To lift or not to lift..
That is the Question.
Day 172 and still no frost.
November tasks on hold.
Reading Wendell Berry while I wait.
Usually by Firework Night, there has been a frost. On the mild inland Essex Cambridgeshire border here, it’s a welcome point of the year. Marking the proper end of the flower growing season. No way back. The tell tell sign being that dahlias are blackened. It’s quite something the first time you see it. The sappy green leaves shrink back and truly turn black rather like when basil gets caught at the back of the fridge. Gross.
The foliage would be more useful, cut back long before this and composted but it is important to wait for that frost. The plant receives that important message to stop producing buds, withdraw sugars back into the tuber and produce next seasons growth shoots there instead. Rather like leaving the messy narcissus leaves on top of the bed until they yellow, this process is important for the health of the plant and future flowers.
Of course, if you lift and compost your plants every year then this question doesn’t apply. However, if you want to take cuttings, divide or replant next year, I waver this cautionary advice; telling you to sit on your snips until we have a couple of frosts.
In the meantime you can consider whether you’ll be lifting or leaving your dahlias in position.
Until last year, I had lifted our dahlias each November. We don’t have a lot of room on our 0.4 acre plots. Leaving dahlias in position reduces the crops I can grow - there is little you can plant bar tulips (and you know how I feel about them) as a companion crop. You see in the past I broadly split the farm into 4 areas. 1. Permanent planting, trees, shrubs and perennials. 2. Rancunulus and spring biennials, early annuals. 3. Summer Annuals and 4. Dahlias. Areas 2,3 & 4 needed to over lap in a rotation. Lifting Dahlias gives me another early summer cropping space. But it’s also a lot of work. Instead, in 2021, I left a couple of hundred plants in and this summer they flowered really well. I’m going to leave them in for another season to see what happens in Year 3.
I have a theory that lifting dahlias annually, far from helping them causes more stress on the plants and certainly takes a lot more time and attention. In 2019, the lifted tubers were accidentally over watered in spring, loosing many plants to rot and crown gall. I think they are far better, if you have the soil conditions to support that, leave in position and allow the plants to engage with the soils themselves. They need less watering and can leave supports in place.
How have I managed to cope with the reduced growing space? Well, I now grow less dahlias, rancunulus and annuals. Preferring to increase the perennials and biennials that need less tending and resources to flower. Bonus is that I am growing more sustainably too and less reliant on just a few crops.
Why might you want to lift your dahlias then? Like future me in November 2023, your dahlias may well be large tubers by that point and I expect they won’t be as floriferous. Lifting will enable me to split tubers creating more plants, moving the crop into a new flowering position. You might also have heavy cold wet clay that is not great winter conditions. It could be too risky to leave the tubers in situ when they may rot.
Either way, I will label tubers with flagging tape - a stretchy ribbon like material that you can pull to rip and scribble varieties or descriptions on, tying around the bottom of the stem. Birds like to lift and toss around plant labels seemingly to play me. But maybe they hate plastic labels too. Flagging tape *usually* manages to stay on stems of dahlias regardless of whether they are in the soil or upside down in a tray drying out after being lifted. Then I have a fair game at knowing what cuttings I’ve made in the spring.
In the meantime, stems on the plants are protecting tubers from the heavy rains flooding the stems. When it does freeze, I will cut down the plants and turn over a bucket of compost or a blanket of straw to protect them from winter rains.
That is, when Mr. Tardy Frost does finally turns up.
The Braybrooke Garden in November
Walled Garden in November. Dahlias are the 3 rows are the back of the garden. All you can see is a mass of green foliage.
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