The Complete Guide to Planting Bulbs — step-by-step

Flower bulbs offer years of blooms. And whether you leave them in the ground or dig them up to  store them over the winter, if you treat bulbs right, they offer decades of beautiful spring, summer, autumn, and winter blooms. 

And while some bulbs are super-hardy, others struggle to survive. So, it’s essential to understand your bulbs’ needs so that these gardeners favourites burst into flower for years to come.  

In this article, we’ll explore everything you need to know about planting bulbs. 

What are the types of flower bulbs?

A flower bulb is a swollen underground tuber that produces a flowering stem. There are several approaches to planting bulls, depending on the variety and your garden’s conditions. 

Some of the most common bulb plants include:

• Daffodils
• Tulips
• Hyacinths, 
• Lilies
• Gladioli
• Begonia

Spring-flowering bulbs include:

• Daffodils, with their beautiful yellow, white or pink flowers
• Tulips, in a wide range of colours
• Hyacinths, offering grape-like fragrant springs bloomers in all kinds of bright colours

Summer-flowering bulbs include:

• Lilies, offering graceful, fragrant flowers
• Gladioli, producing tall, large, showy flowers
• Begonias, with a rich variety of colours and patterns.

Autumn— and winter-flowering bulbs include:

• Crocuses, producing vibrant purple, white, or yellow blooms
• Dahlia, bursting into star-like flowers in a vast range of colours
• Cyclamen hederifolium, with its unusual, upside-down flowers and silvery, marbled leaves
• Begonia, for tons of orange-tinged yellow flowers
• Snowdrop, with its drooping, long-petaled blooms
• Winter Aconite, bringing the sunshiney yellow to your winter garden. 

Are all bulbs the same?

No. A bulb is an underground food-storage organ, and there are four types:

• True bulbs — typically rounded at the top, with a flat root base. Examples are daffodils, snowdrops, and lilies. 
• Corms — similar looking to bulls, but they have one or two buds at the top. Examples are crocuses and gladioli.
• Tubers — rather than true bulbs, these are actually swollen roots (as in dahlias) or swollen stem bases ( as in cyclamen)
• Rhizomes — swollen stems that grow just below the surface of the soil or horizontally. Examples are lily-of-the-valley, cannas, and bearded irises. 

While these bulb types look different, they play a very similar function, i.e., to store food during its active phase for the plant’s dormancy.

Planting bulbs — where’s best?

Plant flower bulbs directly into the ground or add them to pots. 

Planting bulbs in the ground

When planting bulbs in the ground, choose a sunny spot with plenty of direct sun. Dig a hole deep enough to cover the bulb and its roots completely. Ensure the soil drains well — it should be moist, not wet. 

Mix compost, mulch, or well-rotted manure into the soil to improve drainage if needed. 

Planting bulbs in pots

If you’re planting bulbs into pots, ensure you give them plenty of space to establish — don’t overload the pot. 

Make sure the pot drains well; otherwise, your bulbs could rot. 

Planting bulbs — when?

When to plant your bulbs depends on when they will burst into flower.

• Spring-blooming bulbs — plant them in late autumn when the soil temperature has cooled.
• Summer-blooming bulbs — plant them in early spring after the risk of frost has passed.
• Autumn and winter-blooming bulbs — plant them in late spring. 

Planting bulbs — how deep?

Bulbs differ in size and shape — but the general rule is:

Plant your true bulbs at a depth of two-to-three times their height.

So, if a bulb is 2cm from the top to the bottom, plant it 4-6cm deep. You don’t need to plant bulbs quite so deeply in pots. 

Plant rhizomes just below the soil’s surface and tubers around 15-20cm deep. However, you can plant stem tubers, such as cyclamen, near the surface — always check the instructions on the packet. 

Ensure that the soil isn’t too wet when you plant them, or they could rot. On the other hand, water the soil well after planting if the soil’s dry.   

How far apart should you plant bulbs?

Overcrowding your soil with flowering bulbs won’t necessarily result in more blooms. The rule of thumb here is:

Leave at least three times the bulb’s diameter between each bulb. 

So, if a bulb is 2cm wide, leave at least 6cm between each bulb. 

A Calendar of blooms — when your bulbs will flower

It’s possible to enjoy flowering bulbs all year round — you just need the right mix. So, here’s a handy overview of the year’s blooming bulbs.

