Our Beloved Dahlia

Our Beloved Dahlia

"Dahlia tubers are not like ordinary bulbs or corms. They require special attention in order to grow, but in the end, the hard work, mollycoddling and sleepless nights praying your tubers will make it through the cold/rain/slugs/snails... are all worth it."

~ Kristy, The Wildstyler


Dalia Tuber Care - The Wildstyler

Buying Tubers

Should I or shouldn't I? Well, call me crazy, but yes! Do it! The joy these blooms bring, is next level. You won't regret it. The colour they bring to your garden, those perfectly formed flowers in all shapes and sizes, and of course, the bees are happy.

Dahlia tubers in NZ are a mix of NZ grown and imported from Holland. I usually don't recommend buying from Trade Me, unless it is from a reputable seller or, you can see a photo of the exact tuber you are purchasing. There is nothing worse than spending money on a tuber for it to arrive with no neck, crown or eyes - all things that it needs to grow. The other issue with Trade Me, some people start selling their tubers far too early. If a tuber doesn't have time to harden off in the ground during autumn, it may not store well over winter. Most tubers that are dug up too early, tend to lose too much moisture in storage and shrivel. If this happens, there won't be enough energy for the tuber to sprout come spring time. It is best to wait, pre-order tubers from trusted sellers and have them delivered in spring, all ready to plant. There are many fantastic companies in NZ that provide dahlia tubers. I personally only add NZ grown tubers to my collection. There have been way too many instances of virus, gall and disease coming through in the imported tubers in the last few years. It isn't worth the risk for me. When buying a NZ grown tuber, you know that it has had at least one full growing season in NZ soil and that the grower has hopefully weeded out any that have shown signs of disease. I find NZ grown to be stronger plants. All dahlia tubers purchased from The Wildstyler have been grown this way.

When to buy?

If you are happy to store your tubers over winter, any time is fine, provided your purchased tuber was healthy and hardened off from day one. Most sellers don't except refunds on tubers that don't store well, once you have your tubers - its up to you. This can be daunting for first time growers, and with good reason. A lot can go wrong in storage... which can be the reason that tubers are sold early, to pass that stress on to someone else. People panic buy in Autumn thinking that they wont get desirable varieties later on. This isn't the case. My advice is to buy closer to Spring. 

Buying online 

Now, if you have tried to buy tubers online before, ya'll know it's cut throat. There is such a high demand that tubers are sold out in a matter of minutes. My poor ole heart can't handle the stress, but it is worth it if you get the one you want. My advice, save your payment details to your computer, because entering this info at the time of checkout is all it takes to miss out to someone faster.


Tuber Care

You can store your new arrivals in a cool, dark, dry, spot, until you are ready to plant. If they are in a bag, open the bag to let them breathe and stop any mould growing before you are ready to plant them. Dahlia tubers can make a tasty treat for rodents too, so be sure to keep them away from little critters. The dahlias may decide to sprout in the bag and thats okay. They can be planted happily with sprouts or the sprouts can be used for cuttings or cut off before planting. I usually leave mine as is, unless the sprouts look damaged, mushy or have aphids. If you have room indoors or in a glasshouse, you should pot your dahlias as soon as they arrive, in dry potting mix. DO NOT WATER. Only water tubers once they have sprouted and the sprout is at least an inch tall. A newly planted tuber has no roots so needs to develop these first in order to handle water. 


Tuber Planting

Dahlia tubers are cold sensitive and will only produce roots in optimal ground temperatures of around 15 degrees celsius. Care should be taken not to plant tubers too early in the season. If a tuber is planted before the ground temp rises, you risk losing them to rot. In New Zealand, it is recommended to start planting your tubers in late October at the earliest (depending on your location). The last few years in NZ have seen very wet spring weather. I urge you to wait until at least Labour Day, October 23rd, to plant your tubers. Yes, its exciting, but it is also heartbreaking to see a full garden bed of rotting tubers. My advice, if you want to start early, is to plant them indoors. A garage, sunroom, glasshouse, greenhouse. I plant ours indoors and do not water until the shoots are big enough (5cm). By this stage there is a heathy root system and the chance of rot has gone down significantly. In my years of doing this I have only lost around 2% of tubers, and those tubers were likely damaged already. Starting Dahlias indoors also gives you the opportunity to check them for pests and disease before planting them in your garden beds. It's really a win, win in my eyes.

