Growing Lilies In Pots And Tubs

by Bob Willard, General Manager of  www.dejager.co.uk

Growing lilies from bulbs in pots and tubs can be so rewarding. The many wonderful, colourful, striking lilies to be bought these days are ideal for the patio, porch, conservatory or the house. I like to use them as last-minute fillers in border gaps to add a splash of colour. If you grow a series of bulbs in pots, planted at different times, you have a continual supply of colourful plants ready to fill any gap.

Generally, the larger the container the better the bulbs perform as moisture and temperature will not fluctuate so erratically. When buying, remember that bigger bulbs give better flowering. Pots of 20cm will take single bulbs: use 25cm pots for 3 bulbs while tubs can take a dozen or more. Drainage holes are imperative as both roots and bulbs will rot without adequate drainage. Use good propriety compost such as John Innes No2 or a compost of two-thirds fibrous loam and one-third well drained decayed leaf mould, with plenty of coarse sand or grit added. Peat based composts will also be improved by adding grit or sand to keep them open in texture.

Put compost in the bottom of the pot, add the bulb or bulbs tucking any roots into the compost. Add more compost to cover the bulbs by 8-10cm, stopping 1cm below the pot top for watering. Then keep the pots in a conservatory, greenhouse, or outside, free standing or in a plunge bed. 

Initially the compost needs damp to encourage rooting. As the lilies get into more rapid growth and the weather becomes warmer, the pots will need to be watched more closely because they are going to dry out much more quickly. Watering should not be done in too carefree a manner; lilies do not appreciate their leaves being wet and dirty, which might cause physical and fungal damage.

Energetic bulbs can soon be looking for extra feed. This is best done as the bulbs begin to colour. If the pots themselves can be shaded this will help to keep the bulbs cooler. Pots outside will have their rate of transpiration accelerated and will dry out quickly. Lilies are remarkably resilient to drought but they are not cacti and should not be allowed to dry out completely; nor do they be need to be sitting in a container without drainage when a rainy period is going to drown them.

After enjoying their wonderful blooms, the wilting flower tops may be cut away. Bulbs should still be watered and fed to build them up for next year. When the stems die in the autumn, the bulbs can be turned out and re-potted. Alternatively, leave them in the pots and just replace the topsoil. Compost can be removed down to the level of the bulb - something that may be easier to manage in larger containers than in small pots thoroughly filled with roots. Pots should then be over wintered out of extreme frost and where they will not be sodden with rain.

As for pests, slugs are partial to Lilies, so protect your plants at all times.  I have been particularly successful in using nematodes. These tiny microscopic worms can protect the bulbs and new shoots beneath the soil’s surface, where 95 per cent of slugs can be found. 

Aphids spread virus diseases, which dwarf and disfigure the plants. Spray with aphid killer when it becomes necessary and destroy plants already affected by virus disease.

In the south of England, Scarlet Lily Beetle is a growing menace, appearing from May onwards. When you see the beetle pick it off the plant immediately. If you want to spray with Provado, only treat the lilies in pots or tubs as it is not licensed for open ground use. Take action as soon as you spot any of the conspicuous adult beetles (up to 6mm long) or their larvae (hump-backed, reddish-yellow and covered in black slime).

P. de Jager & Sons Limited has been selling top quality and top size bulbs for over 140 years. I cannot over-emphasise the importance of size. Top size bulbs really do make a huge difference both in terms of flowering and naturalisation. Smaller size bulbs will be less expensive but the results will be very noticeably inferior