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Soil and Preparation: Gladioli are one of the easiest flowers to grow. They do well in a wide range of soil types – provided drainage is good, but they grow best in soil with a pH of 6.5 to 7. Most garden soil that will produce a good crop of vegetables or weeds will also grow good glads with little added fertilizer. Glads prefer full sunlight, but will do reasonably well with a little shade in early morning or late afternoon. Good circulation is desirable, so stay away from buildings or other obstructions, which might impede airflow. Plow, rototill, or spade your soil as you would for any other garden plants. It is best to move your glad plantings from one area to another each year to help prevent carryover of diseases in the soil. If soil tests or other reliable indicators point to a lack of nutrients, a balanced commercial fertilizer may be incorporated into the soil immediately prior to planting. Avoid over fertilizing. Composted animal manure or leaves should only be worked into the soil in the fall.

Planting: Your first planting should be when you would normally plant sweet corn. Corms (commonly called bulbs) planted in cold soils are apt to rot before they begin to grow. Subsequent plantings at two-week intervals will ensure bloom over a long period of time. We recommend planting corms three to five inches deep and from four to six inches apart, in rows spaced 12-36 inches apart. Insecticide spread in the trench before covering will discourage underground insects. Before glads bloom, hilling soil six inches up around the stalk helps prevent the glads from tipping over during storms. If drainage is a problem in your soil, rows should be raised to facilitate the process. Soggy, compacted soil will hamper root growth and contribute to root rot.

Watering: Remember that glads need plenty of water, but will not tolerate wet feet. Lack of water inhibits spike growth, flower development and bulb growth. At least an inch of water per week is a good guideline.

Fertilization During Growing: We recommend fertilization when the third or fourth leaf is visible, applied as a side dressing. Espoma Plant Tone or Espoma Bulb Tone are ideal choices.

Weed and Insect Control: Weed by shallow cultivation and hand weeding. If available, a light mulch of straw, grass clippings, etc. between rows will discourage weeds and help conserve moisture. Insect control is important in growing glads. Pests include thrip, which is by far the most damaging. Thrip are tiny insects, tan to black in color and less than 1/8” in length. Fertilome Organic Triple Action works best for thrip control.

Digging Corms (Bulbs): You will need to dig your corms each year, or if you choose not to dig, purchase new corms in the spring. Corms should be lifted in the fall before the onset of freezing weather. About 6-8 weeks after blooming, the corms may be harvested by loosening the soil with a spade or digging fork so that the plants can be pulled up by hand. The plant should be separated from the corm as close to the corm as possible, either by hand breaking or by cutting with pruning shears. The corms should be cleaned or rinsed off with running water, and then spread out to dry in shallow layers in trays or porous bags in an airy location that will not freeze for a period of 2 to 3 weeks. During this time a cork layer forms between the new corm and the old mother corm and roots. Break off and discard this old corm as soon as possible. Undue delay in cleaning results in greater difficulty in removal of the old corm.

Corm Storage: After cleaning, corms should be lightly dusted with a combination fungicide/insecticide dust, placed in shallow trays, mesh bags or open paper bags to be stored for the winter. Do not use any covering material. A well-ventilated root cellar is ideal, but any room with good air circulation in the average home basement will suffice. The lower temperature is best, as long as they do not freeze.