Tulip

Light and exposure

The tulip wants full sun to flower well and hold itself upright. Choose an open spot, a bed, a border or a rock garden, that gets direct light for a good part of the day in spring. In shade, the stems stretch, flop, and the flowers open poorly.

Since the tulip flowers early, before the trees leaf out, you can place it under deciduous shrubs or at the foot of a hedge: it enjoys the sun of late winter and early spring, then keeps a low profile when the shade returns. In a pot on a sunny terrace, it also looks very fine.

Watering

In the ground, the tulip usually makes do with the spring rains and asks for no particular watering. The soil stays cool at this season, and the bulb has built its reserves. If spring is exceptionally dry at flowering time, moderate watering prolongs the flowers a little.

The real trouble is not the lack of water but the excess. Through the cold season, waterlogged soil rots the dormant bulb. In a pot it is even clearer: never let water sit in the saucer, and cut watering right back once the foliage yellows, when the bulb goes to rest.

Soil and repotting

Drainage is the crucial point for the tulip, more important than soil richness. The bulb rots in heavy, waterlogged ground, a very common case in a clayey garden and under a rainy winter. A light, sandy soil that does not hold water suits it ideally.

If your soil is heavy, the saving move is simple: add a handful of coarse sand or gravel to the bottom of the planting hole, under the bulb, so the water drains away and does not sit against it. Plant deep, two to three times the height of the bulb, in loosened soil. A little ripe compost at planting helps recharge the bulb, without excess of fresh fertilizer.

Temperature and humidity

The tulip is perfectly hardy, from USDA zone 3 to zone 8, and cold does not scare it, on the contrary: the bulb needs twelve to sixteen weeks between two and seven degrees to trigger its flowering, which any temperate winter offers naturally. So there is no need to protect it from frost, it is even a good thing. Under too mild a winter the chill never adds up and the flower stays down in the bulb: that is where you pre-chill the bulbs in the fridge before putting them in the ground.

What it fears is the combination of cold and standing damp. A dry bulb withstands severe frosts, a bulb in waterlogged frozen soil rots. Plant before the hard frosts, once the soil has cooled to around ten degrees, so the bulb roots a little before the cold season, then let winter do its work, it works for you.

Pruning and upkeep

After flowering, cut off the faded flower to stop the plant from exhausting itself forming seeds. It is a useful gesture, especially if you want fine flowers the following year: the energy goes to the bulb rather than to the seeds.

However, do not touch the foliage at all while it is green. It is the foliage that, by catching the sun, recharges the bulb for the year ahead. Let the leaves yellow and dry out completely, which takes four to six weeks, before removing them. Cutting the green foliage for the sake of tidiness is the classic mistake: the bulb stays weakened and the next flowering disappoints.

Pests and diseases

The most common disease in a mild, damp climate is tulip fire, a botrytis (Botrytis tulipae) that appears in mild, wet weather. It shows as brown or grey spots on the leaves and flowers, which deform and become covered with a grey felting. Remove and discard the affected parts, air the plantings, avoid wetting the foliage, and do not replant tulips in the same spot several years running.

On the animal side, the bulbs attract the greedy. Voles devour them underground through the cold season, and squirrels dig them up just after the autumn planting. Against them, plant a little deeper, firm the soil well, and you can protect precious bulbs with a fine-mesh wire buried, or a bulb basket.

Propagation

The tulip multiplies naturally by offsets: the mother bulb produces small side bulbs each year. You can separate them in summer, when the foliage has dried and you dig up the bulbs, then replant them in autumn. The smallest will take a year or two before flowering, but it is free and true to the variety.

Sowing exists but remains a matter for the patient and for botanists: it takes several years, sometimes five to seven, before a seed gives a bulb able to flower, and hybrid garden tulips do not resemble their parents. For a garden, dividing the offsets is the only reasonable route.

Toxicity

The tulip bulb is toxic if eaten. It contains compounds (the tulipalins) that cause digestive upset, drooling and malaise, a real risk for children and animals that might mistake a bulb for an edible onion. Store the bulbs out of reach.

Repeated handling of the bulbs, especially when planting in large quantity, can also cause skin irritation, known as tulip bulb dermatitis: redness, itching, sometimes cracks at the fingertips. Nothing serious, but if you are planting a lot, wear gloves.

Month-by-month care calendar

Green Hub tips

• Plant in autumn, never in spring: once the soil has cooled to around ten degrees and before the hard frosts, for flowering the following spring.
• A handful of sand at the bottom of the planting hole saves the bulb from rot in heavy soil and under a damp winter.
• Never cut the foliage while it is green. Let it yellow completely: it is the foliage that recharges the bulb for the next flowering.
• For tulips that come back faithfully every year, bet on the botanical tulips: the large garden ones degenerate fast and are often treated as annuals.
• The bulb is toxic if swallowed and handling it can irritate the skin: store it out of children’s reach and put on gloves to plant in quantity.