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Care, forcing, etc.

• Forcing bulbs

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Glads/Sword Lily (Gladiolus)

Improved types of glads were first developed from crosses of several species native to the Mediterranean area of Europe. Later discovery of African species led to crosses, which produced the forerunners of the attractive large-flowered types we know today. Although glads are used to a limited extent for landscape effect, their chief value is for cut flowers. Their wide range of colors, sizes and flower types makes them particularly useful for flower arrangements.

 

Planting

CStart planting in mid-May, then again every two weeks through mid-June. This schedule will keep the flowers coming form July through August. You could also choose early, mid-season, and late cultivars, plant them all in May, and still enjoy continuous bloom for much of the summer.

Gladioli can be grown well in many different soil types. If there is any possibility of selecting soils, a loam or sandy loam should be preferred. Soils with a pH between 6.0 and 6.5 and with medium fertility will give the best growth. If the fertility condition of soil is unknown, a soil test will help determine levels and indicate any need for improvement. Heavy soils with poor internal drainage can be lightened by adding organic materials such as compost. Also consider building of raised beds to improve the drainage.

Plant large bulbs 4 to 6 inches deep, medium-sized bulbs 3-4" (7.5-10 cm) deep and small bulbs 2-3" (5-7.5 cm) deep.

 

Summer care

To ensure tall, straight flower spikes, staking is necessary. Apply a layer of mulch such as straw, grass clippings, or pine needles to help keep weeds down. Pull or hoe any weeds that come up. Mulch will also help conserve moisture in the soil, cutting down on surface evaporation. Adequate rainfall or watering is still needed for best quality blooms, so be sure your glads receive an inch or water each week, if possible.

 

Cutting flowers

Bring a sharp knife or florist's shears and a tall bucket of lukewarm water to the garden with you. Cut the flower spikes first thing in the morning or at night, not during the heat of day. Cut spikes with only one, two, or possibly three flowers open; the rest will open in order, up the spike. Allow at least four leaves to remain on the plant if you wish to re-use the corms.

Cut diagonally through the stalk and place it in the lukewarm water immediately. Once you've collected all the glads you want cut, put the bucket in a cool, dark place for a few hours so the blooms "harden off". Use floral preservative in the vase water before arranging the glads. As lower flowers fade, nip them off. Cut about an inch of stem off the bottom of each spike every few days.

 

Overwintering

Corms are ready to dig in four to six weeks after blooms are finished or when the tops die off. They can be dug anytime before a hard freeze. After digging, wash off soil that adheres to the corm and roots. Remove the shoot and leave the corms in a light, airy place to cure. They are cured to get the surplus moisture out of the husks and corms as quickly as possible to prevent storage rots. After two to three weeks of drying, remove the old corm from the base. Sort the corms and cormels according to size. The small cormels can be saved and planted the following year, although they will take two to three years to produce the flowers.

Corms should be stored at a temperature of 35 to 45 F (2-8°C) in a well-ventilated area. Airy containers such as loose-weave baskets, mesh bags or old nylon stockings make good containers that may be hung out of the way.

 

Pests and diseases

Gladioli are relatively free of insect pests. The most troublesome pest is the gladiolus thrips. This insect is very small and seldom seen as it feeds in hidden places. It does considerable damage, especially to the flowers. It works on the buds before they emerge from the sheaths and causes malformed and spotted flowers. Thrips may overwinter on the corms. Aphids, grasshoppers and cucumber beetles are other insect pests that may cause damage to flowers or foliage.

There are many different disease organisms that attack the corms and stems of the gladiolus. Most are active during storage and develop with improper curing and storage. Before corms are planted in the spring, they should be carefully inspected. Pull back some of the husk to examine the inner surface and eliminate all corms that are infected. Although infected bulbs may grow if planted, growth is generally weak and stem rots often develop later to cause death. One of the best control measures against these rots is immediate removal and destruction of bulbs or plants that show disease.