Appropriate planting of lilies is vital for growing plants of these species successfully. This involves a number of aspects like planting time, planting depth, planting techniques and replanting lilies. This article throws light on these vital aspects of planting lilies.
Nearly all lilies grow excellently when they are planted early on in spring. Planting after the fall helps the bulbs of lilies to develop natural contractile or basal roots, which hold the bulbs in place. It is essential for the soil temperature to be warm for the first basal roots to form. Therefore, planting lilies late in cold soil will not produce the preferred root growth. However, Lilium candidum or Madonna lily is a prominent exception. This lily species should be re-planted either towards the end of July or in August, some weeks after its flowering. The bulbs of lilies are completely developed, but dormant during this time. The bulbs will naturally give rise to shoots and produce leaves during the later part of summer or early fall after replanting or if they are allowed to remain in their original place. The plants will spend the entire winter in this stage. This necessitates shallow planting of the bulbs as this will help the leaves to reach the surface of the soil quickly and without any difficulty. When the leaves emerge from the soil, they start photosynthesis. Therefore, it is important not to cover the bulbs of Madonna lily with soil more than 2.5 cm to 5.0 cm (1 inch to 2 inches). The Madonna lily is native to the Mediterranean region and has adapted to arid summer and damp, moderate winter growth habit, which is characteristic of several bulbous plants belonging to warm climatic conditions. Alternatively, you can also plant lily bulbs in spring, whenever the soil conditions are favourable. It is worth mentioning here that following the turn of the year, people who grow lilies commercially store the bulbs at temperatures slightly above the freezing point. When kept in this condition, the bulbs are able to sprout rapidly after being taken out from cold storage and brought in contact with warmer temperatures. Hence, it is wise to purchase the lily bulbs in spring and store them in a cool place prior to planting. In case, the soil conditions do not permit planting the bulbs, it is advisable that you store them in a domestic refrigerator's vegetable bin till the time you are able to plant them. In fact, you should never plant the bulbs until the soil temperature is warm. Also ensure that the soil is not waterlogged at the time of planting the bulbs. You may be tempted to plant the bulbs during a brief fine streak of spring weather. However, such a weather condition may be followed by a wretched cold period, which is barely perfect state for the bulbs to sprout as well as grow quickly.
The ideal depth to which a lily bulb should be planted includes a number of factors, for instance the growth habit of a specific lily species or hybrid, the soil type in which the bulbs are planted, the bulb's size and the climatic conditions prevailing in your area. Along with the basal or contractile roots, nearly all lilies turn out roots from the stem portion that is just above the bulb. Every year the stem roots die along with the stem when the growing season ends. The stem roots are vital for the plants as they serve as feeding roots during their active growth period. Hence, it is necessary to plant the bulbs sufficiently deep into the soil so as to ensure abundant growth of the stem roots. Usually it will be beneficial if you cover the lily bulbs with soil up to a depth of thrice or four times the length of the bulbs (right from their base to the tip). Ideally, you should cover the stem rooting lily having large bulbs, for instance the trumpet hybrids, with soil to a depth of about 25 cm (10 inches). Planting the lily bulbs adequately deep also has other advantages. When you plant the bulbs deep into the soil, it helps them to remain cool even during the summer heat. In fact, it is important for growers to protect the bulbs from the fluctuating temperatures that usually take place in the top layer of the soil. You should remember that high soil temperature often promotes disease development. Several lily aficionados plant the bulbs very shallow with a view to obtain best possible results. However, the Madonna lily (Lilium candidum) is an exception in terms of both planting depth and planting time. This lily species gives out roots only from their bulb's base and never from the stem of the plant. Therefore, it is appropriate to plant Madonna lily shallowly. In addition, you can make some modifications vis-�-vis the planting depth of bulbs depending on the type of soil as well as the climatic condition. If the soil type is heavy, you need to plant the lily bulbs not as deep as planting them in soils that are warmer, lighter, and sandy. On the contrary, if you are growing lilies in warm regions, it would be beneficial to plant the bulbs deeper, as this will help to protect them from elevated soil temperatures close to the surface. If you are planting yearlings or small seedling bulblets, it is ideal to cover them with soil to a depth of roughly 5 cm (2 inches), subject to the size of the bulblets. As the bulblets grow and their size increases, they develop contractile or basal roots, which pull them deeper into the soil. In fact, this is also true for larger bulbs. Provided the composition of the soil permits, the basal roots pull down the bulbs to a level that is favourable for them. While placing lilies, gardeners ought to know that plants of some groups, for instance Orientals as well as hybrids of Lilium lankongense and Lilium wilsonii, usually the stem does not emerge directly upwards from the bulb. Instead, stems of these plants travel horizontally under the soil for some distance before they emerge above the soil surface. This is nature's approach to let the stem roots get sufficient soil so that they can develop properly. However, the chances of this occurring decrease as the planting depth of the bulbs increases. Therefore, lily growers need to give special attention to all species as well as hybrids that have this type of stoloniferous pattern.
Planting of lily bulbs can be undertaken using various different techniques. While little physical effort is required for applying some techniques, others may actually be strenuous. However, the best technique is to plow a hole that has sufficient room for the entire lily bulbs that you want to plant in a cluster. The depth of the hole will depend on the bulbs' size as well as other factors that have been discussed above. For instance, you need to dig a hole having a depth of about 20 cm (8 inches) to plant bulbs belonging to the Asiatic clone called "Connecticut King", whose average length is about 5 cm (2 inches). Prior to planting the bulb, slacken off the subsoil at the base of the hole with a view to make the drainage better. Next, place the bulbs on their bases leaving adequate space between them to allow them to grow freely and achieve full development. If you are growing Asiatic clones, you should leave a minimum space of 15 cm (6 inches) between their bulbs, while the spacing should be no less than 45 cm (18 inches) for relatively taller lilies like Orientals and trumpets. You should be aware of the fact that the spacing also depends on the final height as well as habit of lilies. For instance, if you are growing a lily variety producing an extensively branching inflorescence, they will require more space to display their blooms compared to those with tall and narrow patterns. It is important that you take measures to prevent overcrowding. This is essential for aesthetic reasons. Moreover, overcrowding usually hinders air circulation, thereby promoting various diseases.
Replanting lily species and hybrids is essential to ensure their healthy growth. However, at times it is difficult to determine the precise duration for which a lily clump should grow in the same place prior to moving the plants to a new location. After the lily bulbs have already produced quite a lot of stems, it is usually preferable to divide the clumps during fall and subsequently plant the bulbs in a fresh area of your garden. It has been seen that Asiatic lily varieties grow well when replanted from time to time. Therefore, you need to lift and replant them regularly. Nearly all Asiatic varieties develop numerous bulblets the length of the stem that remains underground. Consequently, the clumps turn out to be extremely crowded and there is a decline in flowering. If you are growing relatively strong Asiatic lily varieties, it is advisable that you lift the clumps and separate them once in three years. Occasionally, you will observe that a lily group may not be thriving as it did in the past. In such instances, you need to shift the plants to a new site and plant them in a fresh soil. This will help the plants to regain their vigour. Ideally, such replanting should be undertaken about three or four weeks following the flowering period of the plants. After you have lifted the clumps and before dividing and replanting them, you should examine the bulbs to see if they are affected by any disease. You need to check for basal rot (Fusarium). It is advisable that you dispose of the bulbs that have been infected severely, while treat the remaining bulbs using an appropriate fungicide and then replant them.