Spring Bulbs: What are they? Are tulips really perennial?
Part One of my new Spring Bulb series
There is something truly magical about flowering bulbs… Take a handful of dry and shrivelled lifeless bulbs, throw them in the ground, wait a few weeks and, like the mythical beanstalk, they burst from the ground with a bounty of beautiful blooms.
Flowering bulbs are more popular than ever and for good reason. The range of species available to us humble home gardeners has increased dramatically. Alongside the species there are a staggering number of bred cultivars with a truly bewildering array of forms and colours. Did you know there are over 3,000 tulip cultivars alone?!
Winter and Spring flowering bulbs, illuminating your borders and pots, bring an early sense of cheer as we slowly meander our way out of winter. Even though they’re tiny, those first snowdrops, cyclamen, aconites, and crocus are worth more than their weight in gold. Loved by us gardeners desperate for life and colour outside those foggy rain-drenched windows. Loved even more by emerging bees, drowsy and famished after winter hibernation.
The miracle of bulbs
Technically, a ‘bulb’ is an umbrella term that covers a range of underground food storage 'organs', They are not seeds. Bulbs differ from seeds, as a seed is an plant embryo inside a seed coat, whereas a bulb is a mass of dense tissue layers, with an immature plant structure within, all wrapped up, flower bud, leaves, and stem. Everything the plant needs is stored in this organ. It is no exaggeration to say the unassuming bulb is a miraculous thing!
But, don’t worry. That’s it for the biology lesson!
There are many shapes and sizes of bulb, from the massive Crown Imperial fritillary through to alliums, tulips, and daffodil (Narcissus), right down to the diminutive muscari, crocus, snowdrops and aconites.
There are 'True bulbs', like allium, narcissus, tulips, hyacinth, and snowdrops. 'Corms', which can look similar to bulbs and include crocuses and gladioli. 'Tubers' are generally brown and gnarly without the flaky skin or tunic and include (wood) anemones and cyclamen. 'Tuberous roots' are swollen roots - just think of dahlias and ranunculus. Lastly there are the 'Rhizomes' which are swollen stems, probably the most recognisable being the Bearded Iris.
On the whole, bulbs are very easy gardening. Essentially, you can buy bags of them (in their dormant state) from nurseries, garden centres and online retailers, or even direct from the growers. The simplest process: Dig a hole, pop them in the ground or in a pot with compost and voila! The following spring, you have flowers! But, to have a great container display, try to buy quality bulbs and quality compost, or make your own if you can. Bulb spacing in pots makes a huge difference, along with punctual planting. There are nuances applicable to each species, but it's fundamentally simple, rewarding gardening.
What are the spring bulbs?
Autumn planted, flowering bulbs are a range of plants that flower from late winter to late spring and on into June. In this category we have the classic spring bloomers: Snowdrops, Crocus, Narcissus, Tulips, and Alliums.
(There is a more comprehensive at the very end)
You can plant any of these bulbs anytime in autumn, even midwinter if the ground isn’t frozen. In the northern hemisphere, I would recommend anytime from October to December. Over winter, the bulbs will initially establish a root system from the basal plate of the bulb, before the shoot emerges from the top. The shoot is surprisingly strong, easily capable of pushing through snow, frosty ground, grit, or gravel. Slowly, the leaves unfurl and the flower stem rises from within.
It really is remarkable!
Buying spring bulbs
Every September or October we order and plant our preferred bulbs, planting them through October to December. In December or January, garden centres and online retailers usually offer discounted clearance bulbs with 50% off! Hard to resist! These need to be planted ASAP! Admittedly, the choice is limited, but they still flower, albeit slightly smaller as they haven't had that time to establish a root system.
Farmer Gracy, Peter Nyssen, and J Parkers (for larger quantities) are all decent suppliers, although we have had a few 'mistakes' from Farmer Gracy. They have refunded the ‘errors’, but it's too late, having already potted them up and waited weeks for those gorgeous apricot tulips, only to find bright, shocking red staring you in the face. (not a fan of the bright reds!)
DutchGrown™ will be supplying almost all spring bulbs for my garden display this season.
I will be creating “How to…” video content for them. DutchGrown™ is a family run business, supplying top-size flower bulbs, and they ship across the UK from their warehouse in London.
Some bulb packet instructions recommend planting from September, but those late summer heatwaves are increasingly more common. Far from the ideal bulb planting conditions. Besides, our beds and borders are still chocked full of plants, all in their late-summer splendour. Trying to plant amongst them would be farcical! I always wait and let nature take its course, letting the border plants succumb to frost. Once they’re cut down and cleared, I have the space and room to plant bulbs, without damaging the perennials. Note: I always leave some standing for food, cover, and winter interest.
Are bulbs perennial?
Almost all spring bulbs are reliably perennial and they will flower year after year, meaning they are a great investment that will steadily grow and spread as they divide and seed about. Although it is worth pointing out that some bulbs like snowdrops, bluebells, and winter aconites actually establish far better when planted ‘in the green’. You buy them in full leaf, normally just after flowering. They are relatively expensive compared to a bag of dried dormant bulbs, but they have a higher success rate.
A good option is to visit local plant fairs in March, where there should be nurseries selling them in bunches. Once they've established, you can lift and divide clumps, moving them around your garden. Alternatively, buy dormant bulbs and plant them up in module trays or 9cm (3in) pots. If and when they successfully grow, plant them out in spring in full leaf.
