Dahlia Care Tips for Winter Dormancy

Dahlias are beautiful, bold, breathtaking—and totally worth their big reputation. Now that it is winter though it is only natural that even the showiest blooms need a little R&R. Here’s how to care for your dahlias during their dormant season so they can bounce back better than ever next year and reward you with an overflow of spectacular blooms (provided you have cared for them well and fed them after flowering of course). Here's your Dahlia Care Tips for Winter Dormancy.

First Things First: Can You Leave Them In the Ground?

Good news! If you live in most parts of South Africa, your dahlias can stay right where they are over winter. The climate’s kind enough—as long as:

• The soil drains well (they hate soggy feet).

• You don’t get severe frosts—being that they’re from the wonderfully warm land of Mexico, they hate being cold even more. 

• You mulch them with compost. 
  
  

 Mild frost?  No problem.
 Frozen soil?  That's when you'll need to step in and do some lifting. 

Lifting Tubers – The Ultimate Retreat

If your garden does experience frosty tantrums, it's safer to  lift your dahlia tubers  for the winter.

When?

Do it  at the start of winter , once the plant has stopped flowering, the leaves look like they have seen much better days and basically when they have weathered away. 

How?

1. Cut the stems down to  about 5 cm above the ground .
   
   

2. Grab a  garden fork  and gently lift the tubers.
   
   

3.  Shake off the soil . 
   
   

4. If you see any damaged tubers,  tear them away from the crown  (that’s the old stem part).
   
   

Dust and Dry your Dahlia 

Now that you’ve got them out:

•  Dust them with fungicide  to prevent nasty moulds.
  
  

• Let any cuts or damage  dry in a shady, airy place . Not in the sun—sunbathing is so last season.
  
  

 Don’t wash them.  This isn’t a bubble bath; too much water = rot.

Name That Tuber!

Before you forget who’s who:

•  Label each tuber  with their variety name.
  
  

• Tie a tag around the stem (or the “neck”).
  
  

Don’t rely on memory—trust us, next spring all tubers look the same.

Storage: Keeping Tubers Happy Through Winter

Once they’re dry and labelled, pack them carefully  into a box (cardboard works great).

1. Surround each tuber with something dry and comfy like:
   
   

   • Sawdust
     
     

   • Vermiculite
     
     

   • Shredded newspaper
     
     

   • Sand
     
     

   • Wood shavings
     
     
     

2. Store the box somewhere:
   
   

   • Dark 
     
     

   • Dry 
     
     

   • Frost-free 
     
     

   • Not warmer than 20°C 
     
     

Think of it as a quiet holiday cottage for tubers. No parties. Just peace and chill for four months before their rave growth cycle comes late spring. 

Propagation: Splitting the Growth

Want more dahlias? (Silly question—of course you do.)

Once you lift and clean your tubers, look for big, bulky crowns. You can divide them:

• Make sure each piece has at least one old stem.
  
  

• You’ll see little “eyes” (tiny growth points). These are next season’s shoots. Don’t poke them!
  
  

• Leave a few tubers on each split so they have energy to grow.
  
  

Dust them with fungicide again, and store just like you would whole ones.

Uninvited Guests: Pests and Problems

Dahlias, like all celebrities, attract pests:

•  Aphids and thrips  are the main culprits. They carry viruses like tiny flying syringes. Ew.
  
  

• If a plant looks  mottled, stunted or weirdly curled , it might be infected. Best to  discard  those plants to protect the rest.
  
  

During their full growth spurt, dahlias are mostly tough cookies. However, near the end of the season,  fungus might show up , especially if it’s humid and air circulation is poor.

• Thin the lower leaves to  let them breathe .
  
  

• If things look seriously fluffy or fuzzy, go ahead and  spray  with a fungicide.
  
  

Don't panic about late-season mould—it’s like the end of a costume party. The foliage was leaving anyway.

In Summary

• Leave them in the ground if your winters are mild.
  
  

•  Lift and store  if it gets frosty or soggy.
  
  

• Always  label ,  dust ,  dry , and  store  in something dry and breathable.
  
  

•  Split big clumps  for more plants, but be kind to the “eyes”.
  
  

•  Treat pests early  and don’t tolerate viruses.

There you have it, Dahlia Care Tips for Winter Dormancy and a detailed guide on exactly what to do when your darlings need their beauty sleep. 

If you would like to order dahlia tubers, our preorder for them and other wonderful summer bulbs is coming soon. Mark your calendars for 11 July. Deliveries start in early October. 

Happy Gardening!