Martagon hybrids, however, can bloom well in the shade, which makes them prized by some growers. For some effects, you can plant your lilies in groups of three or five identical bulbs. Space the plants 8 to 12 inches apart. Depending on the vigor and size of the lilies, keep the groups 3 to 5 feet apart. To know if you need to water your peace lily, check the soil if it is still moist. Also check the leaves of the plant, if it is slightly drooping then you may want to add the frequency of watering the plant. Fertilizer. Adding fertilizer once a month would be enough. Make sure to use water-soluble houseplant fertilizer. These lilies have flowers like balloons, and the petals are joined toward their back. The flowers of this variety are used to create some very beautiful and graceful bouquets. The plant needs a shady garden area. Longiflorum hybrid (division 5) This group includes hybrids from L. longiflorum and formosanum. ) Water After they flower, lilies don t need much water like they used to. Some varieties (Asiatic, Trumpet, Orienpet) adapt themselves well to dry summer areas (if they had enough water during and until flowering time.) Orientals, however, continue to require watering during the dry hot summer months. Another tall lily, Trumpet lilies can grow up to 6 feet, sporting large fragrant flowers in midsummer. They also love cool temperatures. Tiger lilies carry some of the most exotic-looking blooms around in spotted white, yellow, orange and red. In some varieties, the petal edges have lighter shades than those inside. Once you see that the green leaves are starting to grow, you have to supply the plants with nitrogen. To help the plants bloom and to increase the production of bulbs, you have to fertilize these with phosphorous and potassium. The fertilizers must never come in direct contact with the bulbs, so you need to water in meticulously.