Once the threat of frost has passed and the ground temp rises, plant your tubers in well draining, fertile, soil. If you don't have free draining soil, raised garden beds work a treat.

Plant your tuber 10cm deep, and at least 30cm apart from other tubers. Overcrowding can cause outbreaks of powdery mildew.

It is recommended to stake your dahlia now, in order to avoid stakes piercing tubers at a later date.

Adding a small handful of bone flour (not blood and bone) or other high K fertiliser at planting out, will give your tubers the best start. 

Bone flour - The Wildstyler


Taking Cuttings

Taking cuttings is a great way to increase your stock for summer. Take your dormant tuber and plant in shallow potting mix with the top of the tuber clump exposed. At this stage the clump/tuber does not need to be watered. Keep indoors for this process as too much moisture will rot your tuber. Your tuber should start to wake up after around 3-6 weeks. When the shoot is about 8cm long, take a knife and cut out the shoot from where it first appears on the tuber. Remove the lower leaves and pinch out the top. Dip the end in hormone rooting powder, and push into damp potting mix. Cover with a plastic bag and keep out of direct sunlight. After a few weeks, your cutting should have developed roots and will be ready for the garden once the threat of frost has passed. Be sure to protect your cuttings from slugs and snails.


 Dahlia Pinching

To get the best from your plants, it is recommended to pinch out the top of the main stem. This promotes the growth of multiple stems from just above the cut which, in turn, gives you way more flowering stems with a longer stem length. Pinch out once your dahlia has produced around 4 sets of leaves, or around 20 - 30cm tall. Don't pinch out too late. Dahlia's develop hollow stems as they get larger, which can collect water and start to rot your plant and tubers. If your tuber has produced multiple shoots, pinch them all for a beautiful, bushy dahlia with lots of flowers. 


Dahlia Labelling

There are so many ways to do this and, you can be as creative and extravagant as you like! For me, good old flagging tape is the way. Its bright, weather resistant, easy to use and cheap as chips. About $4 a roll (which lasts for ever) and available on Trade Me and at some hardware stores. Labelling tape can be used to label plants and also tubers that have been dug up to overwinter.


Dahlia Staking

Dahlias get tall and heavy, especially those dinner plate varieties. A downpour of rain can snap flower stems in an instant. Staking your blooms helps provide the support needed to bloom again and again. It is best to pop your stakes into the ground BEFORE planting your tuber. This stops the stake potentially going straight through the tuber after planting. Another way to do this is to make a grid of bamboo or use netting over your dahlias. This way the flowers grow up through the netting, which provides them with added support later in the season.


Dahlia Feeding

Once in bloom, dahlias thrive when fertilised monthly with a good balanced organic liquid fertiliser. This is especially the case if you are growing your dahlias in containers.

If adding compost, make sure it is bought from a reputable supplier and free of pesticides and herbicides. If adding animal manures, make sure these are well aged before adding.

Dahlias love Bone Flour and Organic Potash - anything high in Potassium (K). will promote beautiful blooms.


 Dahlia Flowers - The Wildstyler

Dahlia Flower Harvesting

Cut your dahlia blooms early morning or late in the evening. Dahlia aren't the longest lasting cut flower, they will usually look good for 4-5 days in a vase. It is important to harvest them at the right time of development as they wont unfurl much more once cut. So make sure they are not too closed or too open. Cut long stems and place immediately into a bucket of water. Pick your blooms every 3-4 days to encourage a constant supply of flowers throughout the season.


Collecting Dahlia Seed

A fun and exciting part of growing dahlia, is the seed! If you leave your blooms to set seed (usually best at the end of the season as your plant is winding down) you have a few surprises in store for next season. Unlike tubers, dahlia seeds will never be 100% true to their parent, so what will grow, is anyones guess. Wait until the seed head is brown and dry, give it a squeeze to check. No moisture should come out. If it is dry, cut and store - as is - in a dark, cool and dry place, until next season.

