The Summer Bulb Growing Guide

Summer bulbs can offer some of the most stunning flowers. Plant them in late Winter or early Spring and you’ll have a gorgeous display come Summer. Below are some of our favourites and the top tips to get the most out of your flowers.



Adored the world over, Dahlias are certainly a show stopper! Available in a rainbow of colours, Dahlia will reward you with endless stems of flowers which are perfect for picking. If your garden could use a little magic, add a few dahlias.

Outdoor Beds

If you’re planting your Dahlias in outdoor beds, find a sunny spot with well-drained soil. If you still have water puddles 5-6 hours after hard rain, scout another location. Soil can be amended with organic material to raise the garden bed 10cm to help improve drainage. Manure, compost or bark all work well. Dahlias need to receive full sun for you to fully enjoy their flowery goodness. Wait until the threat of frost has passed before you plant. Don’t be tempted to get them in the ground too early, their delicate growth can’t cope. Make sure that the soil is warm before you decide to plant.

Pots or Containers

Select a pot or container that has drainage holes and fill with a good quality potting mix. Make sure that you don’t overcrowd your container with tubers, some varieties of dahlia like lots of space! Pop your planter in a nice sunny spot and wait in anticipation.


Dig holes and plant your dahlias with around 10cm of soil above them, spacing 30 – 60cm apart. Some can be obscure in shape, so look for the tuber that appears to have the most ‘eyes’ or growing points. Plant with the eyes facing upward. After planting, water lightly. Roots and sprouts will begin to form quickly.


Dahlias will develop buds in early Summer and will bloom through the Autumn until the weather cools, or if frosts begin in cooler regions. When in bloom, feel free to cut dahlias for indoor displays, or simply leave them be to colour your garden.

When blooming finishes for the season, don’t feel the need to chop away the foliage, leave it in place. The leaves will gather sunlight which provides nourishment for next year’s display. Make sure you water as needed. In very cold climates, if you’re planning on saving your tubers for the next year, dig them out a week after the first frost and let the tubers air dry for several days and store in a cool location in paper bags or peat moss filled boxes.



A darling of the plant world. Lilies resonate with Kiwis as a go to cut flower.


Plant your bulbs immediately, don’t allow the bulbs to dry out. Plant from August to October in a sunny spot that will get at least half a day’s sun with well-drained, slightly acidic soil. Work bulb food in to the planting area and cover bulbs with 10cm of soil, making sure that all growth points are well buried. They’re happy to grow in containers too, so even if you’re short on space, you can still enjoy the lovely lily. Avoid using animal manure.

Keep well-watered once the soil warms and new growth appears.


When cutting flowers to take indoors, leave one third of the plant when removing the flowers as the bulb stores nutrients for the next year. Pick flowers as the buds are just beginning to open.

After flowering has finished, leave the flower on the stem until it turns brown, then cut it off at ground level. Leaving the flower to wither on the plant allows the energy to be drawn back in to the bulb which prepares it for next year’s growth and flowering.

Good drainage is vital as the plant will die down and hunker down under the soil for the winter months after flowering. If the soil is too wet, the bulbs will rot and die. Bulbs can be lifted each Autumn and replanted in Spring.

Pot grown lilies should be repotted every two years or so. Liliums grown in the ground are best left for 4-5 years, this allows the bulb to grow large which in turn produces more flowers. Always replant immediately, don’t store or allow the bulb to dry out.



Towers of dramatic colour that are sought after for their stems of attractive flowers. These regal flowering swords have been a cut-flower market staple for many years. Planting at fortnightly intervals will give you long-lasting colour and prolonged flowering.


Gladioli can be planted from August to December. Plant the corms 10cm deep and allow 15cm between each. Find a sunny but sheltered position with good drainage for your gladys. They have a shallow root system so can be easily knocked over in strong winds.


Gladioli will flower for approximately 100 days after planting, so stagger plant in groups for a continuous display. Water often and avoid using animal manure. Some of the taller varieties may require staking.

Lift corms in Autumn to avoid rot, do not wait for the leaves to die back. Dry corms in a hot water cupboard or other such place and then store in a cool dry place to await the new season’s planting.



It is remarkable that such an unassuming brown tuber can produce a magnificent display of colour within a few weeks.


Begonias are great for pots on shady patios, preferring light shade to full sun. Wait until the threat of frost has passed before you plant. Choose well-draining soil to plant the tubers in, plant 3cm deep and 15 – 20cm apart with the indented side facing up. This is the side on which leaf sprouts will form. Ensure that they have adequate moisture, but do not over-water.

They can be grown in pots, hanging baskets and in the garden.


Begonias flower very quickly, providing a dazzling display.

Tubers can be lifted when the plants start to die down. Begonias do not multiply, but do get bigger every year.

Top tip!

Pinch off the smaller side buds to encourage larger flowers.