How to grow Spring Flowering Bulbs

Spring-flowering bulbs need to be planted during autumn and, together with spring bedding, they make a colourful early display. Bulbs (underground storage organs) require very little care, many can simply be planted in autumn allowing you to sit back and wait to enjoy the rewards in early spring year after year! You might come across the terms ‘corms’, ‘tubers’ and ‘rhizomes’ as well. They are all words given to underground storage organs of different plant varieties, but they behave more or less like bulbs.

 

When they Arrive

Your bulbs will be delivered to you in the autumn, which is the best time to plant them. To ensure you get the most flowers from your bulbs, they should be planted while they're fresh and in good condition. The longer they're stored, the more of a chance there'll be that some might fail or rot. But if you can't plant your bulbs straight away or you would like to store them, it's best to give them a dry, frost-free environment wrapped in paper or loose in a cardboard or wooden box or something breathable (not plastic).

Your plants are supplied as either bulbs, tubers, corms or rhizomes.

Bulbs - (Daffodils, Tulips, Hyacinths etc.) Typical bulb shape, some have fleshy scales. The under-side of the bulb has visible roots.
Tubers - Tubers are a thick, fleshy underground stem/root. Sometimes they have fine roots attached and small visible buds. More common in summer flowering varieties (such as Dahlia).
Corms - (Anemone, Crocus, Aconite etc.) Some are large, round and quite flat in shape and other are very small and look more like little brown 'nuggets'. In large corms, it's possible to see which is the top side and which is the bottom and should be planted with the concave side facing downwards and the convex side facing upwards.
Rhizomes - (Iris germanica) A thick root with enlarged, bulbous nodules. Rhizomes should be planted horizontally, semi-submerged in the soil so that the top half is exposed to the sun.

 

Before Planting

Bulbs prefer free-draining soil. For best results, dig in some coarse sand or grit before planting to aid drainage if soil is heavy or compacted. To give your plants an extra boost and to maximise flowering, rake some fish, blood and bone or Organic Extra dry Farmyard Manure into the surface of the soil before planting. For a natural look, why not plant some daffodils or snowdrops to emerge from a bit of your lawn. Before planting the bulbs scatter them onto the lawn to see where they land. By scattering the bulbs you’ll create a more natural-looking effect, than if you were to position the bulbs one by one.

 

Planting

Autumn is the time to think about planting bulbs. They will start to flower next spring and cheer up our gardens from early spring into summer. Whether you choose traditional favourite bulbs such as daffodils, tulips, hyacinths, and crocuses, or more unusual bulbs such as jewel-like chionodoxa, you won’t be disappointed; they’re cheery, colourful and reliable. When you are planting in a container or in open ground, aim to plant at a depth 3 times the height of the bulb or, if a long flattish tuber, 3 times the height when laid flat. Bulbs prefer free-draining soil. Digging about a week before planting and adding some coarse sand or grit will aid drainage if soil is heavy or compacted. Dig a hole to the correct depth for the variety of bulb. (3 times the height of the bulb as a general rule of thumb.) Loosen the soil in the base of the hole, if it is heavy clay add a cushioning layer of coarse sand or grit to the bottom, and place the bulb on top. Ensure the bulb is the right way up. Mix the soil with some compost and backfill the hole, firming the soil gently to ensure there are no air pockets.

Planting Bulbs - Dig a hole with a trowel 2 – 3 times the depth of the bulb. Loosen the soil at the bottom of the hole. If your soil is very heavy or clay, mix in a good handful of grit or sand too. Position the bulb at the bottom of the hole in an upright position (with the pointed end facing upwards)and backfill the soil. Spacing: This depends on the height of the bulb, however it doesn't matter it they're planted closely together because over the years they will naturalise in their position anyway. Many bulbs grow upright and don't have a wide spread, this means it's best to just plant your bulbs wherever you want them to pop up. 

Planting Tubers - The tuber should be planted horizontally with the old stem at the top, so dig a hole that’s wide enough to accommodate it and about 5in/12cm deep. Loosen the soil at the bottom of the hole. If your soil is very heavy or clay, mix in a good handful of grit or sand too. Position the tuber at the bottom of the hole. Position the bulb with any visible buds pointing upwards. Backfill the hole and firm down with your hands. Water thoroughly after planting.

Planting Rhizomes - The rhizomes should be planted horizontally and very shallowly, with only half the width submerged so the other half is exposed to the sun. With a trowel, make a hole the same width as the horizontal rhizome and sit the rhizome on top. Backfill the soil and firm down, ensuring the rhizome is exposed through the soil surface. Water-in after planting. 

Planting Corms - Corms are planted close to the surface. Larger corms can often be seen partially emerging from the soil surface. For large corms it’s important to ensure the bulb is positioned the right way up. The concave side of the corm should be facing upwards. Cover the corm with a fine layer of soil – the edges of the corm should only just be visible. For very small corms it's very difficult to tell whether there's an up or down-side. These will be fine if planted either way up. 2cm below the soil surface is enough for many types.

 

Planting in containers

Planting in containers allows you to extend the flowering area of your garden, and allows you to grow flowers on a balcony, if indeed you don’t have a garden. You can create lovely displays by growing bulbs in a collection of containers all grouped together. When planting, ensure the container has good drainage holes. Place broken crocks or polystyrene in the base of the pot but make sure you don’t block the drainage holes. Crocks positioned randomly within the container soil will further aid drainage. Be aware of sharp edges though and wear gloves when emptying the soil at a later date.
Half fill with compost and place bulbs on top. Cover bulbs, firm compost gently, and water well. Label with date and variety to keep track.

 

Season-long container displays

If you want to add floral interest in autumn and winter while you’re waiting for the spring-flowering bulbs to come up, plant colour-coordinating pansies and violas. You’re spoilt for choice now on the colour ranges. Plant with bellis, primroses and decorative ivy to cheer you up in the winter months.
If you want a spring to summer season long display plant a number of bulbs in one container so that the flowers come up in stages. Plant snowdrops and aconites for February, followed by narcissi for March, daffodils for April and tulips for May. Layer like a lasagne! Place tulips bulbs on the bottom layer. Cover with compost. Follow with a layer of daffodils bulbs. Repeat. You can furnish the final layer with small bulbs like narcissi, snowdrops, chionodoxa and grape hyacinths. Place a layer of decorative stones on top of the container, to create an attractive finish. Slugs are less likely to cross a sea of stones than they are bare soil. An added bonus.

 

Planting Indoor Bulbs

Fill a pot with compost leaving just enough space at the top to sit the bulb, with the top of the bulb level with the rim of the pot. Sit the bulb on top of the compost with the pointed-end facing upwards.
Fill around the bulb with more compost until it reaches approximately 1cm from the rim of the pot, leaving the top of the bulb exposed, and firm down. Water-in after planting and position in a light, draft-free place in the home.

 

After Flowering

After your bulbs have finished flowering it's tempting to cut the leaves back to neaten the area. However it's best not to do this. As long as the leaves are still green they should be left intact as they will be providing energy to the bulb so that it can grow back next year. Once the leaves have turned yellow they can be cut down to the base. If you wish to relocate your bulbs, this is best done just after the flowers have finished and while the leaves are still green. If lifting bulbs to store, keep them in a light, dry, frost and draft free place to plant again the following autumn. 

 

BULB SPACINGS TABLE AND VARIETY INFORMATION

Bulb Spacings Table