Family: Liliaceae
Common Name: Tulip

There are over 100 species of tulips, and many hundreds of hybrids. Most modern tulips are the result of extensive breeding programmes begun in the late 16th century in Europe, and continuing today. Tulips were all the rage 400 years ago as more species were introduced to Europe from Turkey, Iran and central Asia. Tulip species range in height from about 15 cm to around 60 cm (6-24 in), but most hybrids are probably 30-40 cm (12-16 in). They make excellent container plants or cut flowers. Flowers of the species can be bright, clear red or yellow, or cream with pink or red markings. Hybrid tulips may also be red, yellow, pink, white, apricot or deep mauve, with plain or trilled petals, some of the frilled or cut petal types being known as 'parrot' tulips. Tulips with 'broken' colours are known as 'Rembrandt' tulips-the flowers are plain-coloured with streaks, flares or flames of other colours. This is caused by a virus carried by aphids so keep these tulips away from other types. Tulip bulbs are available in garden centers in late summer and early autumn; for a wider choice, contact spe­cialist growers. Species tulips are rarely available except from specialists. With selection, it is possible to have tulips in flower from early to very late spring.

Species

Popular species include T. batalinii, zone 5, with primrose yellow flowers; T. clu­siana, the lady tulip, zone 7, whose white flow­ers are striped with deep pink on the outside; T. kauftmanniana, the waterlily tulip, zone 7; and T. tarda, zone 5, which has petals of rich yellow tipped with white.

Most gardeners grow named hybrids, which are in the 15 divisions of the Tulipa genus. Those most popular for spring bedding include the Darwin Hybrids and the Lily-flowered Group.

Cultivation

Tulips need full sun for at least half the day; and some wind protection. The soil should have a high organic content and be very well drained. If soil is known to be very acid, add lime or dolomite before planting at the rate of about 100 grams per square metre (3 oz per square yard).

In warmer zones, place bulbs in the refrigerator crisper drawer for about six weeks before planting. This is unnecessary in areas with long, cold winters. Plant out in autumn: early autumn in cold areas; late autumn in warmer areas. Plant bulbs 10-15 cm (4-6 in) deep and 10-12 cm (4-5 in) apart. Apply liquid fertilizer when buds appear and again after flowers fade. Water well after planting.

Once leaves appear, give a deep watering every week or ten days if it is very dry or windy. Water regularly in dry times, especially once buds appear. Tulips flower between late winter and mid to late spring, depending on variety and climate. If cutting blooms for the house, choose those not fully open and cut early in the morning.

After flow­ering, remove spent flower stems, give liquid plant food and continue regular, deep watering until leaves begin to yellow. If space is not needed, bulbs can remain in the ground in cold areas. To lift bulbs, dig carefully after the foliage yellows. Allow bulbs to dry (out of the sun), clean them and store in a cool, dry, airy place.

Next autumn, plant as is or remove the large mother bulb (which should bloom) from the centre, for planting where required. The smaller offsets, which may not flower for another year or two, may be planted in less prominent positions. In warm areas, bulbs will not reflower; dig them up and discard.

Tulips are susceptible to tulip break­ing virus, carried by aphids, and a disease known as 'fire' which is a type of botrytis or gray mould. Both can be controlled. If plants become infected with gray mould, avoid planting tulips in the same spot for a couple of years.

Climate

There are species suited to various cli­matic zones. Best grown in temperate to cold climates.