In the northeast, the traditional time to plant many of our tender summer-flowering bulbs is “when the maples come into leaf.” That simply means that the ground is now warm enough to permit good root growth from the bulb, tuber or corm, while the air at the surface of the soil should be warm enough a few weeks from now for the top growth as it pokes through.

Warm temperatures, especially at night, are vital for these plants, which hail from hot spots like Africa (agapanthus, calla lily, galtonia, gladiolus, acidanthera and gloriosa lily); South America (tigridia, spider-lily and zephyrantes) and Mexico (dahlia and sprekelia). Plant them out too early and cold can stunt their growth.

Over the years, I’ve tried several of the less common summer bulbs with varying results. For example, when planted in containers, agapanthus needs to be potbound and often refuses to send up its tall stems with the starry blue flowers unless it is. If they don’t bloom the first year, bring them indoors to grow on and they should flower the second summer. In areas where agapanthus can grow outdoors year-round (Vancouver and San Francisco), they flower best in crowded clumps.

Tigridias, though unusual looking with their mostly yellow-and-red flowers (rather like open freesias), are rather hard to place in the garden, being quite short. They look best popping up near hot-colored summer flowers like yellow Coreopsis verticillata ‘Zagreb’ or annual orange Cosmos sulphurous. They’re interesting pot subjects too.

Spider lily (Hymenocallis festalis) has spidery, green-throated, white flowers on 2-foot (60 cm) stems. It loves rich, moist, organic soil and is spectacular as a pot subject, especially if its rather short bloom period coincides with a summer party, when its lemon scent permeates the night garden.

More satisfying for general garden fare are crocosmias (montbretias), with iris-like leaves and wiry, 3-4 foot (90-120 cm) arching flower stems in late summer. Flower colors range from orange (‘Emily McKenzie’) to brilliant red (‘Lucifer), making them perfect to liven up a stand of ornamental grass like Miscanthus sinensis ‘Gracilllimus’. With a thick protective mulch, corms sometimes winter over but it’s safer to dig them up in autumn and store them indoors.

In the “cheap-and-cheerful” category are acidantheras (Gladiolus callianthus, formerly Acidanthera bicolor). I like to plant these little bulbs in groups beside the patio. Then, when the elegant, wine-throated, white flowers open on 3-foot stems in late summer, their sweet perfume can be sniffed up close.

One intriguing bulb I’m seeing in lots of gardens and containers lately is pineapple lily (Eucomis bicolor). Exotic-looking with a pineapple-like rosette of leaves atop a plump flower spike covered with, purplish-green flowers, it makes a real conversation piece. Plant three to five in a large pot, perhaps surrounded by chartreuse ‘Margarita’ sweet-potato vine. In winter, store it in its pot in a cold room.

A bulb that will produce “wows” when you show if off to visitors is Aztec lily or Jacobean lily (Sprekelia formosissima). Native to Guatemala and Mexico, it has strap-like leaves and a spectacular, crimson-red flower that looks like an orchid. At about 12-14 inches (30-35 cm) tall, it makes a dramatic pot plant.

Lift all your tender bulbs before frost and follow the instructions on the packaging as to winter storage. This article will also help with some of the more common summer bulbs.

Adapted from a column that appeared originally in the Toronto Sun

Adapted from a column that appeared originally in the Toronto Sun

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