Dahlia Seedling - The Wildstyler

"At the end of last season, I collected seed from my favourite Dahlia, 'Hamilton Lillian'. This was one of the seedlings! It looks nothing like Hamilton Lilian... in any way, shape or form. I mean, I knew the seedlings were random and never like the parent plant, but I guess I expected one similarity?! Leaf colour, petal formation, I don't know? Anything really! Randomness aside, she is actually one of this seasons favourites already. The dark pink/red and black, back turned petals are everything! I love it!"

~ Kristy, The Wildstyler


Dahlia Problems

Dahlias are generally easy care provided you have the right conditions. They are prone to rot early in the season, and powdery mildew late in the season. To avoid these, watch your watering before the tuber has sprouted and plant in well draining soil. As the plant grows, remove the lower leaves of to encourage airflow and stop powdery mildew. The only other threat to your dahlias are slugs and snails.... don't get me started! These pests can decimate a garden of newly sprouted dahlia shoots in one night. You could use bait. We prefer not to do this, so I usually spend my mornings and evenings covering and uncovering newly emerging shoots with bottles that will protect from slug damage but still allow the plant to breathe. It is time consuming. Another option is to head out at dusk and pick off the little critters or, use a beer/yeast trap to catch them in. Its all very gross, but all a part of growing dahlias!

Earwigs are generally the only other pest we encounter here. They do a fair bit of damage to the blooms as they burrow in to the bud and have a snack before they open.

Other issues on the rise include crown gall and leafy gall. There is plenty of info online about these, and what to look out for. Although it isn't super common, it is increasing. Unfortunately, there is no cure for either, and plants should be destroyed - into the bin, not the compost.


Lifting Dahlia Tubers

It is recommended to lift your dahlias each year or every second year. This promotes healthy future plants for the coming seasons by keeping clumps small and stoping over crowding and preventing tuber loss through rot over the winter. Lifting can also help find pests and diseases quickly, and possibly save the rest of your garden from nasties like gall and pesky ants, who love to nest in burrowed out tubers.

Tubers can be lifted around 4 weeks after the dahlia foliage has died down, any earlier and you risk losing your tubers in storage as they haven't had a chance to harden.

Lift tuber clumps with a garden fork, not spade. I lost many a tuber in the early days due to a spade going straight through the center.


Tuber Storage

There are so many recommended ways to store tubers online. Some, I feel, are a bit over the top. Here at The Wildstyler, tubers are lifted around 3-4 weeks after the foliage has died back. If lifted earlier than this, the tubers have not had a chance to harden and will shrivel in storage. Another bonus of not lifting until then, the shorter day length kick starts tuber production. So leaving them in the ground that little bit longer, means more (and usually bigger) tubers for next season.

After being lifted, the entire clump is rinsed under the hose, left in the shade overnight to dry (not in the sun) and then placed on shelves in a cool, dark shed. Thats it! The shed has a natural airflow with small vents at the top and is secure from little rodents wanting a tasty treat. I check them every so often and give them a little squeeze, but so far have had no issues with storing tubers this way. Come spring, the clumps are divided and ready to plant. I find that clumps always store better than single tubers and there is less chance of loss. There is usually enough moisture and energy in the clump to sit out the winter, all ready for spring.


Tuber Dividing

Here at The Wildstyler, I only divide tubers before planting. As mentioned, I find the tuber clumps store better over the winter months than singular tubers do.

There are many online videos on how to divide dahlia tubers. The key things to remember - for a dahlia tuber to sprout, it needs a neck, a crown and eyes. I suggest doing a little bit of research on what to look out for before having a go on your dahlia clump. Some people use cinnamon powder on the cuts to prevent mould growing. I haven't tried this but I hear it is a great natural way to stop fungus on fresh cuts.


That's it! It seems like a lot I know, but Dahlias will give back 10x what you put in. They are the most exceptional flower and bring joy like no other. A highly rewarding (and highly addictive) garden bloom.

View the Wildstyler range of dahlia tubers here


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