Why have some of my lilies failed?
I have been growing tall, white, scented lilies in my garden, and while some grow well, in the past couple of years others have been growing quite spindly with thin stems and not flowering at all. What am I doing wrong or what can I do to help them grow healthier and bigger? They are in a sunny spot and I mulch them and keep them well watered. Should I be feeding them now? Fiona Frame, East Lothian
As you are mulching and watering your lily bulbs, and treating them all the same, I suspect the problem is not with the growing conditions but with the bulbs themselves. I would be inclined to dig up those that are not thriving to see what is going on underground. This is not really the right time of year to dig up the bulbs for replanting, but it is probably a good time to get the best idea if something is wrong – and it sounds like you don’t have much to lose!
If the affected ones are growing together, then just lift a couple. If they are dotted around the garden, pick ones from various places. I think the root system will be poor and there may be signs of pest activity. The bulbs are probably a lot smaller than you would expect.
As with all bulbous plants, it is of benefit to keep the foliage healthy and strong for as long as you can during the growing season, as this is how the plant builds up a reserve of food in the bulb for next year. Deadhead, but let the stems and leaves die back naturally.
If your lilies are growing in pots rather than in the ground, feed them with a balanced general-purpose fertiliser or liquid feed during the growing season. In the ground they should have better access to nutrients, unless they have become overcrowded or are competing with neighbouring plants for food. In this case, it would be better to replant at a better spacing (best done in autumn) or to reduce the competition.