UNITED STATES—Spring bulbs begin to go into the garden during autumn to benefit from the chill of winter. Summer bulbs begin to go into the garden during late winter to avoid the chill of winter. Spring bulbs know to remain dormant through winter. Some summer bulbs do not. If they grow prematurely, they can be vulnerable to cool wintry weather. Late is better than early.
Frost is still possible within some climates. However, summer bulbs are now in season. That is because, like spring bulbs, they disperse roots prior to developing foliage. By the time they extend foliage in a month or so, the weather will not be so cool. Later phases of a few sorts bloom later to prolong bloom for the first season. They synchronize afterward.
That is because they establish themselves within the garden. Once they do, some types of summer bulbs become hardy perennials. Some might try to grow prematurely during subsequent winters. If they incur frost damage as established perennials, they can easily replace the damage. Ornamental gingers and cannas do so regularly in inland climates.
Some summer bulbs are more sustainable than spring bulbs.
Ornamental gingers and cannas may eventually benefit from division. Even if they do not become too crowded, they can migrate where they are not wanted. Their surplus is easy to relocate or share while dormant for winter. Their foliage becomes shabby or dies back during dormancy anyway. Even if mostly green, its removal stimulates healthy refoliation.
Ornamental gingers and cannas also are oblivious to phasing. Gingers bloom only once for late summer or autumn. Cannas bloom randomly from spring until autumn. Gladiolus bloom only once like gingers, but are more conducive to phasing. Early planting allows early bloom. Late planting delays bloom. Unfortunately, they are much less sustainable.
If summer bulbs do not look like bulbs, it is because few actually are. Most are rhizomes. Dahlias, which, like cannas, bloom from spring until autumn, grow from tuberous roots. As the name implies, tuberous begonias grow from tubers. Crocosmias grow from corms. So do taros, which are large foliar perennials. Gingers and cannas are familiar rhizomes. Although alliums bloom as summer bulbs, they go into the garden along with earlier spring bulbs.
Highlight: Asian Taro
Both alocasias and colocasias are striking foliar plants. Alocasias generally develop big leaves that point upward. Colocasias generally develop even bigger leaves that hang downward. Alocasias are generally more colorful, perhaps with striking foliar patterns. Also, most tolerate more shade than colocasias. Of course, these are generalizations.
Asian taro, Alocasia odora, resembles colocasias as much as alocasias. Its big cordate leaves may point only slightly upward, and might sag downward. They can grow two feet long and a foot wide, on petioles as long as three feet. Collectively, foliage can get more than five feet tall. It is bright but monochromatic green, similar to that of Kermit the Frog.
Asian taro is only occasionally available from nurseries. Small plants are too delicate for nurseries to market too many of them for too long. Their dormant bulbs are more likely to become available with summer bulbs. They can be wider than three inches! They grow slowly though, especially while weather is cool. Foliage may not appear for two months.
Tony Tomeo can be contacted at tonytomeo.com.
