How to Pick Dahlias

One of the reasons I became obsessed with growing dahlias was not only the huge range of varities but their ability to keep producing flowers from late summer right the way up to the first frost. They are the ultimate 'cut and come again' flower and the more flowers you pick, the more the plant will produce.

If you plan to pick your dahlias regularly, you’ll definitely notice more flowers if you feed them with a liquid seaweed solution once a week. I personally use the one from The Shropshire Seaweed Companyin my garden and I've linked the one that I use here.

Here are my top tips for picking dahlias:

🕐 1. Timing Is Everything: When to Cut Dahlias

Cut in the cool of the day – ideally early morning or late evening, when the plant is fully hydrated and not stressed by sun or heat.

Key signs your dahlia is ready to be cut:

• The flower is fully open (dahlias won’t continue opening once cut)

• The petals are firm, not floppy or translucent

• The back of the flower head is still tight and not browned or wilting

  
  

  🌿 Tip: Don’t be afraid to cut blooms regularly — it actually encourages more flowering.

✂️ 2. How to Cut Dahlias the Right Way

Dahlia plants will produce more flowers in a season if you pick the flowers regularly. Use a sharp, clean pair of snips or floral scissors. Dull blades = crushed stems = reduced water uptake. I can highly recommend these for their sharpness and value for money, at £6.95 for 2 pairs you can't go wrong (click here for the link!)

• Cut as far down the stem as possible, ideally just above a leaf node or set of lateral buds (those little bumps where new shoots grow).

• This is usually 20–30 cm below the flower head, depending on the plant’s size and whether you have pinched out or not. If you were brave and pinched out in July, you'll have longer stems!

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🎯 Why Cut So Low?

1. Encourages Bushier GrowthCutting high leaves a long bare stem, while cutting low pushes energy to side shoots, resulting in more bloomsover time.

2. Cut at an angle to maximize surface area for water intake

3. Go deep into the plant to encourage stronger regrowth

4. Strip off any leaves that will fall below the waterline

   
   

   🛑 Never leave leaves in water — they rot, attract bacteria, and shorten vase life.

   
   

🚿 3. Hydration Station: First 30 Minutes Are Crucial

Dahlias are heavy drinkers. To prevent stem collapse (a common dahlia downfall), you need to hydrate them fast and effectively.

Best practice for conditioning:

• Immediately place stems in a bucket of clean, tepid water

• Keep the bucket in the shade and out of wind or direct sun

• Let them rest for at least 1 hour, ideally 2–4, before arranging

🧪 4. Advanced Conditioning Tricks for Vase Longevity

Boiling Water Dip (for droop-prone varieties):

1. Boil water.

2. Pour 1–2 inches into a mug or jar.

3. Hold the bottom 2–3 cm of the stem in the hot water for 10–20 seconds.

4. Immediately transfer to fresh, cool water.

   
   

   💡 This seals the end and helps prevent air blockages that lead to stem droop.

   
   

Flower Food or DIY:

• Use shop-bought floral preservative, or…

• Make your own: Mix 1 tsp sugar + 1 tsp vinegar + 1 litre water

  • Sugar feeds the bloom

  • Vinegar inhibits bacteria

🏺 5. Setting the Scene: Vase Tips for Dahlias

• Use a sparkling clean vase (bacteria kills vase life fast)

• Avoid metal or brass containers unless lined

• Arrange with plenty of airflow between stems — cramming encourages rot

• Change water daily or every other day

• Re-trim stems every few days to keep water flowing

☀️ 6. Display Dos and Don'ts

✅ Do:

• Keep dahlias out of direct sunlight

• Place in a cool spot, away from radiators or appliances

• Enjoy the wild variation — some last 3 days, others 7+

  
  

🚫 Don’t:

• Put near fruit (bananas and apples emit ethylene gas, which shortens vase life)

• Let the vase go murky – clean, clean, clean!

  
  

💐 BONUS: Picking Dahlias for Arrangements

For long-lasting bouquets, choose:

• Ball, pompon, and waterlily types – they’re sturdier

• Blooms with a firm neck and no petal browning

• A mix of sizes for visual interest and structure

  
  

Avoid:

• Overblown dinnerplates – stunning but short-lived

• Dahlias already fading at the back or showing mold at the base

  
  

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🌟 Andie's Final Thoughts

 If your dahlias haven't flowered yet it's ok. Some varieties flower sooner than others and there will be a lot of factors that will be affecting them; the amount of water, sunlight and the soil they've been planted in. The key is to be patient and accept that it part of nature's plan - albeit we are impatient dahlia parents and just want to see FLOWERS!

Dahlias aren’t low-maintenance, but they are high reward. The secret is always in the prep and being brave - just like in life! Happy cutting, happy conditioning, and dahlia faffing ;-)