RPS x MOTHERS DAY - Dahlia seed starting

Robertson Garden Club
May 7
2 min read

We are pleased to share this knowledge in conjunction with Robertson Public School as a part of their Mother's Day seed gifting.

The wet paper towel method is a great seed-starting hack. It’s perfect for checking germination rates, saves on potting mix, and gets your seedlings off to a healthy start with minimal mess. Here's how to do it:

When to start your seed?

Seeds are best started in August/September. Seedlings shouldn't be planted out into the open until after the last frost. The 1st weekend in November is usually a safe bet.

Why Start Dahlias from Seed?

Dahlias are most often grown from tubers, but starting from seed is a fun and rewarding way to discover new flower forms and colours — especially if you’re a fan of open-pollinated varieties like the stunning single or collarette types. Plus, seedlings can bloom in their first season!

What You’ll Need

Dahlia seeds
Paper towels (plain, unscented)
Ziplock or plastic sandwich bags, or you a dinner plate with gladwrap
Spray bottle or water
A warm, bright spot

Step-by-Step Instructions

1. Moisten the Paper Towel

Dampen a paper towel with clean water using a spray bottle. It should be moist but not dripping. If it's too wet, give it a gentle squeeze.

2. Place the Seeds

Lay your dahlia seeds on half of the paper towel, spaced apart so they aren’t touching. Fold the towel over to cover them.

3. Seal

Place the folded towel into a labelled ziplock bag or plastic container. Write the date and variety on the bag with a marker so you can keep track.

4. Provide Warmth

Place the bag in a warm spot (ideally 20–24°C / 68–75°F). A sunny windowsill, top of the fridge, or a seedling heat mat works well.

5. Check Daily

Open the bag every day to check for germination and allow a bit of fresh air in to prevent mould. Seeds usually germinate within 5–10 days.

6. Pot Them Up

Once you see roots and tiny shoots, gently transfer the sprouted seeds into seedling trays or small pots filled with quality seed-raising mix. Handle carefully by the seed shell or leaves—not the root. Using a toothpick is helpful for lifting gently.

7. Grow On

Keep your seedlings in a warm, bright spot and water gently as they grow. Once they’re big enough, harden them off before planting out into the garden after the risk of frost has passed.

Bonus Tips

Not all dahlia seeds will germinate, so start a few more than you need.
Avoid placing the towel in direct sun if it causes condensation and overheating.
Use a fungicide spray or sprinkle of cinnamon if mould becomes an issue.

The paper towel method is a simple, low-cost way to start dahlias from seed and works especially well if you’re limited on space early in the season. Whether you're hoping for a rainbow of new colours or just experimenting with seed-grown dahlias for the first time, it's a rewarding way to dive into dahlia season.

(To read their full in depth article please visit their site here )

Happy growing!