Fertilizer quantity for gladiolus

Question

How much fertilizer should I apply to Gladiolus to achieve 120cm sized stems with maximum number of plants producing it? Early bloom had 120cm but later bloom’s length of stem shortened. Also, 50% plants were green foliage & did not produce any stems.

My soil analysis report: Texture- Loam, pH- 8.2, P- 5.1mg/kg(poor), K- 107mg/kg(medium), OM- 0.48%(poor), Cu- 2.4ppm, Fe- 16.6ppm, Mn- 1.6ppm, Zn- 1.9ppm.

Appreciate your guidelines to adjust my fertilizer quantity. Thanks.

Answer 1

Fertilizer is a hot button among plant people; it probably stirs up more debate than any other single subject, and specialists develop many different mixtures for every imaginable situation and plant variety. So there’s no one “right” or “best” way. That being said, your soil analysis shows that you need to do something to lower pH – glads like a pH 6-6.5. This article will give you some ideas: https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/raise-acid-level-soil.htm Also, you’ll want to concentrate especially on raising P and increasing OM. My personal recommendation would be to work in as much organic matter as possible, especially a lot of peat and bone meal, then fertilize as recommended with a high-phosphorous (1-2-1 ratio) fertilizer. This article goes into more detail about fertilizing bulbs: https://www.gardeningknowhow.com/ornamental/bulbs/bgen/preparing-soil-for-bulbs-and-fertilizing-bulbs.htm
Remember that the size of your flower stems and flowers is going to depend a lot on the variety you’re using. This article goes into more detail, and recommends 2lbs of 5-10-5 per 100 sq.ft.: https://extension.missouri.edu/p/g6620