Daffodils and other spring flowering bulbs always make for a nice surprise – you bury the bulb in autumn, it lies dormant all winter, then - boom - all of a sudden a bright flower appears to tell you spring is coming.
Bulbs are easy to grow and need very little attention. They can be grown throughout New Zealand and while they come in a wide range, traditional yellow daffodils are still the crowd favourite. There are bulb plants suited to all of the varying New Zealand climates, so remember to purchase bulbs based on suitability as well as the look of the flower.
Planning
Autumn is the best time for planting spring flowering bulbs, as the soil temperature has dropped and the bulbs will be dormant and ready to be planted (or divided and transplanted for existing crops). Daylight saving changeover is a good seasonal marker for this. The best selection of bulbs are usually available to buy from mid February through to the end of March/early April, these bulbs should be stored in a refrigerator until autumn planting. Popular spring flowering bulbs are: Anemones, Hyacinths, Tulips, Irises and Daffodils.
Summer flowering bulbs such as Nerines, Dahlias, Begonias and Lilies are planted in winter through to early spring. (See our guides on lilies for more information on these.)
When choosing the planting site, look for free draining soil and plenty of sun. If you are only able to use soggy or shaded soil, choose varieties that are more suited to your garden, or consider container planting. Some spring flowering bulbs such as Lily of the Valley, Snowflakes and Bluebells flower happily in shade, and there are also a few (such as the Japanese Iris and Arum Lily) that will tolerate damp soils.
Prepare the bulbs
Choose firm, large bulbs – generally the larger they are the better the flowers they will produce.
Dust the bulbs lightly before planting with a mite and mildew powder as this will help prevent powdery mildew and red spider mite, and will add protection from frost as well as helping overall plant growth.
Planting
Plant your bulbs in moist, well-drained soil. If your soil is heavy or dry and sandy, mix through some compost or well-rotted organic material. Adding blood and bone or bulb food can also be beneficial if your soil is lacking nutrients.
In heavy clay soils where drainage is poor, or where roots from surrounding trees and shrubs are a problem, plant bulbs in raised beds. Adding sand to the planting hole will improve its drainage.
Dig in a handful per square metre of bulb specific fertiliser (mix in thoroughly or it will burn the bulbs).
As a rule of thumb, plant bulbs twice as deep as their width. For example, if a bulb is 4cm wide, plant it to a depth of 8cm (to the top of the bulb). If they are too shallow, it won’t flower. Separate the bulbs by approximately 10cm. Always check packaging though for specific instructions,
Mulch the area and water well.
Maintenance
Maintenance
When the buds and leaves appear, feed them occasionally with soluble bulb food fertiliser or blood and bone, and then again straight after flowering.
If you mix your bulb varieties, you can extend the flowering period of your bulb patch into summer.
Watering
Spring flowering bulbs rarely need watering thanks to winter rain. Summer and autumn flowering bulbs may need additional water during their growing season depending on the weather.
Pests and diseases
Bulbs are relatively pest and disease free. Protect the new shoots from slugs and snails with an appropriate insecticide.
Planting bulbs in pots
Bulb also grow well in pots. The shorter growing, and miniature flowered varieties are ideal for containers. The best spring flowering bulbs for pots are Daffodils, Tulips, Freesias, Hyacinths, Bluebells and Crocus. Summer flowering bulbs that are suitable for containers are Begonias, Calla Lilies, Dahlias, and Lilies.
Choose a container that has good drainage.
Fill your container with a bulb specific potting mixture that contains a slow release fertiliser and place bulbs evenly throughout the container, try not to let the bulbs touch each other, or the walls of the container.
Place the pot in a shady place and water it regularly until shoots appear, then move the pot into full sun.
To make the pot more attractive and suppress weeds while you are waiting, plant winter flowering perennials on top of the bulbs.
Give the plant some liquid fertiliser when the foliage appears, and then again several times throughout the season (this will benefit flowering).
If you want to reuse the pot and bulbs again the following year, after flowering when the leaves begin to yellow, dry the pot soil out completely. Move the pot with the bulbs undisturbed to a dry place for summer. In the following autumn, knock off the old potting mix and replant the bulbs into fresh mix or plant them in the garden.
Reuse and recycle bulbs
Bulbs can be left undisturbed for several years and only need lifting and dividing when they become overcrowded, or if the soil is wet enough to rot the bulbs over summer.
As the bulbs finish flowering, fertilise them with bulb food. The bulb will use this food to feed the bulb for next season's growth.
The leaves hold the bulbs food supply for the following year, so need to be kept intact. Tie the foliage in a knot or fold the foliage over and secure with a rubber band to tidy them up once they start to look messy. One way to camouflage this messy stage is to plant annuals and perennials around your bulbs.
Bulbs can be lifted out of the soil when the foliage starts to die down.
Leave the foliage attached until it dries off naturally and then remove it. Store your bulbs in a net bag or seed tray in a cool, dry, airy place.
Separating
To separate crowded bulbs, ease a fork under the group, wriggle the bulbs out of the soil and separate the clumps apart like you would a clove of garlic. Now you can re-pot them in the appropriate potting mix.
Naturalising
Daffodils are the easiest bulbs to `naturalise`. Naturalising is where bulbs are left in the soil for several years (or indefinitely), to multiply and flower year after year until they become overcrowded. At this stage you can dig the bulbs up, separate the bulbs, and replant again. This is a good option for parts of the garden that don’t get disturbed (under deciduous trees or grassy areas).
Varieties for naturalising
Active and robust varieties of flowering bulb are the best for naturalising. They will need to survive potential frosts, the possibility of soggy soil and be able to produce strong enough shoots to push through undisturbed soil. Check the packaging to see if the variety you have chosen will survive being naturalised (and whether they are frost hardy if you are in a frost prone area). The most economic bulbs for naturalising are the mixed packs of bulbs.
If you are naturalising bulbs in an area that you mow, allow at least six weeks after flowering before mowing the area. This means the bulb has been able to store its food for next year.
