Division | Plant Care Topic Guide

What Is Division?

Division is a horticultural technique used to propagate plants by separating their roots or stems. This method is commonly used for plants that produce offsets, suckers, or stolons, such as hostas, daylilies, and strawberries. The underlying botanical science behind division involves the manipulation of plant hormones and growth patterns to stimulate the production of new roots and shoots. By dividing plants, gardeners can increase their stock, share plants with friends, and improve the overall health and vigor of their plants.

Division is an important technique for plant health because it allows gardeners to control the size and shape of their plants, improve soil quality, and reduce the risk of disease. By dividing plants regularly, gardeners can prevent them from becoming pot-bound, which can lead to reduced growth and increased susceptibility to disease. Additionally, division can help to improve soil structure and fertility, which can lead to healthier and more resilient plants.

The process of division involves carefully digging up the plant, washing away the soil to expose the roots, and then separating the roots or stems into individual sections. Each section should have at least one growing point, such as a bud or a shoot, to ensure that it will produce a new plant. The sections are then replanted in a new location, watered well, and provided with adequate light and nutrients to promote growth.

Tools and Materials You'll Need

• A sharp, sterile knife or garden fork
• A bucket or container for washing away soil
• A watering can or hose with a fine spray nozzle
• A pot or container with good drainage for replanting
• A well-draining potting mix specifically designed for the type of plant being divided
• A fertilizer specifically formulated for the type of plant being divided, with a balanced NPK ratio of 10-10-10
• A thermometer for monitoring temperature, with a range of 65-75°F (18-24°C)
• A hygrometer for monitoring humidity, with a range of 40-60%

Step-by-Step: How to Perform Division

1. Water the plant thoroughly the day before division to make the soil easier to work with, aiming for a soil moisture level of 20-30%.
2. Dig up the plant carefully, using a fork to loosen the soil to a depth of 12-18 inches (30-45 cm) and a width of 2-3 times the diameter of the plant.
3. Wash away the soil from the roots using a gentle stream of water at a temperature of 60-70°F (15-21°C), taking care not to damage the roots.
4. Separate the roots or stems into individual sections, making sure each section has at least one growing point, and trim any damaged or diseased roots with sterile pruning shears.
5. Replant the sections in a new location, using a well-draining potting mix and a container with good drainage, and water thoroughly with 1-2 cups (250-500 ml) of water.
6. Provide the newly divided plants with adequate light, with a photoperiod of 12-14 hours, and nutrients, with a fertilizer application rate of 1-2 teaspoons (5-10 ml) per gallon (3.8 L) of water.
7. Monitor the plants closely for the first few weeks after division, keeping the soil consistently moist but not waterlogged, with a soil moisture level of 15-25%, and providing supplemental lighting if necessary, with a light intensity of 10,000-20,000 lux.

Best Practices and Pro Tips

• Timing is Everything: Divide plants during their dormant season, when they are less stressed, typically between October and February in the Northern Hemisphere, or between April and August in the Southern Hemisphere.
• Soil Quality Matters: Use a well-draining potting mix with a pH between 6.0 and 7.0, and a nutrient content of 10-10-10 NPK, to promote healthy root growth.
• Water Wisely: Water the plants thoroughly after division, providing 1-2 cups (250-500 ml) of water per plant, and keep the soil consistently moist but not waterlogged, with a soil moisture level of 15-25%.
• Provide Adequate Light: Provide the newly divided plants with adequate light, with a photoperiod of 12-14 hours, and a light intensity of 10,000-20,000 lux, to promote photosynthesis and growth.
• Monitor Temperature: Keep the temperature between 65-75°F (18-24°C) during the first few weeks after division, to promote root growth and establishment.

Quick Reference Table

Best Plants for Division

Some of the best plants for division include Hostas (Hosta spp.), Daylilies (Hemerocallis spp.), Strawberries (Fragaria x ananassa), Peonies (Paeonia spp.), Irises (Iris spp.), and Grasses (Poaceae). These plants are all relatively easy to divide and can be propagated using this method. The Hosta, for example, is a popular perennial plant that can be divided in the spring or fall, and can be replanted in a location with partial shade and well-draining soil. The Daylily, on the other hand, is a versatile plant that can be divided in the spring or summer, and can be replanted in a location with full sun and well-draining soil.

As we explain in our Repotting guide, division is an important step in maintaining the health and vigor of plants. Which we cover in detail in our Fertilizer article, the right nutrients can make all the difference in promoting healthy growth. See our Pruning guide for a deeper look at how to prune plants after division to promote healthy growth and prevent disease.

Common Mistakes to Avoid

• Dividing Too Frequently: Dividing plants too frequently can lead to stress and reduced growth, with a decrease in plant height of 10-20% and a decrease in leaf size of 5-10%.
• Not Providing Enough Water: Failing to provide enough water after division can lead to moisture stress, with a decrease in soil moisture level of 10-20%, and reduced growth, with a decrease in plant height of 5-10%.
• Dividing at the Wrong Time: Dividing plants at the wrong time, such as during periods of extreme weather, can lead to reduced growth and increased susceptibility to disease, with an increase in disease incidence of 10-20%.
• Not Providing Adequate Light: Failing to provide adequate light after division can lead to reduced photosynthesis and growth, with a decrease in plant height of 10-20% and a decrease in leaf size of 5-10%.
• Not Monitoring Temperature: Failing to monitor temperature after division can lead to reduced growth and increased susceptibility to disease, with an increase in disease incidence of 10-20%.

What is the Success Rate of Division?

The success rate of division can vary depending on the type of plant, the time of year, and the care provided after division. However, with proper care and attention, the success rate can be as high as 80-90%, with a survival rate of 70-80% after 6 months.

What is the Best Season for Division?

The best season for division depends on the type of plant and the climate. In general, spring and fall are the best times for division, when the weather is cooler and there is ample moisture, with a temperature range of 40-70°F (4-21°C) and a humidity range of 40-60%.

Is it Mandatory to Water the Plants Thoroughly After Division?

Yes, it is mandatory to water the plants thoroughly after division, providing 1-2 cups (250-500 ml) of water per plant, to prevent moisture stress and promote healthy growth, with a soil moisture level of 15-25%.

What is the Best Way to Provide Aftercare for Divided Plants?

The best way to provide aftercare for divided plants is to keep the soil consistently moist but not waterlogged, with a soil moisture level of 15-25%, and provide adequate light, with a photoperiod of 12-14 hours, and nutrients, with a fertilizer application rate of 1-2 teaspoons (5-10 ml) per gallon (3.8 L) of water.

How Do I Troubleshoot Problems with Divided Plants?

To troubleshoot problems with divided plants, check the soil moisture level, with a range of 15-25%, and adjust the watering schedule accordingly. Also, check the light intensity, with a range of 10,000-20,000 lux, and adjust the lighting schedule accordingly. Finally, check the temperature, with a range of 65-75°F (18-24°C), and adjust the heating or cooling schedule accordingly.