• January to February: snowdrops, winter aconite
• February to March: crocus, spring bellflower
• March to April: daffodil, star hyacinth.
• April: hyacinth, blue grape
• April to May: lapwing egg, tulip, summer snowflake.
• May: lily of the valley.
• May to June: bluebell
• June to August: lilies
• June to September: Gladiolus
• June to October: begonias
• November to December: Nerines, Amaryllis, Paperwhite narcissi

A step-by-step guide to planting bulbs

Planting bulbs is fairly straightforward. You’ll need a hand-held potting spade if you’re planting individual bulbs or a well-prepared flower bed if you’re planting lots of bulbs in the same place.

1. Find the ideal location: a sunny spot is preferable, although check the bulb packet; some bulbs do well in dappled- or full shade.
2. Loosen the soil well with a spade, ensuring the texture is crumbly and not too wet. Mix mulch, compost, or well-rotted manure if the soil is too wet. 
3. Dig a hole deep enough for your flower bulbs (following the guidance in the previous section). Use a spade or bulb planter. 
4. Plant the flower bulb in the prepared hole with the pointy end facing upwards and the root end down into the earth. 
5. Cover the bulb with soil and press it down lightly. 
6. Water thoroughly. 

Simple! There’s very little to it! Follow these guidelines, and you’ll be enjoying flowering bulbs all year round. 

Care and maintenance of flower bulbs

Hardy bulbs require very little maintenance, especially if growing in the ground. 

Watering your bulbs

You may need to water the soil during drought; otherwise, hardy bulbs are pretty straightforward in terms of care. 

You may need to water potted bulbs because the soil is more likely to dry out, especially in warm conditions. 

Bulbs need extra water while they’re growing and for six weeks after the flowers have died down. Once the green leaves have died, they’ll become dormant until the next growing season. 

However, you need to regularly water summer-flowering tubers and rhizomes that produce lots of blooms, such as dahlias and cannas.

Feeding you bulbs

Depending on the bulb variety, feed your bulbs at least once a year with an appropriate fertiliser. It’s always a good idea to keep the bulb packet for later reference. 

Most bulbs benefit from a high-potassium fertiliser — so tomato feed could do the trick! Feed as soon as the shoots emerge from the ground, and stop when the foliage is dying down. 

Potted bulbs need a feed before they burst into flower and continue until the foliage goes yellow. 

Feed vigorous tubers and rhizomes that produce lots of blooms fortnightly using a high-potash feed. 

Should I deadhead my bulbs?

Once the flowers have died, it’s best to cut spent flowers at the base of the flower stalk. And while this won’t necessarily stimulate new flower growth, it will help return energy to the bulb for the following year. 

However, deadheading tubers and rhizomes encourages further flowering. 

How to overwinter your bulb

Leave hardy bulbs in the ground during the winter, although you might want to put your pots in your greenhouse to protect them from hard frost. 

You can transfer half-hardy flowering bulbs, such as dahlias, gladioli, agapanthus, and cannas, into pots and bring them indoors over the winter. But this isn’t necessary for warmer regions of the UK — just cover the growing area with 25cm of mulch to insulate the soil instead. 

However, heavy clay soil retains its moisture for too long and can cause half-hardy and borderline-hardy bulbs to rot, so these should be lifted and allowed to dry out over winter (or placed into a pot and brought inside). 

How to lift bulbs after flowering

Some bulbs are better dry and in storage after they’ve gone dormant, such as tulips. So, lift and dry them, and store them in a cool, dry place until autumn when you can replant them. 

To life corms and true bulbs:

• Dig them up once the foliage has died down. Loosen the soil from the body of the bulb. 
• Trim the roots and remove flaking layers.
• Lay the lifted bulbs on a tray to dry out — wait for at least one day. This will help prevent fungus. 
• Place the dried bulbs in labelled nets or paper bags — store them in a dry, cool place. 

FAQs

Conclusion

Planting bulbs can be a great way to add a splash of colour and life to any garden. For the best results, it is essential to know when, where and how to plant them.

In this blog post, we’ve covered all the details you need to get the most out of your bulbs, from the different types of bulbs to the months they bloom. 

If you follow the tips in this article, you’ll get the most out of your flower bulbs and enjoy a beautiful garden for years to come.

Thanks for reading!