By ELIZABETH WADDINGTON Elizabeth Waddington, MA, Dip.Perm.Des. - Garden Designer Elizabeth is a Permaculture Garden Designer, Sustainability Consultant and Professional Writer, working as an advocate for positive change. She graduated from the University of St. Andrews with an MA in English and Philosophy and obtained a Diploma in Applied Permaculture Design from the Permaculture Association. Roy Nicol, MHort (RHS), MCIHort - Horticulturist Roy is a Professional Gardener and Horticultural Consultant, specialising in large garden year-round maintenance and garden development. He is an RHS Master of Horticulture and uses his research in the application of no-dig methods in ornamental garden settings. Roy has been a Professional Gardener for more than six years and is a member of the Chartered Institute of Horticulture, Professional Gardener's Guild and Association of Professional Landscapers (Professional Gardener). BULBi BULBi is an online supplier of a huge array (more than 170 varieties) of bulbs and tubers here in the UK. Jonathan has worked in the industry for as long as he can remember. He’s previously grown gold-medal winning lilies for displays at various flower shows throughout the UK, including at the prestigious RHS Chelsea Flower Show each year, where his nursery has recently been awarded the EH Trophy for their exhibit of cut flowers. 
Reviewed By ROY NICOL 
Contributions From BULBi 
IN THIS GUIDE
- Types Of Bulbs
- When To Plant Bulbs
- How To Plant Bulbs
- Lasagne Planting
- What If You’ve Missed The Right Time For Planting?
- FAQs
Bulbs of many types can be useful and beautiful additions to a garden.
In this guide, we’ll explore some different options, and help you understand when and how to plant them.
We worked with the team at BULBi, Jonathan Hart from Harts Nursery and RHS Master of Horticulture Roy Nicol to curate some useful tips and tricks in this guide.
“Flower bulbs are a gardener’s best friend. They are easy to plant, low maintenance, and provide year-round interest in the garden.
“Whether you are a seasoned gardener or just starting out, flower bulbs are an excellent choice for adding colour, texture, and beauty to your outdoor space.”
For those beginner gardeners: ‘Bulbs’ is a term used in gardening to refer to bulbous plants – herbaceous perennials grown for ornamental or edible purposes which have underground (or near-ground) storage organs, used to store water and plant nutrients during dormancy.
“What makes us so passionate about growing bulbs is seeing how something so beautiful can come from them,” Jonathan says.
“The promise and suspense of planting a bulb is something that always excites us.”
There are so many types of bulbs, tubers, corms and rhizomes so there is always something to suit everyone’s taste.
“It’s always amazing to see the first sign of spring bulbs coming through to let us know good things are coming.”
Types Of Bulbs
While we refer to these plants as ‘bulbs’ colloquially, botanists will distinguish between true bulbs, rhizomes, tubers, corms and tuberous roots.
In horticulture, it is beneficial to categorise bulbs into:
- Spring-flowering ornamental bulbs.
- Hardy summer-flowering ornamental bulbs.
- Edible bulbs treated as annuals in a vegetable garden.
- Perennial edible bulbs.
- Tender summer-flowering ornamental bulbs.
- Autumn flowering bulbs.
When To Plant Bulbs
“We always say that spring-flowering bulbs (such as daffodils, tulips, hyacinths, crocuses, etc.) should be planted in autumn,” says the team at BULBi.
“However, the soil should be well-cooled, as the bulbs need a cold period under the soil – so planting before September is definitely not the perfect time.
“Of course, this also depends on the climate where you live, but ideally you should plant the bulbs in autumn, and October or November is early enough.
“The flower bulbs can even still go into the ground in December – but then it shouldn’t be freezing.”
Hardy flowering ornamental bulbs that bloom in the summer (like ornamental alliums, crocosmia and lilies) can also be planted in autumn.
“Although Crocosmia and lilies are really summer bloomers and we always recommend planting them in spring.” says BULBi.
Autumn is also the best time to plant perennial alliums like elephant garlic.
Tulips, which flower a little later in spring should be planted later in autumn, in November.
