Digging up the dahlias

The time has come, the days are short, the mornings are frosty, christmas is fast approaching, it’s time to dig up the dahlias. I’ve had mixed feelings about dahlias over the years. For a while I thought they were old-fashioned and terribly dated with their showy saucer-sized over the top flowers or their ridiculous pom-pom flowers atop a tall stem, now however I can’t get enough of them. I think they are fabulous! Bringing the borders to life towards the end of the summer when everything else is past its prime the dahlias light up the garden standing tall in the sunshine until the first frosts.

Well I don’t know about your garden but mine has been hit with a couple of stiff morning frosts already and even some snow flurries and with the temperatures predicted to decrease even more next week the time to deal with these crowning beauties is now. My dahlias are in large plastic pots that allow me to move them around quite easily. I can pop them into place in the garden into empty spots when other summer perennials are past their prime and at the end of the season it also means that I can move them into the garage to over-winter them. Dahlias are tubers which rot magnificently if left in the ground in our wonderful clay soil. If they are planted in the ground it is essential to lift them for the winter. Cut the stems down to about 10 cms from the level of the soil, gently lift the tubers and rinse them off; this will allow you to see any damaged or dead tubers and discard them. I turn them upside down for about a week to let them dry out completely and then line a plastic crate with newspaper covered with a layer of clean, dry compost from the garden centre, after that I pop the tubers on top and keep them in a cool dark space for the winter. It is really important to keep the tubers apart, if one set starts to rot the others will be safe, if they are all together in a jumble the whole lot will go off and you’ll have to start from scratch next year. Check on them sporadically over the winter, if your storage area is heated you may have to spray the compost with a spritzer bottle to prevent the tubers from drying out completely.

Agapanthus are another delicate plant that really should be over-wintered under cover. I also keep these beauties in pots and transfer them to the garage for the winter. They do not like to have wet roots so if left outside they too will rot and you’ll be left with nothing in the spring. Agapanthus are greedy feeders and perform best here when they are in pots, have very good drainage, and are fed every week until they flower. In pots they are very happy to be tightly packed, I repot mine about every 3-4 years.

For the winter make sure you lift any terracotta pots with little supporting feet or make your own feet with scraps of wood or flat stones from the garden. It is essential that pots have clear drainage over the winter. Pots left sitting directly on terraces or balconies have a tendency to freeze to the ground, the water remaining in the soil also freezes and expands putting pressure on the pots. While this may be ok for one winter if you continue to leave them without feet the pots will eventually shatter leaving shards of terracotta everywhere creating a big mess.

If you have any tender perennials in pots they need to be wrapped in horticultural fleece for the winter. This can be found at all local home stores and garden centres, many now even stock christmas-themed jute bags to pop over your plants. Any tender perennials in the ground should also be well mulched to protect the roots. This little protection will allow for a good start to the growing season.

I have as good as closed up my vegetable garden for the year. I’ve been taking leaves from the two kale varieties I planted earlier in the year “nero de toscana” and “scarlet” and they continue to perform well. The romaine salad is almost finished so I will soon have to resort to buying my salad very soon. For the winter I have some newly planted spinach which I’m hoping will continue to put on a little growth before things get too cold and the herb bed of course continues to provide tarragon, chives, sage, rosemary and mint. The red onion sets are beginning to break through the soil and they will stay nicely in the ground until the spring when they will really take off.

In as much as is possible try to keep off the lawn. With our clay soil often drenched with moisture following any rain the pressure of your footsteps compresses the ground making it more difficult for the lawn to looks its best in spring. If you notice a well worn passage it may be time to consider laying a path or putting in some stepping stones.

Don’t forget to switch off and drain your outdoor water taps and wind up your drip irrigation systems, frozen pipes and damaged drip hoses do not make for a happy gardener.

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