The one major exception to the perennial question is border tulips. Species tulip are perennial, but those large showy blooms that we all love often fail to reflower (properly) in subsequent years, or if they do, they are often a sorry shadow of their former glory. Read on to discover why...
Tulips! Are they perennial or not?
The ‘species tulips' evolved in the Steppes of Persia and Himalayan foothills, where they experience baking, arid summers and freezing winters, all with sharp drainage. Literally an entire world away from our modest gardens and temperate climates.
Dutch growers overcame those species tulip's ecological necessities by mastering climate control, heat, cold, humidity, plus perfected soils, and irrigation. Contemporary 'border tulips' are grown on an industrial scale, specially bred and hybridised, carefully harvested at their peak. They are primed to survive the first winter in your garden as a fully-fuelled bulb, flowering triumphantly in spring.
However, by the time spring has passed, the fat tulip bulb you planted in autumn has been literally emptied. All that remains are the empty scales and the emergence of a new bulb. Continued bulb and leaf growth is now powered by the established roots. Once the bloom has faded, the leaves power the continued formation of a new bulb and bulblets (aka offsets).
Those poor tulip bulbs are then at the mercy of our 'less than ideal' soils, not to mention the UK's temperate mild and soggy maritime climate, where summers are often damp and winters are ruled by rain and flood, rather than ice and snow. The diminished 'parent bulb' and tiny offsets throw up feeble leaves and an underwhelming bloom, if any. There's a combination of factors at play here:
The 'species tulip' genetic environmental adaptations.
Contemporary breeding and hybridising.
The vastly different growing conditions in gardens.
The natural lifecycle of the tulip bulb.
In a perfect world, those little offsets would build and 'recharge' over the years, forming another garden-worthy bulb and sometimes they will. If you have cold dry winters and well-drained or sandy soil you may well find tulips are perennial as it's closer to their ideal habitat.
Understandably, the lack of reliability means that many gardeners simply treat tulips as annuals and after that first fancy bloom, they are unceremoniously ripped out and tossed onto the compost heap. Honestly, it seems a real waste considering both the financial price and environmental cost of buying them and growing them industrially.
I fully appreciate that our gardens are all different with varying factors of soil, aspect, macro-environments, and climate. I know gardeners that have planted tulips decades ago and that are still flowering to this day. There is no one rule, but for many, tulips can be unreliable.
The good news…
There are particular tulip cultivars that are recognised as being more perennial than others. Darwin hybrids, Fosteriana tulips like ‘Purissima’, and Viridiflora tulips like ‘Spring Green’ are all said to be ‘more perennial’. There are also tips and tricks you can try to get your tulips to bloom more reliably:
Plant tulip bulbs extra deep. In many gardens, the deeper soil is drier and the added depth seems to inhibit the creation of smaller offsets.
Avoid watering too much and once the leaves yellow, stop watering altogether.
Avoid planting them in any ground that is liable to waterlogging. Remember, tulips want sun and good drainage! Excess water is the enemy!
Deadhead tulips immediately as soon as the petals start to fall. This conserves the plant's energy, redirecting it back into to the bulb. This is a good time to feed tulips with liquid seaweed as they enter their regeneration cycle.
Summer warmth is good! Tulip bulbs need warmth during dormancy as the new flower forms within. Well drained soil warms quicker than wet soil. Even more reason to plant in well drained soil, raised beds, or gritty sharp-draining potting compost.
My very unscientific tulip trial
In 2021, after the usual massive Garden Terrace display of spring bulbs, I planted-out all the spent tulips 'in the green' as an experiment. They were all planted into the Flower Garden borders, in clumps, just as they were in their various pots and planters. In Spring 2022, the vast majority of tulips returned, some just as beautiful as the year before, others significantly diminished. Over the following two seasons, many tulips have continued to fade away, but these have remained: Daydream, Negrita, Greenstar, White Triumphator, Sapporo, Mistress, Ballerina, Princess Irene, Angelique.
Of these tulips, Daydream, Negrita, Greenstar, White Triumphator, Ballerina have remained especially strong. White Triumphator, Ballerina and Daydream are particularly noteworthy. As beautiful and as vigorous now as when they were first planted! The caveat, of course, is that my soil and aspect will be different to yours.
I hope you found this useful! Thank you for reading. It is always appreciated!
Best wishes and happy gardening!
Elliott
Coming up… How do you plant bulbs in pots?
Spring bulbs worth considering...
Galanthus (Snowdrop) 🌱 🐝
Eranthis hyemali (Winter Aconite) 🌱 🐝
Crocus 🐝
Scilla
Chionodoxa (Glory of the snow)
Iris reticulata 🐝
Iris × hollandica
Narcissus (Daffodil)
Muscari (Grape Hyacinth) 🐝
Hyacinthoides (Bluebell) 🌱 🐝
Hyacinth
Tulipa spp (Tulip) ➕🐝
Fritillaria ➕ 🐝
Camassia 🐝
Allium ➕ 🐝
Convallaria majalis (Lily of the valley) 🌱
Allium siculum (Sicilian honey garlic) 🐝
🌱 Establish best when planted in the green.
➕ Wide range of cultivars with different plant heights and overall sizes.
🐝 Flowering bulbs favoured by bumblebees.