1. Home
  2. Expertise
  3. Diseases & Pests Advice
  4. Cyclamen


Mini Series: Libretto™, Midori™, Miracle™, Silverado™,SilverHeart™

Intermediate Series: Canto™, Laser™, Laser Synchro™, Sterling™

Standard Series: Concerto™, Delma™, Rainier™, Sierra™, Sierra Synchro™, Winter Ice™ 


1. Soil and pH Needs

In the landscape, cyclamen grow best in well-drained soils that are moist, but not wet. Soil that is too wet will rot the tuber, while the leaves will wilt and drop and the flower buds will fall off quickly if the soil is too dry. Heavy clay soils will retard root growth and starve the plant of oxygen, which can lead to root diseases. Soil should be amended with fully composted organic matter prior to planting and in the case of clay soils the addition of Canadian sphagnum peat moss and well-rotted compost are good sources of organic matter that will aid in aeration. If possible, incorporate two to three inches of organic matter into the top six inches of soil. If adding organic matter, be aware that organic matter that has not been fully composted will tie up nitrogen and sulfur leading to nutrient deficiencies and poor growth.  Soil pH should be 5.8 - 6.2 for optimum growth; and should be tested prior to planting but after adding any amendments. This can be done quite easily with a portable pH tester available for about $100. Mix one part soil with two parts distilled water, stir well and wait thirty minutes, then follow the instructions for using the pH meter. If pH is too low, the addition of lime is warranted. However, the rate will vary depending on how much you need to raise the pH and the type of soil you are dealing with. Clay soils or those with a lot of organic material have a high buffer capacity and require more lime than sandy soils, which have a low buffering capacity. A good soil testing lab can determine the lime requirement index (LRI) of your particular soil and can recommend types and rates of lime to use. Cyclamen should not be watered overhead if at all possible, drip irrigation is ideal for a successful cyclamen bed. Allow the soil to dry out between watering, without allowing the plant to wilt. If overhead irrigation is you only choice, water early in the day so foliage that gets wet can dry out before evening.  A 2 or 3 inch layer of mulch spread on the soil around the plants discourages weeds. This mulch also helps prevent evaporation of moisture from the soil and it harbors beneficial organisms to help protect plants from pest problems. The mulch will decompose over time, adding valuable organic matter and some nutrients to the soil. 


2. Fertility

Cyclamen aren’t heavy feeders in the landscape. Feed plants while they are in full growth, i.e. as long as new leaves and new flowers continue to appear. An application of a balanced controlled-release fertilizer (CRF) such as 10-10-10 or 14-14-14 with a 3-4 month formulation applied to the bed at planting will keep the plants well fed, depending on the amount of irrigation applied and the average daily temperature. Avoid over-fertilizing, especially with a product high in nitrogen, which encourages leaf growth at the expense of flowers. 


3. Disease

Cyclamen are susceptible to several diseases in the landscape. Botrytis will cause tan leaf spots on the foliage and will also affect the flower petals with water-soaked spots that later turn tan. Plants that are infected with Fusarium wilt will become very yellow. The vascular tissue in the corm will turn dark brown to black. Erwinia bacteria are responsible for soft rot, which causes the tuber to rot suddenly. The plant turns yellow, the leaves quickly wilt and the tuber may turn soft and have a water-logged appearance. This problem often occurs when the plant is planted too deep, the soil retains too much moisture, or plants are over-fertilized.  Cyclamen are also susceptible to viruses. Impatiens necrotic spot virus (INSV) will cause the flowers to be abnormal in shape. The leaves will be deformed and streaked with yellow or brown markings, or have ring spots in a thumb-print pattern. These diseases can be avoided by employing proper cultural practices:  avoiding overhead irrigation, improve plant spacing, proper air circulation, and water early in the day.


Flower infected with Botrytis


Another flower infected with Botrytis



Plant with Fusarium wilt


Symptoms of INSV on cyclamen leaf


More symptoms of INSV on cyclamen leaf



4. Insects

Cyclamen mites, spider mites and thrips can cause problems for cyclamen. Cyclamen mites and spider mites will appear when the relative humidity is low. Spider mites are tiny, but it is easy to spot their whitish webbing. Cyclamen mites are too small to be visible to the naked eye. Symptoms include yellow, curled, deformed or discolored leaves.  Thrips cause damage to the plant by piercing and sucking cells on the leaf surface. This causes silver-grey spots to form on the foliage, and striations in the flowers.  At high infection rates, the leaves may wither. Gaps in a planting can often be attributed to mice, which can eat the tubers. Remember that healthy, vigorous plants are less susceptible to pest damage than unhealthy plants.   


Typical thrips damage to foliage


Adult spider mites


5. Tips for Success

  • Cyclamen are sensitive to over-watering, plant in a bed that has a well-drained soil.
  • Cyclamen prefer cool temperatures between 55°F - 75°F, but will tolerate temperatures as low as 30°F and as high as 85°F if planted in partial-light shade.
  • Remove weeds from the plantings that compete with cyclamen for moisture, nutrients and light.