How to Naturalise Bulbs
One of nature’s most beautiful spring spectaculars has to be the drifts of bulbs which create carpets of colour in woodlands and fields across the country, whether it’s the snowy effect of thousands of snowdrops growing en masse, the shimmering sight and heady scent of swathes of bluebells or the exquisitely pretty display of native daffodils as far as the eye can see.
It’s a scene that can be emulated, albeit on a smaller scale, in a garden, and it can be a great way to add spring colour to otherwise tricky spots such as grass verges and banks, and the dry shade beneath deciduous trees, where the grass is short and there’s plenty of light in spring before the canopy unfurls.
How to do it
Plant spring-flowering bulbs in autumn. Most need to be planted in September or October to give them time to develop healthy roots before winter, whereas tulips are best planted in November or December as the colder soil helps to stop soil-borne fungal diseases from infecting the bulbs.
Take a handful of bulbs and scatter them over the area you’d like to cover. The aim is to create something that looks natural – ideally you’re looking for a mix of clusters of bulbs along with individual bulbs – outliers – in between. Any bulbs that land too close together can be moved a bit further apart to give the bulbs room to spread.
For large bulbs, such as tulips and daffodils, use a spade or bulb planter, making a hole at least three times the depth of the bulb. Drop in the bulb, backfill with the soil and replace the turf, pressing it down so it’s flush with the surrounding lawn.
It would take too long to use this technique for smaller bulbs like crocuses, so instead grab a spade and lift a section of turf, peeling it back. Fork over the soil a little, then plant a handful of bulbs in a random pattern. Replace the turf and firm it down.
If you’re planting underneath a tree choose small bulbs, such as crocus, cyclamen and scilla, as these will be easier to plant in the thin grass among the tree roots.
It’s important to allow any bulb foliage to wither and die back as the energy and nutrients stored in the leaves will go back into the bulbs, meaning they will produce better flowers next spring. It can take six weeks for the leaves to fade, so this does mean you’ll need to wait before you can mow. For this reason early-flowering bulbs work well because they flower and set seed before the grass starts to grow. However, it’s also possible to naturalise bulbs that flower later if you plant these in areas where you’re happy for the grass to be left to grow long.
So here are my tips for the best bulbs to naturalise underneath deciduous trees:
- Cyclamen coum and the autumn-flowering Cyclamen hederifolium
- Our native daffodil (Narcissus pseudonarcissus)
- Our native bluebell (Hyacinthoides non-scripta) – it can become invasive, so it’s best suited to large areas
- Tulipa sylvestris
- Winter aconites (Eranthis hyemalis)
- Wood anemone (Anemone nemorosa)
- Dog’s tooth violet (Erythronium)
And these will work well planted in grass:
- Snake’s head fritillary (prefers moist soil)
- Species daffodils – Narcissus obvallaris and poeticus
- Hybrid daffodils – ‘February Gold’, ‘Jack Snipe’, ‘Thalia’
- Species tulips – Tulipa clusiana and sprengeri