1. Home
  2. Expertise
  3. Diseases & Pests Advice
  4. Pansy / Viola

Pansy / Viola

Pansy X-Large Flowered: Colossus™, Mammoth™

Pansy Large Flowered: Delta™, Karma™

Pansy Medium Flowered: Mariposa™, Sky™

Viola Series: Penny™, Rocky™, Endurio®, Patiola®

 

1. Soil and pH Needs

Pansies are tolerant of a wide range of soil conditions, but prefer a rich soil with good drainage. 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 between 5.6- 6.2 for optimum uptake of iron; 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. The frequency of watering will depend on the type of soil, weather conditions and the amount of mulch. Mulch will not only reduce soil water evaporation but will also reduce splashing of water onto the lower leaves, moderate soil temperatures and reduce weed competition. 

 

2. Fertility

Pansies and violas expend a great deal of energy during their short life cycle. Their rapid growth fosters the need for regular fertilization. Applying a granular fertilizer every six weeks with a 1-3-2 ratio will keep them blooming and healthy. Since pansies and violas are grown in the late fall/winter and early spring it is recommended not to use a slow release (polymer coated) fertilizer. During that time of year, slow release fertilizers break down too slowly, resulting in low fertility levels and poor growth.

In high pH soils (alkaline soils) additional iron or iron sulfate may be beneficial to reduce chlorosis (yellowing) of the foliage.  Yellow foliage on pansy/viola may also be caused by a nitrogen deficiency within the plant. Both can be corrected with the proper supplemental fertilizers. 

 

Symptoms of Iron deficiency in pansy

 

3. Disease

Pansies and violas are susceptible to several fungal diseases. Cercospera leaf spot is the most common foliar disease. It can be identified by small, purplish spots that first develop on the older leaves where they eventually expand into conspicuous, purplish-black spots with a distinctive feathered appearance. Anthracnose is a common leaf spot disease on pansies/violas and is associated with plants under stress or those with root rot. Its distinguishing characteristics are tan leaf spots with thick black margins. The third major disease is Botrytis which is often detected on the flowers. It is identified by small, pinprick-type lesions and bleached out areas on the flower. Infection starts on the petals and can ultimately consume the entire flower. Irrigating correctly can prevent most of the fungal diseases. Provide water early in the day to allow for plants to thoroughly dry, and utilize drip irrigation when possible.

 

Cercospera leaf spot

  

Anthracnose

 

Botrytis on pansy flower

  

4. Insects

There are three pests which may harm pansies/violas. Aphids are tiny soft bodied insects that cluster on the growing tips of leaves and flower stems, sucking plant juices. The plants become stunted and deformed. Spider Mites are tiny pests that also feed on plant juices. Pansy leaves will turn yellow and eventually drop off. Slugs are worm-like pests that feed on plant leaves and stems, often at night. Remember that healthy, vigorous plants are less susceptible to pest damage than unhealthy plants.  

 

Aphid infestation on pansy stem

 

Slug damage on pansies

  

5. Tips for Success

  • If pansies/violas fail to thrive it is often due to a lack of water.
  • Pansies and violas need at least six hours of sun.
  • Deadheading (removal of spent flowers) will prolong bloom time and help produce a fuller plant.
  • Remove weeds from the plantings that compete with the pansies/violas for moisture, nutrients and light.

Information provided by Syngenta Flowers