Lilies are exciting plants to grow in the greenhouse. At one time the most popular type was Lilium longiflorum, the white-flowered Easter Lily, but nowadays there are many others which are also grown as pot plants. Those I like to grow for early flowering include Lilium regale, the popular Regal Lily; followed by Golden Clarion, Enchantment and L. tigrinum, with L. speciosum rubrum for late summer and L. auratum whichin late summer and early autumn. All are excellent for the cool or . The bulbs should be potted between September and the beginning of December, the earlier the better. I prefer to use 8-in. pots, putting three bulbs in each. The must be extremely good for will not tolerate stagnant compost. John Innes No. 3 Potting Compost, to which a little extra peat has been added is an ideal growing medium.
In the case of stemrooting lilies, I also add a little well-decayed manure to the mixture. With these lilies only half fill the pots with compost and leave the tops of the bulbs showing above the mixture. They will later be topdressed to bring up the compost level. Pots containing non-stem rooting lilies are filled with compost to within about 1/2 in. of the rim at the time of potting, the bulbs being covered to a depth of 2 in.
The pots can now be put in a cold frame or be stood outside and covered with straw, leaves or even polythene sheeting. Alternatively, they can be placed under the staging of an. No heat should be given during the winter months. As the shoots of stemrooting lilies develop and reach a height of about 9 in., the plants can be topdressed with similar compost to bring the level to within 1 in. of the rim. Staking will be necessary as more growth is made.
The plants, when well advanced, can be brought into the greenhouse in batches, depending on their time of flowering but none, with the exception of the Easter-flowering L. longiflorum, should be brought into a heated greenhouse before March or April. If the plants are allowed to develop naturally they will be stronger with longer-lasting flowers.
The greenhouse should be ventilated freely and overwatering must be avoided.
Keep the temperature below 10°C. (50°F.) if possible. The plants will benefit from feeding with liquid fertiliser when the shoots are 12 to 15 in. high.
In the autumn when the leaves and stems begin to yellow, the plants can be moved to a cold frame. They can be cut down tolevel and the amount of water gradually reduced. They must not, however, be allowed to become completely dry for the bulbs are never really dormant.
Lilium speciosum rubrum can be used for pot cultivation a second time, also L. longiflorum, although it loses some vigour after the first year, but the rest I plant out in the garden. Brief descriptions of the lilies referred to are as follows:
L. longiflorum. White trumpet flowers, 3 ft. stem rooting.
L. regale. The Regal Lily. Trumpet flowers suffused maroon and pinkish-purple on outside, white within and flushed yellow in throat. 3 to 6 ft. stem rooting.
L. Golden Clarion Strain.Trumpet flowers in shades of yellow, gold and orange, 3-½ to 4 ft.
L. Enchantment. A splendid nasturtium-red Mid-Century Hybrid, 2-½ to 3 ft.
L. tigrinum splendens. The Tiger Lily. Rich salmon-orange flowers, 4 to 5 ft. stem rooting.
L. speciosum rubrum. Rose and carmine, purple-spotted flowers. 4 ft. stem rooting.
L. auratum. The Golden-rayed Lily of Japan, huge flowers 9 to 12 in. across, gold on a white ground and heavily spotted crimson. 6 ft. stem rooting.