich soil cover. Even shredded bark has an attractive look, in addition to insulating the soil, holding back weeds and conserving water. Moreover, it also helps to improve the composition of the soil. If you apply a mulch layer of anything between 8 cm and 10 cm (3 inches and 4 inches), it would last for about three years.
As discussed earlier, the most important requirement for growing lilies is a site having an excellent drainage. In fact, the success of your lilies largely depends on this particular aspect. If the soil is heavy and soggy, be sure your lilies will not survive for long. Often poor drainage causes lilies to wither, but the loss is attributed to other causes. It has been seen that when the drainage is excellent, nearly all types of lily species as well as hybrids will grow robustly irrespective of the soil condition. Perhaps, deep sandy loam, especially when it is aerated well and allows water to drain freely, is the best soil for growing lilies satisfactorily. However, you should not be discouraged even if you have clay soil in your garden. You can still grow lilies. In fact, clay soils contain high amounts of nutrients and possess the capacity to produce strong as well as healthy lilies, provided the physical attributes of the soil are dealt with in an appropriate way. Although it may seem unbelievable, a sloping site is excellent for preparing a lily bed. You should never overlook such as site, particularly if the soil allows free passage of water. If you are growing lilies on a flat land, you can install a tile or any other drainage system in order to take away the surplus water. It is important to note that simply hollowing out a deep opening or a channel in a heavy soil and placing some rocks at its base does not essentially provide a satisfactory drainage system. You need to develop a system that will help to drain the water freely from the site where you are growing lilies. If this is not done, the trench or hole will eventually turn into a sump, thereby creating a burial ground for the lily bulbs. When you are preparing a bed especially for growing lilies, it will be beneficial if you raise the bed above the level of the soil in the region. Raising the bed will help to prevent unwanted high levels of moisture in the top layer, about 15 cm to 25 cm (6 inches to 10 inches) of the soil. Commercial lily growers have hugely benefited by employing this raised bed technique. In fact, commercial growers built beds measuring about 120 cm (4 feet) in width and about 15 cm to 20 cm (6 inches to 8 inches) high. These raised areas usually have a 30 cm (1 foot) wide path between the lily beds. Including coarse sand, crushed pumice or washed gravel helps to open up relatively heavier soils and, at the same time, increases the water flow. However, you should never add unwashed, crushed rocks to clay soil because it will eventually form a mass similar to concrete. You can obtain the same advantage by including coarse organic substances like bark dust or commercially available compost. Even adding lime will help to change the structure of soil by flocculating soil particles and enabling enhanced movement of air and water. You should know that sandy soils usually have very poor humus content and, hence, they need to be modified by adding organic matters having a fine texture. Use of compost, well-decayed manures, leaf mold or well decomposed bark dust is ideal for this purpose. Most of us are aware that lilies flourish when they are grown in fairly fertile soils compared to a poor substrate. Therefore, it is best to enhance the quality of soil much ahead of planting the bulbs by digging the soil meticulously and slackening the subsoil, wherever required. In addition, it is recommended that you add properly decomposed organic matter prior to planting the bulbs. You can modify the soil best by incorporating cow or horse manures, but ensure that the manure is aged enough. It has been found that the best quality lilies grow in soils that have been modified by adding generous amounts of cow or horse manures. Nevertheless, you need to be cautious while using manures, as they can not only be of nutritional value, but also be responsible for promoting insects and diseases. Manures also increase the acid levels of the soil, which is considered to be perfect for the growth of the fungus Fusarium. Nevertheless, you can avoid this problem if you use the manure in the form of mulch instead of mixing the manure with soil.
