Bulbs are impressive things. They are pretty tough as their job is to be the storage vessel for an entire plant while it is dormant.
Bulbs evolved to allow plants to survive periods of drought, cold and other less than optimal growing conditions (however very few like wet soil especially when dormant). Some plants multiply by growing new bulbils.
Flower bulbs can cause skin irritation so please always wear gloves when handling them. Many bulbs are harmful if eaten, so keep out of the reach of children and pets.
- Store your bulbs somewhere cool, dry and dark.
- Wrap them in paper, keep them in a net or on bone dry sand. Don’t store them in a plastic bag as they may rot.
- Store them out of reach of mice and squirrels.
As a rule of thumb, bulbs should be planted at three times their own depth. There are exceptions to this though, usually with summer-flowering bulbs, so please check the instructions for your particular choices.
For naturalising, planting bulbs no shallower than three times their own depth will help them to survive (again, check with your species).
Bulbs will not do well in very wet soil, so add some grit to the planting hole and make sure there is enough drainage.
- For naturalistic planting, scatter a handful of bulbs and plant them where they fall. Use a bulb planter to make individual holes. This is especially useful in grass where you can place the grass tuft back on the hole.
- Mark the spot where you have planted them.
- If planting in containers, bulbs do not need to be so deep, but make sure they are not touching the outside edge of the pot or they could get frost or heat damage.
- Plant your bulbs where it is recommended for the species – many spring bulbs like full sun but a cooler place to rest during the summer, so if their spot gets overshadowed by trees later on that is not a problem. Planting elsewhere may mean your bulbs won’t flower well.
- If your garden is rural or near woods, you may want to cover your newly planted bulbs with chicken wire to stop them being dug up by squirrels.
- Feed your bulbs especially while the leaves are growing. This will help them keep and build stores for next year’s flowers, rather than using all their energy on this year’s.
- Cut off spent flower stems to prevent the formation of seeds (unless you want them), as these will use valuable resources the plant could otherwise save for next year.
- Allow the leaves to die right down before removing them. This allows the plant to take their nutrients back into the bulb.
- If required, bulbs can be lifted and stored once the leaves have died off. Many summer flowering bulbs can be brought in for winter to keep them frost-free. Planting in bulb baskets can help this.
- Bulbs’ worst enemies are the wet and animals like slugs, mice and squirrels. Protect from these and you should get a good display year after year.
Guide to planting summer flowering bulbs
Plant hardy summer flowering bulbs in the spring, from January if you live in a mild area. From February/March if not.
Be sure to check the planting depth for your bulbs – some summer flowering plants have rhizomes or corms rather than bulbs and these tend to enjoy being closer to the surface. For example, irises prefer to have the top of their rhizomes above the soil and to be unshaded.
Check the directions for planting your non-hardy bulbs (some are half-hardy, some are tender) as they can differ.
Generally they can be started in pots in February in a warmish greenhouse and then moved outside in May when all danger of frosts have passed.
Some bulbs we sell are tender and do better as conservatory plants.
Plant 35cm apart in well drained soil that is moisture retentive in summer, or in tubs. Agapanthus appreciate having their roots restricted and will flower better.
In the winter use 2″ of mulch to protect the plants or move tubs to a sheltered, frost-free position. Some agapanthus are hardier than others.
Start begonias in February – April in trays of light compost at 18C. Place very shallowly with the hollow side up. When leaves begin to appear, pot on, then transfer outside when all frost has passed.
They can be planted out in the garden 30cm apart although cascading begonias will look better in pots. Begonias like moisture and food, so in dry weather water ever day in the morning or evening. Use bonemeal in the compost and add plant food.
Deadhead regularly. Lift begonias in the ground before the first frost then store in a cool, dry place. Bring potted begonias in to a frost-free place overwinter and pot on in spring.
Plant in pots in March to April, two times or so as deep as the height of the bulb. Bring the pots in to a sheltered, frost-free place before the first frosts and allow to dry. Alternatively lift the bulbs, store somewhere cool and dry and replant in spring. Bessera can tolerate a little cold but they do not like being wet.
