With autumn just approaching, it may seem too early to be talking about bulbs, the harbingers of spring, but often gardening is about thinking ahead, and now is the time to be planning and planting any new spring flowering bulbs in your garden.
They are such easy plants to grow - simply plant them and leave them and then enjoy vibrant colour each year, with just a bit of deadheading for ongoing care. They can brighten up your borders, add interest to the bases of trees and shrubs, or be planted in containers, and by carefully selecting varieties you can achieve an ongoing display from very early spring all the way through to summer.
It is useful to be clear on the definition of a bulb: a short stem with fleshy leaves or leaf bases, which is the food storage organ of a plant that sees it through dormancy. A true bulb (for example, narcissus, hyacinth or tulip) contains its leaves and flowering parts inside. Some plants, however, have other types of storage organs which closely resemble bulbs; these organs are corms, rhizomes, and tubers, and they are often referred to as bulbs, although, botanically speaking, they are geophytes - plants which form underground storage organs (this includes both true bulbs and corms, rhizomes and tubers).
Geophytes all bear close resemblance, with subtle differences. A corm, for instance, (e.g. Crocus and Gladiolus), has its leaf parts on the outside rather than the inside, with internal buds. A rhizome, meanwhile (e.g. Canna Lily and Iris) possesses a growing tip, from which the leaves and buds form. Lastly, a tuber (e.g. anemone, dahlia, ranunculus) has “eyes” that develop into roots, shoots, leaves, and flowers. They all have similar growing habits, however, and as it is fairly common and convenient to simply group all of these together and call them bulbs, I shall do so throughout this article.
One of the easiest things to do with bulbs is to naturalise them. While some people think naturalising means growing bulbs in grass rather than in borders, it actually means growing bulbs as they would grow in the wild, naturally. This can be done in lawns, woodland, orchards, wild flower meadows, and around the bases of trees and shrubs, where, rather than carefully arranging the plants into a formal pattern, you simply scatter the bulbs and plant them where they fall, then allow them to grow and increase in number, undisturbed. The resulting clusters form a carpet of colour, which returns year after year, each year growing and spreading. It's a great way of providing interest in areas that otherwise might not bloom, especially in places like under deciduous trees, where conditions might be too dry and shady for other plants. Note though that Hybrids do not come true from seed, and are not reliable plants for naturalizing for uniform colours.
The bulbs will be there for a long time, so it's important for them to be well spaced, and not too close together, as overcrowding reduces flowering. While this may look a little bare at first, it will fill out, though it takes a bulb between 4-7 years to reach full flowering size from seed, so, as always with garden development, it's necessary to be somewhat patient.
If including bulbs in a border, try to plant in substantial quantities, of half a dozen or more, to achieve an impact. You can make good use of early varieties, such as Galanthus and Scilla, by planting next to late perennials. This will avoid bare patches while the perennials are still dormant, and then, reciprocally, as the perennials begin their new growth, they will cover up the fading foliage of the bulbs.
When planting the bulbs, dig the planting holes with a trowel or a bulb planter. The holes should be approximately three times the depth of the bulb. Shallow planting leaves bulbs vulnerable to drying out and to being dug up by squirrels. Break up the plug of soil removed and use this to backfill around the bulb once it is in place.
Ensure that your planting area has sufficient drainage. Bulbs do not like winter wet and are not suitable for heavy clay soils. To improve suitability, increase drainage by digging in grit and organic matter. Also ensure that you place bulbs appropriately for light levels. Narcissus and Crocus will thrive in full sunlight, while Galanthus, Bluebells and Aconites do well in shade.
Bulbs can also be grown in containers, and will benefit from a mix of three parts multi-purpose compost and one part grit. The bulbs should be planted at three times their depth, one bulb’s width apart. Ensure that pots don’t dry out, watering when necessary, especially during active growth.
For ongoing care, deadhead the spent flowers but leave the leaves to die back naturally. This improves next year's growth, with a bigger bulb and productive flowering.
Bulbs are not prone to too many problems. They can, of course, rot during storage, so discard any soft bulbs during planting. Slugs and snails, the ubiquitous enemy, should be removed (personally, I like to then feed them to my chickens!) Squirrels are particularly fond of tulip and crocus bulbs. Some diseases to be mindful of are viruses in narcissus and tulips, grey mould in Galanthus, Narcissus basal rot, and the fungal disease, tulip fire.
If, as sometimes happens, you acquire your new bulbs, full of enthusiasm for planting them, then they somehow remain forgotten somewhere in your potting shed or barn, don't berate yourself too much. Plant them as soon as possible, even if they have begun sprouting. If you wait until the following autumn so it's the “correct” time, they will deteriorate further. Some bulbs store better than others, and they might not perform terribly well in their first year, but at least you can give them a chance.
John and Debbie Wilson www.lejardindesespiemonts.fr