Step-by-Step Guide: Lifting and Dividing Dahlia Tubers


If you want to start growing dahlias, it is important to know how to lift and divide their tubers. This process is much simpler than it may seem, and it is an essential part of maintaining healthy and productive dahlia plants. Dahlia tubers can be lifted and divided in the fall, after the first frost, or alternatively in the spring before new growth begins.

The first step in lifting dahlia tubers is to carefully dig them out of the soil using a garden fork or spade. Be cautious not to damage the tubers, as broken tubers may not produce new growth. Once lifted, the tubers should be washed and dried to remove any residual soil. It is recommended to gently remove any dried roots attached to the tubers.

After cleaning the tubers, it is time to divide them. Larger tubers can be divided using a sharp knife, making sure that each division has at least 3 tuberous parts and some sprouts. Smaller tubers can be divided as well, but note that it may take them an extra year to grow into productive plants. To promote healthy growth, it is advisable to use vermiculite or a similar medium to store the divided tubers.

When planting the divided tubers, make sure to bury them in well-draining soil. The necks of the tubers should be just above the soil level, allowing the sprouts to grow out without being damaged. It is important to note that dahlias are not frost-tolerant, so if you live in an area with early winter frosts, it is recommended to lift and store the tubers.

To store the tubers for the winter, pick a cool and dry location, such as a basement or garage. Place the tubers in boxes or pots filled with vermiculite or sawdust, making sure they are not touching each other. Check on the tubers every month to ensure they are not drying out or rotting. Removing any rotten tubers will prevent the spread of disease.

By following these steps, you can ensure the health and productivity of your dahlia plants. Lifting and dividing the tubers every few years will help the plants multiply and produce more flowers. So whether you’re a seasoned dahlia farmer or just starting out, this guide will help you understand how to lift and divide dahlia tubers.

Dividing Dahlia Tubers

Dividing dahlia tubers is an important thing to do if you want to maintain healthy and productive plants. In this video, we will show you how to divide dahlia tubers step by step.

First, you need to lift the dahlia tubers from the ground. You’ve probably already done this before, but it’s worth noting that you can lift the tubers in late autumn or early winter when the plant has finished flowering and the foliage has died back. This is the best time to divide the tubers as they are dormant and don’t have any active growth.

When you’ve lifted the tubers, use a little bit of water to wash off any excess soil. This helps you see the tubers better and also prevents any soil-borne diseases from spreading.

Next, you need to assess the size of each tuber. It’s recommended to divide the tubers into smaller sections, making sure each division has at least one growing point or an “eye”. This will ensure that each new plant has the potential to grow.

Using a sharp knife, cut the tubers into individual divisions. Be careful not to cut through the tuber necks, as this can cause wounds that may lead to rotting. Also, make sure to divide the tubers in a clean and sterile environment to prevent any infections.

Once you’ve divided the tubers, you can store the excess divisions for later use. Simply place them in a cool and dry place, like a paper bag or a pot filled with sand. Make sure to label each division, so you know which variety it belongs to.

In early June, when the soil has warmed up, you can start planting the divided tubers. Dig a hole that’s deep enough to accommodate the tuber and place it in the hole with the growing point facing upwards. Cover the tuber with soil, leaving a little bit of the neck above the ground.

Now, you just have to wait for the divided tubers to grow. With proper care and maintenance, each division will produce a new plant that will then develop into a beautiful dahlia flower. Remember to water the plants regularly and provide them with enough sunlight for optimal growth.

Dividing dahlia tubers is a simple process that can greatly multiply the number of plants in your garden. Whether you’re a seasoned gardener or a beginner, dividing dahlia tubers is a technique that every flower lover should try. With a little practice, you’ll become a master at dividing these tubers and enjoy a more productive dahlia garden.

So, why wait? Start dividing your dahlia tubers today and watch your garden come to life with vibrant dahlias!

Size doesn’t Matter mostly

When it comes to dahlias, the size of the tubers doesn’t really matter, as long as they are healthy and viable. Whether you have smaller or larger tubers, it doesn’t affect the growth of the plants. However, having larger tubers can sometimes be an advantage.

Having larger tubers helps in two ways. Firstly, it provides a bigger food store for the plant, allowing it to produce more shoots and flowers. Secondly, larger tubers are easier to handle and divide, making the process of lifting and dividing dahlias much easier.