Plant the corms in spring about 2 to 5 cm deep, depending on size. Will grow best in a well-drained, sunny border. Not reliably frost hardy, chasmanthe will naturalise in warmer parts on the UK. The bulbs grow during the winter in their native South Africa so they may not show leaves until the following January/February.
Plant the bulbs with the top sticking out of the soil – there may be a line on the bulb to show where the soil line has been. Not reliably hardy in colder parts of the UK, will do best against a south facing wall and mulched well in the winter. Keep moist while growing. If in doubt, keep in pots or lift and store somewhere frost-free over winter.
Plant crocosmia in February – April, about 7cm deep and 15cm apart. Plant in moisture-retentive soil in the sun but with a little shade each day. Old leaves and flowering stalks can be cut back in the autumn.
In cold areas, add a couple of inches of mulch in autumn.
Some varieties can multiply well when happy; these can either be dug up in winter and the clump reduced to a few strong corms, or they can be planted in a large pot sunk into the ground to prevent them spreading. Lift the pot every couple of years and replace only a few strong corms.
Plant in the dappled shade beneath trees or shrubs, or in pots. Cyclamen prefer to be dry and cool when dormant in summer. C. hederifolium is probably the hardiest cyclamen for UK conditions.
Plant in April – May 10cm deep and 45cm apart, use bulb baskets to make it easier to lift and store your dahlias for winter. Dahlias can be started in a frost-free greenhouse earlier in the year.
Increase the bushiness of the dahlia if required by taking out the growing tips about three weeks after planting. Most dahlias will need staking or support, and protection from slugs.
Mulch to prevent weeds. Water well during dry spells, deadhead regularly to keep it blooming. Lift and store in a dry, frost-free place over winter unless in a very mild position.
Plant in early spring on a mound of grit with the crown not far beneath the surface of the soil, spreading the roots out around it. Mark where they are so as not to disturb when dormant (with a plant marker).
Lift every three years and replace only the strongest crowns. Try not to shade the roots as this may produce less flower spikes.
Plant in spring in well-drained soil with 10 – 15cm or more of soil above them, 30cm apart, in mild areas only. Mark where they are so as not to disturb when dormant (with a plant marker).
If planting in containers, feed regularly and store somewhere dry over winter. They are hardy but do not like excessive wet. If in doubt, keep them in pots or in bulb baskets where they can be moved into a dry, frost-free place for winter.
Plant in March – April in well-drained soil about 10 – 15cm deep and 10cm apart. Galtonia do well in drier soils that are not too fertile and in warm, sunny borders. They have similar growing requirements to agapanthus and crinum. Mulch well in winter or lift and store in a dry, frost-free place.
Plant in January to March in pots indoors. Gloriosa does best in a warm, humid spot so a warm greenhouse or conservatory is best with support for its climbing habit. Can be grown outdoors in a warm, sheltered place in the South of the UK. Water well once shoots appear and stop when flowering has finished to let the leaves die back and the plant go into dormancy.
Plant in February or March in pots in a greenhouse. Can be planted in the border from May when all frosts have passed. Treat similarly to canna lilies. Water well when growing, stop after flowering in autumn. Mulch well in winter with a dry mulch or bring into a dry, frost-free place. Hedychium does not like it too wet when dormant.
Keep in pots and move to a frost-free position in areas prone to particularly low temperatures and/or a lot of rain, or cover with a bell cloche.
Plant in spring with the neck of the bulb just above the surface of the soil, 15cm apart. Keep moist during the summer and feed with liquid fertiliser. Mulch in water with a dry mulch. Prevent the bulb from getting too wet. Supposedly hardy but mulch or move to a frost free position in the coldest areas if prefered.
Plant bulbs in February or March in pots in a greenhouse, or in late April/May in the border in warm parts of the UK. Mulch well in winter with a thick mulch in warmer parts of the UK or bring into a dry, frost-free place.
Plant in spring at least 7cm deep and 5cm apart. Deadhead regularly and allow the foliage to die down in autumn before mulching in mild areas or lifting in cold areas to store frost-free over winter. Works well in a pot.
Plant about 15cm deep in spring in fertile, well drained and moisture-retentive soil. Feed every couple of weeks during the growing season with a high potash liquid fertiliser, water well, and keep roots shaded by low shrubs or herbaceous plants for best results.
