Tips for Planting Bulbs: A Gardener’s Guide

Planting bulbs is usually a fairly straight forward gardening task but it requires a little vision and a little patience: you need to imagine how the flowers will look when they finally bloom and you have to wait for them to do that!  But, whether you’re after vibrant spring tulips, fragrant summer lilies or autumn-flowering crocus, bulbs add bursts of colour and life to your garden with relatively little fuss. And the best part?  With a little know-how, there are bulbs to plant at virtually any time of year to keep your garden blooming across the seasons.

Here are some practical tips to help you get the most from your bulb planting, whenever you choose to do it.

 

1. Know Your Bulbs: When to Plant What

The first step is understanding the type of bulbs you’re dealing with, as they need planting well ahead of their flowering season in order to have established in time. Bulbs generally fall into three categories:

Let’s start with spring-flowering bulbs – and there are so many of them!

Snowdrops, Iris reticulata, crocus, grape hyacinth (Muscari), narcissi (daffodils), hyacinths, crown imperial (Fritillaria imperialis), snakeshead fritillary (Fritillaria meleagris), alliums and camassia will appreciate being planted in September or October.

Crocus, daffodils, grape hyacinth (Muscari), tulips, crown imperial (Fritillaria imperialis), camassia will prefer being in the ground in November and tulips should, ideally, be held off until December.

Summer-flowering bulbs, including nerines, lilies, gladioli, dahlias, cannas, crocosmia, eucomis, anemoe and begonia. These should be planted in April and May, after the danger of frost has passed, to bloom later in the summer. 

Autumn-flowering bulbs like colchicums or autumn crocus. These are planted in late summer to early autumn, ideally around the end of August.

While there are ideal planting windows, many bulbs can still be planted outside these times, with some extra care.  I’ve bought tulips in the January sales before now and still had some lovely blooms from them, although admittedly a little later than they might have flowered usually.

2. Know Your Bulbs: Where to Plant What

Healthy bulbs start with healthy soil. Most bulbs prefer well-draining soil rich in organic matter. If your soil tends to be heavy clay or waterlogged, consider digging in some grit or compost to improve drainage.  If your soil is sandy and drains too quickly, again, think about digging in some compost or well-rotted manure to help hold on to just enough moisture.

Most bulbs prefer a sunny location and good air flow, so pick a suitable spot for them.  However, some bulbs, particularly early spring-flowering ones that naturally grow in woodlands, can tolerate shade quite well and perhaps slightly more moisture.  For a damper, shady spot, you might like to try snowdrops, crocus, scilla, bluebells, lily of the valley, Chionodoxa or grape hyacinths.

Before planting your bulbs, loosen the soil to at least twice the depth of the bulb. This encourages strong root growth and helps water reach the bulb without pooling around it.

 

3. Give Them Space (and Depth)

A handy rule of thumb for planting depth is to plant bulbs about two to three times as deep as their height. For example, if a tulip bulb is 5cm tall, plant it to allow around 10-15cm of soil above it. Planting at the right depth protects bulbs from frost and encourages healthy growth.  It also helps to ‘anchor’ showier flowers – like the big blooms of gladioli – better in the soil.

Give bulbs a little breathing room and space them out to allow them to clump up as they mature.  Again as a rule of thumb, aim to plant them at least twice their diameter apart.  For a higher impact display more quickly, you can plant them just one diameter apart but be aware that you may be digging them up and moving them if they clump up quickly.  And crowded bulbs may bloom less vigorously and be more prone to disease than those with more room to breath.

4. Planting at Any Time: What to Keep in Mind

Whether you’re planting spring bulbs now or any bulb outside its preferred planting season, here are some general tips to bear in mind.

Forced bulbs: You can plant bulbs indoors in pots anytime for “forcing” blooms on your windowsill. Crocus, miniature daffodils and hyacinths work well this way, and we’re probably all tried to flower an amaryllis in time for Christmas, with varying degrees of success!  You need to work with their natural flowering cycle in terms of light, temperature, food and water to get them to flower out of season. They may need a chilling period in the fridge or a cold spot before flowering, for example.

Late planting: If you’re planting spring bulbs late (say in late winter or early spring), choose larger bulbs and plant them a little deeper to compensate for shorter root development time.

Summer bulbs: Plant summer-flowering bulbs as soon as the soil warms. If you’re late, potting them up and keeping in a warm, sheltered spot can help ‘catch them up’.

Autumn bulbs: If you miss the window for autumn bulbs, try planting them in pots indoors first to get them going, then move outside when the weather cools.

 

5. Watering and Feeding

Once you’ve planted them, it’s easy to forget them until you see their green shoots appear but they will still need some attention before that happens.  As with all plants, water bulbs well to settle the soil around them immediately you’ve planted them.  Then, during dry spells, keep the soil around them moist but not waterlogged.

In their growing season, you can give them a nutrient boost with a balanced fertiliser or a little organic feed like seaweed or compost tea. Avoid high-nitrogen feeds, which encourage leafy growth but fewer flowers.  If you want to have a good display for several years, don’t neglect them after the flowers have finished as this is the time when the bulb is replenishing itself ready for the next season’s growth.

 

6. Protecting Your Bulbs

Bulbs can attract pests like squirrels, rats or even deer. To protect the, consider wire mesh or netting to deter persistent diggers or mulch with a layer of bark or leaf mould to help insulate them and discourage pests.   Deer and rodents aren’t keen on daffodils so you may find mixing some daffs in with more ‘vulnerable’ and tasty bulbs help put them off, too.

7. After Flowering Care

Don’t cut back the leaves straight away! Let the foliage die back naturally as it helps feed the bulb for next year’s growth. Once the leaves turn yellow and wither, you can trim them down.

If you’re growing bulbs in pots, you can lift and store them after flowering if needed, but in the garden, most bulbs thrive best left undisturbed for a few years.

 

Potted Summary

Planting bulbs isn’t just an autumn chore; with the right knowledge, you can enjoy the process and rewards all year round. Understanding your bulb types, preparing your soil, planting at the right depth and giving your bulbs a little extra care can lead to glorious displays season after season.

So go on, get your hands dirty and start planning your bulb strategy – your garden will thank you for it!