March is when spring bulbs really come into their own. At the beginning of the month, late snowdrops and early crocuses herald the start of spring, and from then onwards there is a cascade of beauty right through until the alliums remind us that summer has arrived.
It is all too easy to forget spring bulbs after their performance is over, but to get the best from these invaluable plants, they should receive the same care and attention as any other garden subjects, starting when the flowers fade, by dead-heading if necessary and making sure that the bulbs do not dry out, as spring can be a period of drying winds and little rain. Dead heading small bulbs, like snowdrops, scillas, chionodoxa, English bluebells and crocuses is not important – it can be a fiddly job and many miniature bulbs actually spread by seed as well as their bulbs themselves multiplying into bigger clumps. However, larger types, like narcissi, hyacinths, Spanish bluebells, muscari and tulips, will benefit from the removal of the seed heads (not the whole flower stalk, though, as this can help to build up the bulb for the following spring display), although, here again, some species will also spread by seed if the heads are left on.
Like all plants, spring bulbs require feeding to keep them in peak condition. A compound fertiliser such as fish, blood and bone will supply the necessary nutrients for the leaves to boost the bulbs themselves, although specific fertilisers are available. At the same time, check to see if the soil they are growing in is drying out, if so, water liberally after applying the feed; stressed bulbs tend to produce leaves at the expense of flowers in following seasons. It is particularly important to feed and water bulbs grown in containers. With proper care, they should flower well for several seasons before needing to be replaced.
Naturalised bulbs can form overcrowded clumps in a few years’ time. Overcrowding usually results in the production of thin, grassy leaves and fewer flowers. At the first signs, dig up the bulbs carefully, separate into smaller groups, and replant immediately. The following spring you may not notice the difference, but in future years flowering performance will usually return to normal.
Some spring bulbs actually flower better the following year if planted immediately after flowering, in particular English bluebells and snowdrops. These are often sold ‘in the green’, but they can be quite expensive, and often friends are happy to provide you with some when they are dividing their own. You will not need many, as they will quickly thicken up into bold swathes of spring delight.
Never be tempted to cut bulb foliage off before it has started to die off. Like all similar plants, they rely on their leaves to make food, which is then sent down to the bulbs and stored until needed the following late winter, when they start into growth. Tying the leaves into knots, or worse still, cutting them off, will always result in a rapid decline in vigour, and after a very short time, they will not appear at all. It is recommended that at least six weeks should elapse before the foliage is cut back, but the longer it is allowed to remain, the healthier the bulbs will be. If they are growing in grass, mow round them – the lawn will still look tidy. In the border, other plants will soon take over to take the eye away from the fading leaves. Pots of spring bulbs should be moved to an inconspicuous place to finish off, but don’t forget to check them regularly and water if required.