Tender summer-flowering bulbs like gladioli are best planted from March to April.
Autumn-flowering bulbs, like nerines, for instance, should be planted before the end of the summer.
How To Plant Bulbs
Bulbs should be planted out as soon after they are acquired as possible.
Your first decision will be where you will place your bulbs, which varieties will be appropriate for your desires or requirements, and the location.
“The versatility of flower bulbs is one of their biggest selling points,” shares the team at BULBi.
“They can be grown in a variety of conditions, from full sun to deep shade, making them a great option for any type of garden.
“With a little effort and planning, you can have a garden filled with beautiful flowers from early spring through late summer.”
You might place bulbs:
- In borders or beds.
- In fruit tree guilds or other polycultures.
- In containers.
- In lawns and long grass.
“Always make sure you check that you are planting your bulbs in the correct position,” says Jonathan Hart.
How deep bulbs should be planted depends on which specific bulb you have chosen to grow.
However, as a general rule of thumb, it can be helpful to work from the guideline that bulbs should be placed at a depth of around 3 times their height.
“If it’s your first time planting bulbs go for something that needs little care like tulips, alliums or narcissi,” Jonathan suggests.
“Also, don’t be afraid to try something that looks exotic.
“Lilies, for example, are some of the hardiest bulbs you can plant and can actually withstand temperatures of -20°C, so our UK climate is fine for them.”
In Borders & Flowerbeds
If planting bulbs in borders or beds (in soil that has been prepared for the bulbs you want to grow) you should consider the tips outlined below.
Make holes deep and wide enough to accommodate each bulb.
For a bulb that is 3cm high, dig a hole around 9cm deep and sit the bulb at the base of it.
As a general rule of thumb, bulbs should be spaced around twice their own width apart from one another, so, for example, bulbs that are 5cm wide should be placed roughly 10cm apart.
For pleasing displays of ornamental bulbs in beds and borders, aim to plant in groups of 5-10 – larger drifts of bulbs can look better, so often, you’ll need 50 bulbs, or even more, to make an impact.
Usually, bulbs will have a pointier end from which the shoot will grow, and this should be placed facing upwards, as the experts at BULBi explain:
“You can hardly go wrong with planting bulbs. Did you know that flower bulbs grow towards the light? We always plant them with the tip upwards and the flat side down because that’s where the roots grow in the earth.
“However, even if the flower bulb is crooked, that’s no problem. The flower will just grow out of the earth.”
Bulbs can be fairly closely placed along the borders of a fruit tree guild or another planting scheme to reduce grass/weed ingress into the growing area.
Alliums (both edible and ornamental) can be useful additions for a range of reasons in an organic garden and can often help in organic pest control.
Bulbs planted on a sloping area can be beneficial in stopping runoff and nutrient losses.
Once bulbs have been planted into the soil of the growing area, soil should be gently firmed back over the site.
Avoid stepping on the soil since this can damage the bulbs, as well as causing compaction.
When planting in autumn, or when the soil is sufficiently moist, watering-in may not be required.
However, for spring and summer plantings, when the soil may be dry, water straight after planting.
Add an organic mulch to maintain fertility, protect the soil, reduce weeds and conserve soil moisture.
A mulch of autumn leaves or similar can also help keep overwintering onions or garlic and other bulbs safe over the winter months.
In Containers
Many ornamental and edible bulbs work very well in containers.
The containers should allow for good drainage while retaining sufficient moisture for the bulbs in question.
The growing medium used should be chosen for the specific bulbs you wish to grow.
The mix should be different depending on whether the bulbs will remain in the container only for a single season, or will be in the container longer term.
“As not all bulbs like the same aspect or if you have a heavy clay garden, we would suggest planting your bulbs in nice pots or containers,” says Jonathan.
Bulbs in containers can typically be placed with one bulb width between them.
After planting up containers, it can, again, be beneficial to place an organic mulch on top – sometimes, you might also consider a decorative gravel mulch or similar.
When planting in autumn, a mesh cover might be used over the top to prevent squirrels from unearthing your bulbs and undoing your good work.
