The great dahlia swap

Before I was a gardener, I couldn’t think of anything more boring than listening to gardeners talk about gardening. It was my No.1 least interesting topic, second only perhaps, to guys talking about cars. Now, my ears prick at a whispered plant name and I have relished finding new friends who can cope with my enthusiasm.

Gardening fever brings so many benefits, but connecting with others must be one of the best. Aside from the endless knowledge and encouragement I have gleaned by engaging gardeners, there have been many tangible benefits as well. Those that grow also love to share, particularly if they see a grateful face and a patchy plot.

The first plants I introduced to my garden were baby runners of bog sage that Mum plucked from hers. I have sedum, a snowball viburnum and irises all happily in place, reminding me of the gardens and people they have come from.
Plants, cuttings, seeds and bulbs of all variations have been both a currency and a channel for community since the first crops were raised. There is an ancient, grassroots feeling in the act of trading hand-raised produce, whether it be for consumption or planting, a practice that transcends the centuries, if anything, made easier by the arrival of technology.

Gifted, purchased and self seed dahlias are fantastic for the garden as well as the vase!

It’s my patchwork dahlia bed that reflects this gardening connection best. Of the seven or so varieties I have, only two were purchased. One late autumn day last year, my aunt dropped off a pick’n’mix bucket of her surplus tubers. Verbal descriptions and “yay-high” hand-to-leg measurements were given as an indication of what they might become.
On another visit, a great customer of our framing business arrived with three clumps of which all were well labelled, but a raised eyebrow suggested there may be some surprises. Mum delivered me a freshly dug specimen with the warning, “it has a beautiful crimson flower, but absolutely hopeless, weak stems”, something I have discovered to be accurate.
Just a few weeks ago I gratefully received a freshly dug tuber delivery from my friend’s mother-in-law who lives in Ashburton. She knew of my passion and simply did what gardeners do – connected to me with her own. This seemingly blindfolded plant-gifting would be a nightmare for those that curate their gardens closely, and even though I am fussy with my choices, given my small planting areas in the sun, a weird and wonderful library of dahlias brings a certain whimsy.

I like to grow my dahlias tightly together, with little mixing with other plants. The mass of green and dark crimson foliage looks terrific when the blooms are out, dancing above in all their strange shapes, sizes and colours. There is a real feeling of abundance at the height of flowering (and strain when you don’t keep up on watering and powdery mildew arrives).

Granted, with marginal information on the maturing size of each tuber gifted, I definitely hadn’t nailed my short-at-the-front/tall-at-the-back planting but have made notes for moving next season. In cooler climates around the world, dahlias are commonly “lifted” in late autumn, or early winter, once their foliage has died back. Due to their tenderness to frost and icy temperatures, they are cleaned, then stored somewhere dry and dark. Then, in early spring, they are commonly “divided” to create multiple, new plants, before re-planting after the estimated last frost.

My patchwork dahlia bed!

In New Zealand, it is quite common for people to not lift their dahlias, instead insulating them with some good mulch in the colder regions. However, soggy ground is as destructive as the cold, so those in wet regions might choose to lift to protect from rot.

While commercial growers begin advertising and selling tubers online now, these are as “orders” which will be delivered in spring. Growers will wait to divide their large clumps of tubers, just before sending out orders. It’s home gardeners that are likely to lift, divide, gift, then store or replant in early winter. Regardless of swapping or gifting, it is a brilliant idea to do this every few years to multiply your own garden stock and to check for rot and disease.

Dahlia tubers are really odd-looking “storage organs”. When dividing, or receiving tubers to plant, these will only be a success if a small nodule called an “eye” is evident. This can be found at one end of the tuber, where it has grown from the main stem of the clump. While this is tricky to explain, I would highly recommend searching on YouTube for some filmed examples. The eye is equally important for those that are dividing for the first time, recognising that although a clump from a single plant will feature many tubers, when separating with a sharp blade, it is only the ones with an eye that will be able to mature as new plants.
I tend to hedge my bets, often planting small clusters of tubers, rather than dividing further to singles if I am unsure if there is an eye on each separate unit.

A mish mash of surprises from gifted dahlia tubers

My favourite “purchased” Dahlia is “Shiloh Noelle”

If you are lucky to be on the receiving end of tuber presents this season, you can pop them away until spring, giving yourself some valuable time to think about position. I however, will pop mine in now, resting horizontally with the eye facing up, about 10–15 cm deep in the soil. I’ll then get them cosy with an additional layer of mulch to help protect them from any frosts that may occur here in coastal Christchurch.

In early spring, I will sweep that layer back to be sure they don’t get soggy as it warms up and – ultimately – just cross my fingers for a healthy specimen, If you haven’t ventured into giving dahlias a go, say yes to the next offer and enjoy the sensational beauty they can bring to any sunny corner of the garden.

This article was first featured in my Stuff ‘Homed’ gardening column for beginners , The Press, Dominion Post and other regional papers on June 17th 2021
All words and images are my own, taken in my home and garden in Christchurch, New Zealand.