All lilies have a preference for the typical soil conditions, including a well-drained soil capable of retaining moisture. Despite appearance, the above mentioned conditions do not contradict each other. When we say free-draining, we mean that the soil should be able to readily drain any excessive water, allowing enough moisture, which is generally retained in humus, to provide the plants. If the soil is wet or there is stagnant water, it will result in the lily bulbs to rot. If you find that the soil in your garden has a propensity to be wet, it is essential to install some drainage system. On the other hand, you may build a deep raised bed having superior quality soil in order to lift the bulbs above the ground in the adjoining area. You need to lighten heavy soil by adding humus and grit. Humus can be included in the form of compost or manure. However, before applying manure or compost, you should ensure that they are well-decayed. On the other hand, if the soil in your garden is dry, you need to add organic materials to it. Adding organic matter will not only supply the plants with moisture that is retained in their fibrous texture, but it will also provide the plants with the much needed nutrients, which might have been washed away due to rapid draining of the soil. In order to grow lilies successfully, you should also ensure that the soil has a good depth. Moreover, you need to prepare the soil to a depth of no less than 20 inches (50 cm). If necessary, you should undertake double digging with grit and humus. This can be achieved by adding grit and humus to the lower and upper spits. It is advisable that you prepare a reasonably sized area and make sure that if any water accumulates at the base of the bed, it can be drained away. Preparing small areas may actually turn into sumps and these may be partly filled with water, thereby causing calamitous consequences to your lilies. If you add properly decomposed manure or compost to the soil when you are digging the earth to prepare the bed, you need not add any fertilizer at the time of preparing the soil. On the other hand, if you have not added any compost or manure to the soil, then you should add a general fertilizer having a balanced formula and blend it with the soil using a rake. Once you have planted the bulbs, you can top dress the soil with a fertilizer rich in potash content. If you wish to grow lilies successfully, you should ensure that the acidity of the soil is around neutral. Precisely speaking, the pH of the soil should range from 6.0 to 7.0. You can ascertain this by checking the soil with an ordinary kit used for testing pH. These kits are available at nurseries and garden centers in your neighbourhood. In the case of a number of lily species and hybrids, it may be essential to amend the soil pH by adding lime to the soil to increase its alkalinity. On the other hand, some soils may require humus, which has a propensity to raise the acidity of the soil. However, most lilies will thrive well in soils having pH 7. In such cases you will not be required to adjust the pH of the soil. Here is a very important point that all lily growers should always bear in their mind. After you prepare the soil, you need to eliminate all perennial weeds from the bed as well as the surrounding area. You can achieve this by hard weeding or even by using chemical herbicides. When the lily plants have emerged from the soil, it is necessary to ensure that they are not disturbed in any way, as these plants are generally very delicate. If you try to get rid of perennial weeds during this stage it may cause harm to the plants and the damage cannot be mended till the next season. However, annual weeds are not very important, because nearly all of them have surface rooting. However, they can exhaust nutrients and moisture, in addition to harbouring pests and diseases.
The type as well as the quantity of fertilizer that you need to feed your lilies depends to a great extent on the fertility of the soil. In case several other types of plants are already growing well in the vicinity, chances are there that you will not require any fertilizer at all. Nearly all types of lilies have a preference for a somewhat acidic soil ideally having a pH between 6.0 and 6.5. It is advised that you apply a complete and properly balanced fertilizer that contains nitrogen, phosphorus and potassium usually in equal proportions (for instance 15-15-15) to ensure that the plants have a robust growth. Sometimes, especially when the soil is highly acidic, it may be necessary to apply garden lime to the soil. On the other hand, if the soil in your garden is very alkaline, it is recommended that you grow lilies in elevated beds that contain acidic compost. Alternatively, you may also grow your lilies in containers. In addition, several gardening products are available in the market that make lime soils more acidic. However, it has been found employing such products are not as satisfactory as using the methods mentioned above. There are a number of lily species that have their natural habitat in limestone areas and, hence, possess the aptitude to put up with alkaline soils quite well. It needs to be emphasized here that applying excessive fertilizers to lilies may prove to be counter productive and actually harm the plants. This is mainly because too much fertilizer encourages soft growth, thereby making the lilies vulnerable to diseases to some extent. It has been found that heavy soil or those that contain elevated amounts of humus are naturally high in nutrient content too. In such cases you hardly need to fertilize the soil. Even if you need to, be very judicious while applying them. If you are using artificial or chemical fertilizers, it is best to apply them when the shoots of lilies are in their spear stage - just prior to the unfurling of the leaves. In addition, you may gently work some properly balanced granular fertilizer (preferably in the ratio of 12-12-12) into the soil in the region of each individual plant. In fact, any six-month slow-release granular fertilizer like Osmocote, with a 20-20-20 formula, would be ideal for the purpose. Applying this type of fertilizer once would be sufficient to keep the plants content for the whole season. In earlier times, many gardeners scraped away a few centimetres (ideally an inch) of the soil immediately when the lilies emerged and reinstated it with a mulch of properly decomposed horse or cow manure. This practice was undertaken with a view to sustain the health of the lilies and improve their vigour. You may also use other well-decayed composts for this purpose.
If you do not wish to obtain the seeds of your lilies, it is essential to get rid of all young or immature seedpods. When you do this, it helps the bulb to store maximum amount of food possible. In addition, during fall, after the frost has been quite harsh to stop all leaf formation, you need to cut back the stems to the ground. If possible remove the stems and burn them, as it will help in eliminating all disease-bearing organisms from your garden. At the same time, ensure that you mark the place underneath where the bulbs are lying using a stake, as this will prevent any damage to them while you are working in the inactive bed.
Lily aficionados need to be especially careful while using herbicides to check weeds. You ought to bear in mind that these chemicals may work differently depending on the soil conditions and climate. In fact, it is highly recommended that you use Round-up (whose main ingredient is glyphosate) to control weeds prior to the emergence of new lily shoots from their bulbs. Round-up is a wonderful herbicide that is even efficient in checking perennial weeds like bindweed, Canadian thistle, crabgrass and dock. If you apply this herbicide timely, it will eliminate these weeds completely. To obtain the best results, you should apply Round-up in spring. In fact, you should apply it at a time when the weeds have sufficient foliage that can absorb the chemical, but much before the ornamentals like lilies appear close by.