Autumn care of dahlias and preparation of tubers for wintering
Autumn for me is dahlias. Mine begins to bloom in June, and all summer the neighbors peek at me through the fence, recalling that I promised them some tubers or seeds by the fall. In September, a tart note appears in the aroma of these flowers, hinting at the approaching cold. So, it's time to start preparing plants for a long cold winter. In this article, I will share my secrets of autumn care for perennial dahlias and their preparation for winter storage.
What dahlias grow on my flower beds
Dahlias, I think, are very unpretentious plants. They do not require a special feeding scheme and calmly tolerate short-term drought. But there is one “but” - they are very afraid of the slightest minus temperatures.
I grow both perennial dahlias and summers, whose seedlings are planted annually. Usually I choose 2-3 new varieties to plan long-tier flower beds and create a pleasant variety in front of the house.
I really love seed bags marked “mix”, as well as the following varieties:
- "Nurdviks Gloria";
- "Tiger cub."
It is worth considering: tall varieties of annual dahlias begin to bloom later than miniature species.
Of the perennial dahlias, I prefer peony, spherical and pompom varieties:
- “Downham Royal”;
My annual dahlias in the fall do not cause any trouble. You do not need to dig and store them in the winter. But perennial care must be taken. Sometimes late flowers are “caught” by morning frost. He is not yet afraid of the tubers, but already hints at their timely movement into the storage box.
About 1.5 months before digging up the tubers, I begin to carry out a gradual preparation for their wintering. It includes several stages.
Features of autumn care for dahlias
Dahlia rhizomes are powerful, dense and quite voluminous. They accumulate moisture in themselves as an untouchable reserve for possible drought. To avoid decay during storage, they require forced drying through a gradual reduction in moisture.
For the formation of the last buds and full photosynthesis, 1 watering per week is enough. 7-10 days before digging up the tubers, I completely stop watering.
Cleaning around the bushes
One of the conditions for good plant health is the timely removal of fallen leaves and faded parts. In well-caked residues, various pests feel at ease. The danger lies in the fact that in the fall they begin to actively dig into the ground in search of a warm place for the winter. They consider rhizomes of dahlias as an excellent opportunity to winter "on everything ready". Do not give them the slightest chance!
To do this, simply remove the plant debris, thoroughly dig the soil around the bushes and shed the earth with a weak solution of potassium permanganate. The measure is also effective against fungal infections, which also multiply rapidly in the conditions of autumn humidity. The deadline for carrying out such work is 2 weeks before digging up tubers for winter storage.
No top dressing!
The main part of fertilizers for dahlias is applied in spring and summer. The nitrogen component prevails for abundant flowering and the formation of tall lush bushes. However, it is impossible to deprive a plant of phosphorus and potassium substances. They are necessary to increase immunity, the accumulation of strength for the next season.
At the end of July, I last water my dahlias with infusion of mullein and a solution of wood ash, and then I spend one top dressing with potassium sulfate at the rate of 30 g per 1 plant. Lignohumat, Normat-L, Argolan, and Agricola also work well.
Keep in mind: after (approximately) August 10, fertilizers are no longer applied, otherwise the tubers will be poorly stored.
Digging and rejecting tubers
Too early to cut the stems and dig up the rhizomes is not worth it. As long as there are green leaves and the weather is favorable, plants still accumulate nutrients.
Winter bookmarks vary by region. In the Volgograd region, for example, this time does not begin before October. Very rarely, frosts fall in late September. If there is a suspicion of a change in weather, I cover the bushes with a film or a layer of spunbond at night (depending on what is at hand).
From the end of August, I begin to huddle bushes every 2 weeks to protect the roots from sudden frosts. After flowering, I cut the stems to a height of 12-15 cm from ground level, sprinkle with mulch.
Important: on the bushes when pruning, you need to fix the tags with the name of the variety, if you plan to plant them not mixed, but according to a certain plan.
As soon as the first frosts started, you can start digging tubers. For this, I choose a dry sunny day, preferably without wind. Carefully digging up a bush from all sides and holding for the trimmed stumps, I simultaneously lean on a shovel. The tubers come out completely without damage and incisions.
The most crucial moment is a picky inspection and rejection of diseased or damaged tubers. At the slightest suspicion of a fungal infection or the presence of a pest in the tuber pulp, I set it aside. If there is enough material for the next year, then all the defective parts are burned.
In my experience, treating them by cutting and soaking in drugs is almost useless. I immediately dispose of the affected bushes with a lump of earth, and I spill the bed with any fungicide. I also reject plants that did not produce a single bud, weakened and with too thin stems. Next year they will not be of any use from them either.
Processing of tubers before storing
This is where the neighbors who asked for dahlias during the summer usually wait for me. For experienced gardeners, I immediately cut off the secrets with the secateurs. For those who have been engaged in floriculture recently, please wait and do the tuber processing on my own.
- the roots are cleared of the earth, if it does not show off well, then I wash it in a bucket or basin with cool water;
- secateurs I divide segments immediately after removing them from the ground;
- for disinfection, immerse the material in a weak solution of potassium permanganate for 40-45 minutes;
- as an alternative to potassium permanganate, you can take drugs "Maxim" or "Hom", eliminating fungal infections and preventing the development of rot;
- for a day, the material is laid out for drying in a shady well-ventilated place (it is impossible to dry near a heating system or a working oven);
- for better preservation of dahlia rhizomes, I make them a paraffin coat, dipping the tubers one at a time into the molten and slightly cooled mass of paraffin.
I know that many gardeners sometimes use chicken protein for these purposes, but I have never tried it, because I store blanks in the cellar, and sometimes mice appear there. For me, paraffin is safer.
Only after carrying out these works I give the promised planting material along with a note with the name and description of the variety. I wrap the remaining tubers in several layers of newspapers and put them in a wooden box. Between the rhizomes, I definitely leave a little space so that air circulates freely.
Storage conditions for dahlias tubers
The main indicator that must be maintained during storage of dahlia tubers in winter is the level of humidity. In dry air, planting material will dry out very much and lose its germination ability, in too humid conditions, rot will begin or mold will appear. The optimal indicator is 60%. I do not specifically calculate anything, because I just drop the boxes into the cellar, after etching it for the winter from mice.
The temperature there is kept within + 4 ... + 6 ° С, in the spring it starts to rise gradually to + 10 ° С. It’s time for dahlias to wake up, so that everything happens naturally.
For several years now I have been able to successfully preserve dahlias during the winter, and in the spring again admire their luxurious flowering, which I sincerely wish you.