Images: Tim Sandall
September is a good time to buy spring-flowering bulbs, especially when planning colourful combinations with other plants. Choosing your bulbs early ensures a wide choice from the healthiest of stock. Planting soon after purchase can encourage better displays and reduce disease problems.
When to buy
Most bulbs are sold in a dry state when dormant. Spring-flowering bulbs, such as daffodils (left) and tulips, are usually available during September. You may find a few
bargains in October but the choice will be
more limited and most bulbs are best planted as early as possible. The bedding-type tulips
are an exception as late planting, even into midwinter, will help avoid infection by tulip
fire. It is also claimed that late planting of Muscari (right) encourages them to produce
flowers rather than foliage.
Selecting bulbs
Summer flowering bulbs including Gladiolus, Eucomis and Eremurus can all be bought in spring. Allium (left) can also be planted at this
time but often make a better display from an autumn planting. Some spring-flowering bulbs are also sold ‘in-the-green’ (in growth with foliage) such as snowdrops, Eranthis, Erythronium and Anemone nemorosa. Autumn-flowering crocuses and Colchicum especially benefit from early planting. Specialist nurseries will have them available from midsummer.
Making the right choice
Select bulbs that are firm and of good size for their type. The larger the bulb the more likely it is to flower. Check that the bulb is healthy, with no obvious signs of damage or disease. Split tunics (the flaky outer membranes), soft necks and sprouting tops should all be avoided. Bulbous woodland plants such as Erythronium, Galanthus and Cyclamen are best purchased from specialist nurseries that despatch damp-packed; dried-out bulbs of woodland dwellers sold in multipacks often establish poorly.
Planting
Plant most bulbs as soon as they are purchased. Spring-flowering bulbs make extensive root growth if planted in early autumn, resulting in a better display. If immediate planting is not possible then keep dry and cool. Tender summer bulbs such as Tigridia and Triteleia are best potted up and planted out later when
the weather warms.
Positioning
Most hardy bulbs are from dry-summer climates and prefer a warm, sunny site with good drainage. Bulbs from cool, moist woodland habitats need corresponding conditions in the garden. Good soil is important as most bulbs have only a short period in leaf before dying back. Thoroughly cultivate and improve the soil with coarse grit and, especially on dry sandy soils, incorporate well-rotted organic matter. Do not dig holes in heavy clay and fill with grit - this merely creates a sump where water collects and bulbs rot. Instead, cultivate the whole area and, where drainage is poor, throw up the soil into a low mound and plant into it.
Cultivation
Plant in groups. Orientate the bulbs with the growing point uppermost and, as a general rule, plant at least two to three times the depth of the bulb, with a similar distance between individual bulbs. Shallow planting results in poor flowering after the first year. The same rule applies to bulbs in pots. Plant deeper on
sandy soils. Bulbs in-the-green should sit at
the same depth they were before lifting and kept well watered.
Most bulbs will benefit from an application of a balanced fertiliser in early spring.
Flowering
It is difficult to get some bulbs to flower again in subsequent years. Flowering is dependent on the physical size of the bulb and, on lifting, the bulbs will often be found to be small. This is particularly the case with bedding-type tulips and the early flowering reticulata-type iris. Many gardeners replace these every year.
Tony Dickerson