SEPTEMBER in the Dahlia Patch

It's still pretty chilly but it's time to start thinking about tubers! Hopefully things will start to warm up soon which means we can start thinking about waking up some of tubers if you wish to take cutting from them to expand your crop and also starting some seedlings if you have a greenhouse of protected spot for them.

Dahlia seedlings

If you’re looking to multiply your dahlias, taking cuttings from tubers is one of the most effective methods. This guide will walk you through the process of waking up dahlia tubers, encouraging shoots to form, and how to take cuttings from them for propagation.

Step 1: Waking Up Dahlia Tubers

Before you can take cuttings, the dahlia tubers need to wake up and start producing new growth. This process mimics the natural progression that occurs in spring, encouraging the tubers to sprout.

Materials Needed:

• Dahlia tubers

• Shallow tray or container

• Potting mix

• Light water sprayer

• Plastic wrap or lid

• A warm location

Instructions:

1. Check the tubers: Before anything, inspect your dahlia tubers to ensure they are healthy. Look for firm, plump tubers with no signs of mold, rot, or excessive dryness. A tuber should have at least one viable "eye" or growth node, typically located near the neck or crown of the tuber.

2. Prepare the tubers for sprouting: Place the tubers in a shallow tray or container. You can either lay them on a bed of slightly moist potting mix or directly on the tray. Some gardeners prefer lightly covering the tubers with soil to maintain moisture.

3. Provide warmth and humidity: Place the container in a warm spot (around 15-20°C) with indirect sunlight. You can cover the tubers with plastic wrap or a lid to maintain humidity, but make sure there’s some ventilation to prevent mold growth. Spritz the tubers lightly with water occasionally to keep them from drying out. Some growers also use a seed heat mat to really speed up the process. This can be purchased inexpensively from places like eBay, Amazon etc.

4. Wait for sprouts to form: Within 2-4 weeks, you should start seeing small shoots or "eyes" forming. These are the beginnings of the new growth from which cuttings will be taken.

   
   

Step 2: Taking Dahlia Cuttings

Once your dahlia tubers have sprouted and the shoots are a few inches tall, you’re ready to take cuttings.

Materials Needed:

• A sharp knife or pruning shears

• Rooting hormone

• Small pots or trays

• Seed-starting mix or light potting mix

• Clear plastic bag or dome (optional for humidity)

Instructions:

1. Select the right shoots: Look for healthy shoots that are 3-4 inches tall. You’ll want to select the strongest, most vigorous shoots, as these will have the best chance of rooting.

2. Make the cut: Using a sharp, clean knife or pruning shears, cut the shoot just above where it emerges from the tuber. Aim to include part of the tuber tissue with the cutting if possible, as this helps improve rooting success.

3. Prepare the cutting for rooting: Remove any lower leaves on the shoot, leaving only the top two or three leaves. Dip the cut end into rooting hormone, which encourages faster and stronger root development, though this step is optional.

4. Plant the cutting: Fill small pots or trays with a well-draining seed-starting mix or light potting mix. Make a small hole in the soil with a pencil and insert the cutting, pressing the soil gently around it.

5. Provide warmth and humidity: Place the pots in a warm location with indirect light. To maintain humidity, you can cover the cuttings with a clear plastic bag or dome, ensuring there’s adequate airflow to prevent rot. Mist the soil lightly if it begins to dry out.

6. Wait for roots to form: In 2-4 weeks, your dahlia cuttings should begin to develop roots. You can check by gently tugging on the cutting—if you feel resistance, roots have likely formed. Once the roots are well-established, you can transplant your new dahlias into larger pots or directly into the garden when the weather warms up.

Step 3: Caring for Your New Dahlias

Once rooted, your new dahlia plants should be treated like any young plant. Here are some tips to ensure they thrive:

• Transplant carefully: After your cuttings have rooted and the weather is frost-free, you can transplant them into your garden or larger pots.

• Water regularly: Keep the soil moist but not waterlogged, ensuring that the young plants have consistent access to water as they establish themselves.

• Feed your plants: Once the cuttings have started growing well, consider feeding them with a balanced, water-soluble fertiliser every couple of weeks.

Propagating dahlias by taking cuttings from tubers is a simple and rewarding way to expand your collection. By following these steps to wake up your tubers and carefully take cuttings, you’ll soon have a host of new dahlia plants ready to brighten up your garden!

Dahlia from last season. Variety: "Mystic"