Grit can be added to help drainage, especially if it is wet in winter. Protect from slugs when young.
Plant taller varieties in places sheltered from strong winds. Dead head regularly and cut the stems to the ground in autumn. Many, especially species lilies, will increase each year if undisturbed. They can be very long-lived.
Plant in spring in a sunny, warm spot or in a pot. Mulch well in winter or move pot to a frost-free place. Lycoris is not keen on being moved and may take a year or two to flower after planting.
Whereas nerines can do well if planted about 10cm deep in a sunny, warm spot in milder parts of the UK, mulched well and not subjected to excessive winter wet, it may be safer to keep them in pots and bring them out in late April when all chance of frosts have past.
Plant at least 7cm deep in spring in a warm, sunny border. They may survive overwinter in a sheltered, frost-free position if mulched well. Otherwise keep them in pots and bring them out in late April when all chance of frosts have past.
April-flowering O. dubium is probably the hardiest of them all. I always grow these outdoors with no issues at all but we are in a mild area.
Grow as a pot plant indoors or in a warm greenhouse and re-pot after flowering or lift in the autumn and re pot bulbs in spring. Whilst winter dormant keep completely dry at a temperature between 1 and 5 degrees C – this means in the warmest parts of the UK along southern coasts it may be possible to grow them outdoors, as long as they are kept dry in winter. Water sparingly during flowering but once the roots begin growing (when the leaves will start growing too) start watering normally.
Plant in March – April about 3cm deep and 10cm apart. Some suggest that soaking the tubers for a couple of hours first helps, but they will grow without this. Prefers full sun. Might not be fully hardy in the coldest and wettest areas.
Plant Rocsoea in well-drained but moisture-retentive soil in dappled shade, it does well in light woodland conditions and likes a cool root run. Plant the tubers with at least 4-6 inches of soil above the crown. In cold areas, mulch well for the first couple of winters to make sure the tuber is protected. As it works its way deeper it will be sheltered from summer heat and frost. Lift and divide in April every 3-4 years before growth starts.
Scadoxus can take limited amounts of frost so could be planted out in a sheltered spot in mild areas. Otherwise keep it in a pot and move it somewhere frost-free during the winter. Requires some shade. All parts are poisonous.
Tulbaghia is often advised as half hardy in the UK. However, it is usually exposed positions, excessive wet and sharp frosts that are likely to cause damage. So plant in a warm, sheltered position where the soil does not get too wet.
Keep in pots and move to a frost-free position in areas prone to particularly low temperatures and/or a lot of rain, or cover with a bell cloche.
I had great success with one tulbaghia planted in partial shade under shrubs in a sheltered city garden on light, well draining soil, even when it was covered with 10″ of snow two years in a row.
Watsonia can be planted in a sunny spot in milder parts of the UK and can survive if mulched well. If there is a chance it might be exposed to cold winds, sharp frosts or constantly wet soils, it may be safer to keep them in pots and bring them out in late April when all chance of frosts have past. They will increase where happy.
Plant in a warm, sunny position in the garden and mulch in winter. Not fully hardy in the coldest areas.
Can also be grown on the patio and moved to a frost-free position or grown in a conservatory. Water freely during the growing season.
Alternatively grow in a 20cm pot and water very well (keep the pot in a saucer topped up with water) on a sunny window sill. Once the plant has flowered it will begin dormancy so ease watering until dormant, then start watering again in spring.
Guide to planting spring flowering bulbs
Generally speaking, the later the bulb flowers, the later it can be planted.
Plant bulbs in the autumn, when the weather has cooled and the soil has become damper again after the summer.
Late flowering bulbs can be planted right into January, although September to November is the best time so they can set down roots. They need a cold snap to stimulate flowering.
However, many spring flowering bulbs are tough and forgiving, they can be planted well into spring providing they are still in good condition (by this time you will often see a green shoot). They will flower at the correct time the following spring.
Plant earlier flowering alliums from October to December in a sunny position with fertile, free draining soil. If your soil is very heavy or you live in a colder area, wait until early spring to plant. You can also plant the late-flowering alliums in spring, such as A. sphareocephalon and A. flavum.
