The Passionate Gardener: April 2016

April 1, 2016

Summer – Flowering Bulbs

By: Ron Kushner

Keeping blooms in your garden all summer long.

Summer bulbs are now on sale again. It’s time to get reacquainted with Dahlias, Begonias, Lilies and gladiolus. Not all of the bulbs are cold hardy but those that are not can be saved indoors and replanted year after year.

As a general rule, plant bulbs at a depth of two times the largest diameter of the bulb. Place the bulb in the hole with the pointed end up. Which way is up is not always apparent, so when you purchase your bulbs, ask a professional in the store for advice. Mix some fertilizer with the soil (Espoma Bulb-Tone is recommended), cover the bulb with soil and water well. Space them far enough apart to allow for good air circulation once they are blooming. Bulbs can be used in any garden or patio setting, giving you flowers, fragrance and brilliant color with very little effort.

Lilies distinguish themselves by their dazzling colors and shapes. Important additions to any garden, these hardy, true bulbs prefer full sun to partial shade and well-drained soil. Lilies can reach heights of 2 to 5 feet and produce magnificent blooms in mid to late summer. Many Oriental varieties such as ‘Casa Blanca’, ‘Stargazer’ and ‘Mona Lisa’ are very fragrant. They also tend to be the latest to bloom. Lilies can be planted as early as possible in spring. Oriental lilies, Asiatic varieties, trumpet types and the common, tiger lilies are all popular and available.Give good winter mulch, especially during the first winter. Lilies never go completely dormant, so plant the fragile bulbs carefully soon after you buy them. Stake tall lilies and deadhead after blooming, after the tops die back, cut the stems to a few inches above the ground.

Superb at cut flowers and effective in the border, Gladioli offer a spectrum of colors varying from the familiar red, white and yellow to intermediate shades of multicolored varieties. Blooms start to open from the bottom of the spike upwards and a full two weeks of continuous color can be obtained from one plant alone. Plant “Glads” in sunny locations at two week intervals for season-long color. Most need to be staked individually as they tend to blow over or even fall under their own weight. Dig up corms in the fall and store for the winter (although I have had many come back in the spring when covered with heavy, winter mulch).

Begonias, in their many shapes and colors, are best known as plants for containers. However, there are many other ways to use begonias as well. Beautiful hanging begonias like ‘Champagne’ are an asset to any balcony. Single and double flowering varieties make an ideal ground cover and border design. These ‘non-stop’ begonias are well-named as they flower constantly through summer and well into fall. Start begonias indoors in a lightweight potting mix, and then move outdoors to a partial shade location after the last frost. Move plants back indoors before the first frost or store tubers over winter and replant year after year.

Since Dahlias continuously produce new flowers, you can enjoy their rich display of color right up to the first frost. They come in many different varieties and colors, ranging in height fro 2 to 4 feet with flowers as small as 1″ across to the large-blooming “dinnerplate” types with 12′ wide blooms. Two elegant variations are the quill-petalled “cactuses” and the elongated “spiders”.

Dahlias require rich soil with extra potassium and phosphorous and full sun to partial shade. Plant them after all danger of frost is past in deep, fertile, moist but well-drained soil. Enrich the soil with plenty of organic matter (compost is best). Set the roots horizontally 3″ to 6″ below the soil surface. Don’t cover unsprouted tuberous roots completely at planting time. Gradually fill in the holes as the plants grow and stake immediately after planting 6″ from the growing plant. Water often and fertilize liberally throughout the summer with fish emulsion, bonemeal or other fertilizers not excessively high in nitrogen.

Remember to move tuberous roots indoors for the winter after a killing frost and store in barely moist peat or vermiculite.

Other interesting summer-flowering bulbs
Keep on the lookout for hardy cyclamen, Calla lilies in a wide variety of colors, Cannas, Acidanthera, Elephant ears, Caladium, hardy Gloxinia, Agapanthus and anemone, also in a variety of colors.

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