From the " Dutch" Garden

When most gardeners think of "Dutch" bulbs their minds turn to windmills and acres upon acres of tulips, daffodils and hyacinths. While "spring flowering" bulbs are indeed a mainstay of most American gardens, an entire range of flowering possibilities is not given the attention it deserves. We are talking about the "other" Dutch bulbs-summer flowering "bulbs" such as dahlias, gladiolous and liliums.

In fact they are not really "bulbs" at all, but rather a range of bulbous plants that include corms (gladiolous), tubers (dahlias) or rhizomes (iris). What they do have in common with tulips, daffodils, and even the minor bulbs such as crocus is that a portion of the plant is swollen into a food storage organ that allows it to winter over, or survive while dormant. Understanding that the food or nutrition is stored in the base of the plants is an important point. This is why we recommend that most spring flowering bulbs are not cut back until their foliage turns brown. Although you may take the stem with flower for cutting, try to leave as much foliage exposed to absorb nutrients from the soil, water and sunlight. Tying back spent foliage on daffodils might tidy up your garden, but it can impact flowering in following seasons.

Spring flowering bulbs, for the most part, can make it through our winters without any additional maintenance. However, most summer flowering plants do need to be lifted in the fall and stored properly. There is no need for confusion when it comes to which bulbs can be over-wintered and which bulbs, tubers and corms should be lifted and stored. However, many gardeners have still yet to discover the incredible range of color, shape and variation of blooms that await them in these beautiful flowering plants. The added bonus is that dahlias, gladiolous and even begonias grow larger with each season and can be multiplied with simple propagating techniques.

Defining your terms-While you certainly do not need a degree in botany to enjoy your garden, some simple definitions might be helpful in understanding the types and variations of the options available to you.

Bulbs-True bulbs, usually recognized by fleshy leaves, are generally sold in garden centers in the fall and include tulips, daffodils, hyacinths, some lilies (Lilium) and fritillaria species. This category would include many minor bulbs such as muscari, reticulata iris, and snowdrops. With some exceptions these bulbs are planted in the fall and do not require lifting the following season.

Corms-If you were to lift a gladiolous stem in full bloom, you would gain an immediate understanding of how this gorgeous plant grows. Compared to a geranium or other typical bedding plant, it does not possess an intricate root system, but rather a swollen, bulbous stem. In fact the roots, as we know them, seem spindly. Corms are common in the family Iridaceae, which also includes crocus (both spring and fall flowering).

Tubers-When you think of tubers, you probably think of potatoes! And you are correct. Tuberous plants, such as dahlias, have swollen, often irregularly shaped stems or roots that are used for food storage. Divisions of dahlias are often sold in the spring and can be planted out about three weeks before the last frost which will generally occur around the middle of May. Their tubers are generally connected to an identifiable stem. When buying dahlias, the larger the tuber (depending on varieties, miniatures will of course be smaller) the better.

Rhizomes-Most recognizable are the bearded iris. They are planted horizontally...shallow, and will benefit from division every three to four years. They are clump forming, hardy and easy to care for.