Bulbs in containers will usually have to be watered more frequently than those in the ground.
Water after planting, then regularly while the bulbs are in active growth, then taper down watering during dormancy but make sure pots do not dry out altogether.
For best results, feed bulbs in a container every week or so with a high-potassium organic liquid plant feed.
This should be done from the time when the first shoots emerge to when the foliage begins to die down as the plants move towards dormancy.
In Lawns & Long Grass
Many bulbs can also look beautiful and perform well when naturalised in lawns or taller grass.
To naturalise bulbs in grass you should throw bulbs from waist height and let them naturally fall where they may.
Then, plant them exactly where they fall for a naturalistic look.
Planting holes can be dug with a trowel, but using a bulb planter will make things quicker and easier when planting through the turf.
Place the bulbs and crumble some soil from the plug you have taken out around the bulb to backfill.
Then replace the plug of turf on top, trying to keep it at the same level as the surrounding area.
Lasagne Planting
When planting bulbs, it is important to think not only about one variety in isolation.
Often, the most impressive results can be achieved by planting multiple types of bulbs.
A type of layered planting called ‘lasagna planting’ is a strategy used to plant more than one bulb type in a particular growing area and thereby extend the flowering period.
What If You’ve Missed The Right Time For Planting?
Bulbs are not like seeds and cannot last out of the ground or a suitable growing medium for long.
While many seeds will still be viable if you wait a year, storing them in a suitable environment before planting the following year, bulbs usually lose viability more quickly.
If you forget to plant bulbs in autumn, or couldn’t plant as planned, don’t try to wait until spring or autumn the following year.
Bulbs are likely to rot, turn soft, or deteriorate further.
Some store longer than others, and how long bulbs will still be in good condition will also very much depend on where they were kept, but generally, it is best to go for it as soon as possible – even if you missed the optimal planting time.
Get your bulbs into the ground or into containers as soon as you possibly can – after checking them over and discarding any that are soft or rotten.
Late is better than never.
Planting bulbs late will usually mean that they will not perform as well during their first year, but if they are a type which returns year after year, they should gradually get better over time.
FAQs
Should You Soak Bulbs Before Planting?
While soaking bulbs before planting is not necessary, it can bring benefits for certain bulbs.
Soaking bulbs, corms or tubers in tepid water for a while before planting will hydrate them, making sure they have the water they need to develop.
This can lead to quicker growth and potentially earlier flowering for a certain few bulbs.
“Flower bulbs (such as tulips, daffodils, hyacinths, muscari, crocus and all other spring-flowering bulbs), do not need to be placed in water,” argues the team at BULBi.
“In fact, that is bad for the flower bulb, the bulb will rot.
“Even if you water these flower bulbs (which is not really necessary because they get enough water in autumn and they have enough nutrition), it is very important that the water can drain away properly – so that no excess water can remain.
“A pot should therefore always have a hole in the bottom.
“Anemone tubers and ranunculus corms can be put in water for a while before planting.”
How Many Bulbs Can You Plant Together?
How many bulbs you can plant together very much depends on:
- Where you live and the specifics of the place where you are planting.
- The type(s) of bulbs you are growing.
- The space you have available.
- Other plants growing in the area.
Do Bulbs Come Back Every Year?
BULBi shares how only the naturalising varieties of bulbs return the following season.
“These include daffodils, crocuses, galanthus, muscari and hyacinths.
“In general, tulips are also annual bloomers. Tulip bulbs usually flower for one year once they are planted in the garden.
“In their first year, they produce beautiful flowers; in their second year, you will only see a few green leaves; and in their third year, you will probably see nothing at all.
“In the flower bulb fields, tulip bulbs are also harvested after one flowering period. As soon as the tulips bloom, they are cut off, which we call deadheading.
“The nutrition then all goes to the bulb. When the remaining leaves have turned yellow, the bulbs are lifted.
“After lifting, the bulbs are cleaned and stored dry. After which they are returned to the ground in autumn.
However, there are tulip varieties that you can leave in the ground, and which will return the following year. We call these perennial tulips.”
