Tiarella

Culture Sheet

Growing Temperature:

50-65° F

Holding Temperature:

40-50° F

Soil PH:

5.5-6.5

EC (What is EC?):

1.5-2.0 pour through method

Fertility:

Tiarellas are light to moderate feeders, requiring only modest fertility levels. Fertilize at a rate of 75-100 ppm.

For Controlled Release or Slow Release Fertilizer, see your preferred supplier for recommended rates for incorporation or top dressing, as it varies by fertilizer.

Vernalization:

Not required for flowering but help to produce a more bulked plant. If a heavy flowering plant is desired in the spring it is best to plant in late summer and allow plants to go dormant for the winter months.

Pests & Diseases:

Root and crown rots caused by the pathogens Phytopthora, Pythium and Rhizoctonia are sometimes a problem. Tiarellas are most susceptible to these pathogens when they are overwatered or when grown under cool conditions. Botrytis is another disease that could be problematic. Provide adequate air circulation to avoid this disease. Powdery mildew and rusts are also sometimes an issue.

The primary insect pests are aphids and whitefly.

Potting & Timing:

To obtain full, flowering Tiarellas for spring sales, it is beneficial to plant them during late summer of the previous season. You will be rewarded with more blooms on fuller plants.

Moisture:

For potting soil use commercial planting media.
Provide Tiarella with even moisture. They do not tolerate overly wet conditions, which may lead to Pythium or Phytophthora. Additionally when they are kept too moist over an extended period of time, the foliage may become slightly chlorotic. Once established they can tolerate a slight dry down between irrigations.

Planting Level:

Plant with the top of plug at soil level.

Lighting:

Grow them in 55% shade in the north and 80% shade in the south.