Plant large alliums 15cm deep and 15 to 20cm apart, and the smaller ones at 5cm deep and 10cm apart. Alliums will increase each year in good conditions.
Anemone blanda, nemerosa or coronaria de Caen. Soak tubers for at least an hour in cold water before planting. Plant in a sunny to lightly shaded spot, in well-drained, humus rich soil (such as under deciduous trees or shrubs). Plant 5cm deep and 10 to 15cm apart. Ensure they don’t get too much water when dormant in the summer.
Plant in a woodland-type situation, in moisture-retentive, humus-rich soil in dappled sunlight. The bulbs like to be three times as deep as they are tall.
Plant in autumn at 10-15cm deep. Camassia like being damp in spring but don’t mind dry summer soils. Best in full sun. Add grit to heavy or wet soil.
Plant in autumn 5-8cm deep. Plant in closely scattered groups or drifts for best effects. Alternatively plant in pots. If in grass, ensure the leaves have died down before mowing.
Plant in autumn September to November in a sunny, free draining position. Add grit if the soil is heavy or wet. Plant 8-10cm deep and about 5cm apart. If in grass, ensure the leaves have died down before mowing.
Plant in autumn September to the end of November in a sunny, moist but free draining spot. Depth will depend on the size of the bulb, but aim for three times as deep as the height of the bulb. Plant about two bulbs width apart.
Lift and divide dense and overcrowded clumps as this can prevent them from producing flowers. Daffodils often naturalise well.
Plant in autumn in woodland conditions – sunny and moist in spring, cooler and drier in summer – about 5cm deep. Add grit if soil is heavy or wet.
Plant in autumn in well-drained, moisture-retentive soil. Plant tubers about three times as deep as they are tall. Allow to die back in early summer before removing leaves.
Plant in autumn in a sunny position, 5-12cm deep depending on the size of the bulb. Ad grit to wet or heavy soils.
Plant dwarf spring-flowering irises such as I. reticulata in autumn from September to the end of November in a sunny, moist but free draining spot. Plant three times as deep as the height of the bulb and a couple of bulbs width apart. Most should naturalise well and increase each year in good conditions.
Plant at 8cm deep in a sunny position in autumn. Plant in groups or drifts in the border for best effect.
Plant in autumn in well-drained, moisture-retentive soil about 10cm deep. Similar conditions to fritillary but leucojum are often found in woodland conditions as well.
Plant in partial shade in moisture-retentive soil. Lily of the Valley can take a little more sun if the soil is guaranteed damp, it is also happy with more shade and can put up with drier soils if this is the case.
Once established, Lily of the Valley requires little attention. If required, lift and divide after flowering. If grown in a pot, ensure there is enough moisture and if brought indoors for their scented flowers, keep in a cool place out of direct sunlight.
Plant in autumn September to December in a sunny position in well drained soil at about 10cm deep. Most muscari naturalise well and can be lifted and divided in summer when dormant.
Plant in a sheltered position in autumn, with the neck of the bulb not far below the soil surface. Alternatively keep in pots and move to a frost free position in winter. O. dubium is fairly hardy and will usually do well in most of the UK providing the soil is not too wet. O. nutans reportedly less so.
Plant about 7cm deep in a sunny spot in autumn that will be relatively dry during the summer. Plant in groups or drifts for best effect. Add grit to wet or heavy soils.
Plant in autumn, late October to late December when the soil has cooled and preferably after frost which kills soil-borne fungi.
Choose a sunny site with well drained, fertile soil. Add grit if the drainage is not excellent. Plant 10 to 20cm deep and the same distance apart. Planting at least 20cm deep can help tulips come back year after year. They do not like to be too warm during the summer dormancy so planting deep can prevent this. It can also help to support stems of tall varieties.
In less than optimum conditions you may notice that decorative tulips (rather than species) need replacing often as they stop producing flowers.
Tulips can be lifted and stored when the leaves have died down, then replanted the next autumn. Species tulips can be left to naturalise.
Wild tulip, Tulipa sylvestris, doesn’t mind a little shade.