Blooming Ahead

This month’s article will explore choosing, planting, and caring for them for best performance.

Bulbs, corms, and rhizomes are all herbaceous perennials that create adapted storage organs made up of modified plant tissues which allow the bulbs to store energy throughout the dormant period and survive below ground. The difference between a bulb (such as a daffodil) and a corm (for example a gladioli) and a rhizome (Iris for example) is that a bulb is made up mainly of modified leaves attached to a flattened modified stem - in the centre of the leaves is the undeveloped flower bud (you will see the layers of modified leaves when you cut them down the centre, just like in an onion). Corms and rhizomes are made up of modified stem tissue with nodes (growing points) visible where the stems and leaves emerge during the growing season. Many will produce ‘contractile roots’ which can push the bulb, corm, or rhizome up to the surface during the growing season to benefit from the ripening effect of the sun, and then pull

Caroline has been a lecturer in horticulture for 20 years and now runs a nursery and ‘garden craft’ courses in the Haute-Vienne at Le jardin créatif them lower down into the ground during the dormant season.

It is very important that the leaves are allowed to photosynthesise and create sugars for storage over winter. Roots have access to nutrients so that the bulb can generate enough stored energy for healthy growth and flowering the following year, otherwise they will come up ‘blind’ (with no flowers) or decline in size and eventually lack the energy to grow at all. Therefore, the practice of tying up the leaves or

Alliums cutting them back straight after flowering is not a good idea as it hinders their ability to produce enough stored food to last through dormancy and for the first flush of growth. Unfortunately, the leaves can look scruffy as they start to yellow and die back but it is important to allow this natural process.

As a general rule bulbs should be planted to twice the depth of the longest dimension of the bulb (i.e if the bulb is 8 cm at the longest point, you should dig a hole at least 16cm deep, but in hot dry areas you can plant them slightly deeper to avoid them drying out too much).

Always break up the soil at the base of the hole and add some rich organic matter if you have poor soil and add some sharp sand if your soil has a waterlogging tendency. For pots and in the border, plant them in groups to get a better effect; they will bulk up over several years to create more impact.

Growing in pots: a nice way to give a splash of spring colour. You can layer the bulbs to get a longer season of interest from the container, planting the larger bulbs deeper in the compost, creating layers, finishing off with smaller bulbs such as crocus. Cover each layer with a couple of inches of compost. Bulbs grown in pots should be treated as a temporary display because they do not have access to the mineral nutrients in the soil and will not have enough energy to survive and give a good display year on year, so it is best to plant them out into the garden after they have flowered and gone dormant and start with fresh bulbs the following year. You can move the pot somewhere out of the way while the leaves die back.

Growing in a mixed border: prepare the planting hole (the aforementioned width/depth ratio). To avoid having the fading leaves on view plant them amongst or behind other plants which will help to hide them. Remember that most of them will emerge before other plants so even quite short bulbs will be visible and other perennials will come into growth as they start to fade. Iris is particularly untidy after flowering so it is best to avoid planting it at the front of a border, otherwise you are forever having to take off the brown leaves.

Naturalising bulbs: bulbs can also look lovely naturalised in grass, so if you have a spring meadow area that you don’t cut until early summer, or an orchard etc, it is a nice way to add a bit more interest. This time you want them to look naturally scattered through the grass so the best way to achieve this is to get a handful of bulbs, throw them, and then plant them wherever they land. They will usually be planted singly this way but will bulk up naturally over time and may even self-seed.

When buying bulbs, it is best to get them from a reputable outlet. The ones that come in perforated bags with a little bit of wood shavings or compost in may well have been in storage or in a warm shop for a long time so check the packets to make sure that the bulbs are plump and fresh and show no signs of mould. We buy ours mail order directly from Holland where most of them are produced and have been very happy with the quality. We don’t sell loose bulbs ourselves because they have a very short shelf life, but we do have certain varieties of later flowering bulbs that are happy to spend the summer in pots such as the impressive Eucomis comosa which is summer flowering, several varieties of Nerine which flowers late in the autumn and does very well on poor soils/sharp drainage, and several Crocosmia which are summer flowering.

Here are some of our favourites that we have found to survive the climate here well and give a succession of colour from late winter to mid-summer:

Snowdrops (Galanthus nivalis) & Cyclamen hederifolium for very early interest in shade, followed by crocus and tulips (I particularly love the tiny specie tulips such as Tulipa turkestanica) then come the Camassia, Gladiolus (I have found the gladiolus byzantinus – another specie – to be particularly reliable). Next the alliums begin, followed by the Crocosmia. Later in the year I look forward to the Eucomis and last of all Nerine.

Check out our website for our full plant list and our calendar of courses: www.lejardincreatif.net