Planting bulbs, corms and tubers is an easy way to ensure colourful displays in your garden, particularly in spring before the rest of the garden has woken from its winter dormancy. Bulbs can be planted in containers or borders, and look particularly effective when naturalised in grass. There are bulbs, corms and tubers to suit all sites and soils. So if you are wondering how deep to plant daffodil bulbs, how to plant up begonia tubers or when to plant tulips, take a look at our planting depth charts below and discover how easy growing bulbs can be!
Different species will require different growing conditions and you can check their preferred position in our bulb planting depth chart below. As a rule, most will need a well drained soil that won’t sit waterlogged in winter which may cause them to rot.
Always plant bulbs with the pointed growing tip facing upwards. If it isn’t clear which is the top then try planting bulbs on their side. Some tuberous plants such as Begonias will be flatter than bulbs and don’t have an obvious growing point. Position them just below the compost surface with the indented side facing upwards.
Planting bulbs in containers allows you to move your display into prime position while they are in full bloom. After flowering the containers can be moved out of view while the bulbs die back and become dormant. Use a good quality general purpose compost and mix in a handful of fine grit to improve drainage. Alternatively you can choose specially prepared bulb compost.
Water bulbs in containers regularly as they begin to grow, and continue throughout their flowering period. Once the foliage begins to die back you can gradually reduce watering as they enter their dormant period.
If squirrels and mice become a problem then protect your containers of bulbs by covering the top of the pot with a piece of chicken wire. Once the shoots appear you can remove it to allow the foliage and flowers space to grow.
Naturalising bulbs in grass can make an impressive display. They are best grown in informal areas of grass that can be left unmown while the bulb foliage dies back.
For a really natural look, gently scatter them across the planting area and plant each one where it lands. Use a sturdy trowel or bulb planter to dig a hole to the recommended bulb planting depth and drop the bulb into the hole, making sure that it is facing the right way up. Cover the bulb with soil and gently firm the earth around the bulbs to fill any pockets of air. Avoid treading the ground afterwards as this may damage the bulb growing tips as the soil settles.
If you are planting large numbers of bulbs then it may be simpler to lift an entire piece of turf with a spade and arranging the bulbs beneath it before relaying the turf.
Bulb planting depths vary depending on their size and species; but as a rule of thumb, most bulbs can be planted at a depth of approximately 3 times their own height. Some tubers, such as Begonias, are best started off indoors or in a frost free greenhouse before transplanting outdoors. Full growing instructions can be found on individual product pages.
| Bulb/Tuber | When to plant bulbs | Bulb Planting depths | Planting distance between bulbs | Position |
|---|---|---|---|---|
| Allium bulbs |
|
10cm (4") | 10cm (4") | Full sun |
| Begonia tubers |
|
1cm (1/2 “) | 30cm (12”) | Full sun, semi shade, dappled shade |
| Crocus bulbs |
|
10cm (4") | 7cm (3") | Full sun, semi shade |
| Daffodil bulbs |
|
10cm (4”) | 10cm (4”) | Full sun, semi shade |
| Dahlia tubers |
|
15cm (6”) | 45cm (18”) | Full sun |
| Bluebell bulbs |
|
10cm (4”) | 10cm (4”) | Dappled shade |
| Gladiolus corms |
|
10cm (4”) | 15cm (6") | Full sun |
| Hyacinth bulbs |
|
10cm (4”) | 8cm (3”) | Full sun, semi shade |
| Iris reticulata bulbs | |
10cm (4”) | 8cm (3”) | Full sun |
| Lily bulbs | |
20cm (8”) | 15cm (6”) | Full sun, semi shade |
| Narcissus bulbs | |
10cm (4”) | 10cm (4”) | Full sun, semi shade |
| Ponerorchis tubers | |
2.5cm (1”) | 7cm (3”) | Dappled shade |
| Ranunculus corms |
|
8cm (3”) | 25cm (10”) | Full sun |
| Snowdrop bulbs |
|
10cm (4”) | 10cm (4”) | Dappled shade |
| Tree lily bulbs | |
20cm (8”) | 15cm (6”) | Full sun, semi shade |
| Tulip bulbs | |
15cm (6”) | 13cm (5”) | Full sun |
| White Egret Orchid tubers | |
2.5cm (1”) | 7cm (3”) | Dappled shade |
| Winter Aconite bulbs | |
5cm (2") | 5cm (2") | Full sun, semi shade, dappled shade |
Plants and gardens have always been a big part of my life. I can remember helping my Dad to prick out seedlings, even before I could see over the top of the potting bench. As an adult, I trained at Writtle College where I received my degree, BSc. (Hons) Horticulture. After working in a specialist plantsman's nursery, and later, as a consulting arboriculturalist, I joined Thompson & Morgan in 2008. Initially looking after the grounds and coordinating the plant trials, I now support the web team offering horticultural advice online.
