Perennial Plant of the year 1999
L.O. Excellence Awards 
The Pennsylvania Horticultural Society’s Gold Medal Plant Award 
A Summer Bulb Primer 
100 Best Plants
for the Ontario



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A Summer Bulb Primer

Summer-flowering bulbs, corms and tubers are becoming an increasing popular staple of the summer garden. More and more gardeners are discovering that the flowering periods of some of these plants, such as dahlias and tuberous begonias (early summer to first frost), far surpass those of almost any other garden plant.

As well, summer bulbs are being recognized as being able to fulfill Canadian gardeners’ continuing quest to have something ‘new’ and ‘different’ in their gardens. Most recognized in the summer bulb/corm/tuber family are the ‘big three’ - dahlias, begonias and gladioli. But there are so many more, for example:

  •  Acidanthera, the Abssyinian gladioli with its fragrant, 10 cm white flowers with reddish purple centres.

  •  Agapanthus, with its tall, imposing stem topped with masses of blue-purple flowers making up each blossom and its glossy, strap like, evergreen leaves which are decorative even when the plant is not in flower.

  •  Canna, with its enormous Canna Bengal Tiger And Tropical Canna white, scarlet, apricot, coral, pink, or yellow blooms and lush, tropical foliage.

    The extremely popular Eucomis, better know as the pineapple lily with its tuft of small leaves crowning a dense spike of blooms.

  •  Galtonia which bears up to 30 white or green-tinged nodding flowers on each sturdy one meter spike rising above its strap like leaves.

  •  Gloriosa, or climbing lily with its dramatically shaped yellow and red flowers, glossy tendril-tipped leaves and vine-like habit.

You’ll notice, we have only arrived at ‘G’ in the alphabet. There are so very many more summer bulbs from which the savvy, adventuresome gardener can choose.

Where to plant

Summer bulbs are at home in almost every type of location. They are a wonderful addition to perennial borders as there are short, medium-height and tall varieties from which to choose, making those important splashes of colour possible everywhere.

Their wide assortment provides the ideal flowers for any style of garden, be it formal, cottage, minimalist, cutting, traditional or eclectic.

Pots and containers

One area in which summer bulbs and their corm, tuber and rhizome cousins are especially well suited, is in pots and containers. No longer is the condominium, apartment or patio owner limited to a few flats of impatiens and geraniums.

It’s all possible. Colourful pots of: elegant lilies; unique, fragrant Peruvian daffodils (Hymenocallis); tropical Cannas; pretty-in-pink Nerines; the clustered, white, star like blossoms of Ornithogalum; multicoloured Ranunculus or Persian buttercups; one of the showiest of bulbs Tigridia with its brilliantly coloured, uniquely marked flowers - and, once again, the list could go on, and on.

Summer bulbs grow and thrive in all sorts of pots and containers, with the one caveat, that they all have good drainage, as none of these plants like ‘wet toes’.

The garden owner could also do well to pot up some summer bulbs to use as movable splashes of colour in locations that are temporarily between blossoms.

When to plant

When to plant depends on the type of bulb. In many years, gladioli corms can be planted as soon as early May. Although not winter hardy, by the time the corms are 10 cm underground, the last ground frosts of spring will have little chance of harming them. On the other hand, since tuberous begonias are covered with only one cm of soil, they shouldn’t be planted until late May. The planting times for all other summer-flowering bulbs fall between these two extremes.

How to plant

Planting can be done in a variety of ways. If planting small quantities of each kind, the best method is to arrange the bulbs where you want them and then dig a hole for each one with a trowel. If planting large quantities, consider removing all the soil at that location down to the level where the bulbs will be planted.

Planting depths differ wildly. Some are planted two to three times as deep as they are high, others are covered with only a centimetre of soil. Packaged summer-bloomers will have planting instructions on the wrapping. If you are buying loose bulbs, double check planting instructions with garden centre staff.

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Copyright 2001