Perennial Tulips :

IT'S A COMMON FRUSTRATION:

You buy tulip bulbs, plant them in the fall and enjoy a great display in the spring. But the following spring, all you get is a smattering of flowers and maybe a bunch of leaves. "What happened?" you ask yourself. "Aren't tulips supposed to come back? My grandmother has tulips that have bloomed every spring for as long as she can remember. Did I do something wrong?"

PAMPERED BEGINNINGS

More than likely, you are not to blame. It's in the nature of tulips. Most are not strong perennializers in the land- scape. They don't flower well the second year after planting.

Why don't tulips come back? The tulip bulbs you buy and plant in the fall have been groomed to bloom. They were raised in sandy Dutch soil and fertilized in just the right measure. When they bloomed in the spring, the flowers were cut off soon after they opened to keep them from drawing too much energy from the bulbs. The leaves were allowed to continue to grow for another six weeks in the famously cool Dutch weather. After going dormant in early summer, the bulbs were dug and stored in a climate-controlled warehouse to mimic a long, hot, bone-dry summer in the mountains of Central Asia, which is where most tulips are native.

SPLITSVILLE USA

All of this TLC yields a high percent- age of flowering-size bulbs, including many topsize bulbs, which measure 12 centimeters in circumference or larger. A topsize bulb can't get bigger, but it will get smaller, typically by splitting into two or more smaller bulbs. Under less-than-perfect garden conditions, when the bulbs split into smaller bulbs, those smaller bulbs may take years to grow to flowering size. Some may also rot due to heavy soil or excess moisture. And so your breathtaking tulip display dwindles to little or nothing.

BUCKING THE ODDS

Despite the obstacles, there are some tulips that are willing (but not guaranteed) to bloom well for more than one year. The best known are the Darwin Hybrids, but other types, such as the Fosterianas, and many of the wild, or species, tulips also have perennial tendencies. They won't keep going indefinitely, but it's possible to get two or three reasonably good displays from them before you feel the need to replant.