When it’s time to lift and divide your dahlia tubers, the first thing you need to do is to dig around the base of the plants and lift them out of the soil. Be careful not to damage the tubers or the roots while doing this.

Once you have lifted the plants, use a pair of secateurs to divide the tubers into separate clumps. Make sure each clump has at least one healthy tuber with some sprouts on the surface.

If you have larger tubers, you can also divide them into smaller parts. Usually, it is recommended to have at least two or three tubers per division. This will allow each division to produce a new plant.

After dividing the tubers, clean off any excess soil and inspect them for any signs of disease or rot. If you notice any issues, discard those tubers and only keep the healthy ones.

To store the divided tubers, place them in a box or a pot filled with vermiculite or dry sand. Make sure the tubers are not touching each other to prevent the spread of any potential diseases. Store them in a cool and dry place until it’s time to plant them again in the spring.

Remember that regardless of the size of your dahlia tubers, the most important thing is their viability and health. So, whether you have smaller or larger tubers, you can still enjoy beautiful dahlias in your garden.

Tuber Viability

When dahlias are grown as perennials and left in the ground overwinter, it is absolutely necessary to check the tubers for viability. Alternatively, if you choose to store your dahlias over winter, you still need to make sure the tubers are healthy before storing them.

To determine the viability of a dahlia tuber, you can follow these steps:

  1. If your dahlia mother plant needs to be divided, allow it to rest for a few days before lifting it from the ground. This will help the tubers to mature and store more energy.
  2. When lifting the dahlia tubers, use a spade or a fork to gently dig around the plant and lift it out of the ground. Be careful not to damage the tubers.
  3. Viability can be determined by checking the condition of the tubers. If they are firm and solid, they are likely viable. However, if they are soft, mushy, or have black spots, they may not be viable.
  4. If you have excess tubers that cannot be used as replanting material, you can divide them. Using clean secateurs, cut the tubers into smaller sections, making sure each section has at least one eye. This will help promote new growth.
  5. Before storing the divided tubers, allow them to dry on a well-ventilated surface for a few days. Sometimes, washing the tubers lightly can help remove any excess dirt or debris.
  6. For tubers that you plan to store, fill a container with a mix of vermiculite and peat moss. Place the tubers in the container, burying them slightly. Make sure not to overcrowd the container to allow for proper airflow.
  7. If you choose to store the tubers in plastic bags, make sure to poke some holes in the bags to allow air circulation.
  8. Store the tubers in a cool, dry place, ideally between 40-50°F (4-10°C), such as a basement or garage. Check on them periodically to make sure they are still in good condition.

Remember, tuber viability greatly impacts the success of your dahlia plants. By dividing and storing them properly, you can ensure a productive growing season ahead.

Dried out tubers

When it comes to lifting and dividing dahlias tubers, it’s important to consider the state of the tubers. If the tubers have dried out, there are a few things you can do to ensure their proper storage and potential for future growth.

1. Start by gently digging the tubers out of the soil, being careful not to damage the necks or roots. It’s best to dig around the plant and lift it out of the ground, rather than pulling on the stems, as this can cause damage to the tubers.

2. Once the tubers are above the soil, clean off any excess dirt or soil using a soft brush or your hand. This will help prevent the spread of diseases and pests during the storage period.

3. If there are any tuberous roots attached to the mother tuber, you can choose to keep them or remove them. Alternatively, you can trim off any excess roots to prevent tangling or damage during storage.

4. Take note of the sizes and varieties of the dried tubers. If you have larger tubers, these can be divided into smaller sections to produce more plants. Smaller tubers can be stored as they are or planted directly into the ground in the spring.

5. To store the tubers, place them in a well-ventilated and dry container or bag. Some gardeners prefer to store them in vermiculite or another medium to help retain moisture. Make sure to label the container or bag with the variety and date, so you know what you have and when it was stored.

6. If you notice any broken or damaged tubers, it’s best to discard them, as they may not produce healthy plants. Only store the tubers that are in good condition and free from signs of rot or disease.

7. It’s a good practice to store the dried tubers in a cool and dark place, such as a basement or cellar, where the temperature is consistent. Check on them periodically during the winter months to ensure they are not drying out or becoming too moist.

By following these steps, you can ensure that your dried out tubers are stored properly and ready to be divided and planted when the growing season starts again.

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Dr Heidi Parkes

By Dr Heidi Parkes

Senior Information Extension Officer QLD Dept of Agriculture & Fisheries.