Plant Pathology Infobytes

October 3, 1999
Plan Ahead for a Beautiful Spring 2000 Flowering Bulb Crop

Tulips, daffodils, and many other types of spring flowering bulbs are in bountiful supply at nursery and garden stores, and it's close to time for making your selections and getting the bulbs into landscape beds. There's nothing like a beautiful planting of daffodils or tulips to signal the arrival of spring, and if you plan ahead your landscape can be the envy of the neighborhood.

Bulbs are among the easiest plants to grow and maintain. However, like most other plants, they can be attacked by fungi, nematodes, and bacteria. Bulb rot is the most serious disease which affects flowering bulbs in the South, but, as a general rule, this problem can be avoided if careful attention is paid to soil preparation and bulb selection.

The following are suggestions for bulb rot control.

  • Buy bulbs from a reliable source and examine them closely before purchasing. Look for large unblemished, top-quality, well-cured bulbs. Try to find those that are certified as virus-free.
  • Practice rotation in flower beds. This means don't plant the same kind of bulb in the same site every year. If practical, rotate with non-bulbous plants.
  • Plant at the recommended time, depth, and spacing, in a well-drained and aerated soil.
  • Avoid planting in low, poorly-drained soils which are favorable for development of bulb rot.
  • Do not use excessive amounts of nitrogen, phosphorous, or organic matter. Follow recommended fertilization guidelines.
  • Bulbs should be handled carefully before and during planting; avoid bruising.
  • Not all bulbs are going to be in perfect condition, so sort through them and discard those that are spotted, partially rotted, or moldy. Also, look for bulbs with cuts, bruises, sun scald, or other injuries.
  • Other symptoms of poor-quality bulbs may not be readily detectable. Look especially at the neck and basal areas of bulbs for signs of rot. If there is any doubt, try the water immersion trick. Healthy tulip bulbs immersed in water will sink, decayed bulbs will float.
  • As an additional precaution, protect healthy bulbs from rot which could occur after planting by soaking them 15 to 30 minutes in a warm suspension of a fungicide such as Rico's Best Rose and Ornamental Fungicide, or any fungicide which contains thiophanate methyl (ask your garden supply or nursery dealer about other brands of fungicide which contain this fungicide as the active ingredient). After soaking, allow bulbs to dry before planting.
  • Most bulb containers have guidelines for the recommended planting depth; follow these as an additional precaution against bulb rot and "spotty" emergence of the planting.

Your home landscape can come alive next spring with beautiful displays of tulips and daffodils if you take the time to start the bulb planting season with high quality disease-free bulbs and plant them correctly. If you have questions or need additional information on recommendations for use of bulbs in the home landscape, check with us at the County Extension Office.


Written by the late Dr. Frank Killebrew

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