How to protect your dahlias from frost | Gardening

Quite a few areas around Portsmouth have not had a frost yet.

However, here at Waterlooville we had a nasty one a week ago and although I was hoping the frost had not killed the dahlias – it has.

The stems, leaves and flowers have all turned brown and that really is the end of another summer.

This damage has brought back fond memories of my childhood.

My dad grew lots of dahlias and he always told me they would be killed off by frosts before bonfire night. He was right.

We always allowed the stems to dry off and then used them on the bonfire to lighten the night sky in our garden. Wonderful memories. I had a lovely mum and dad.

Some varieties of dahlias seem to be hardier than others.

To explain: If you left dahlias in the ground last winter and they grew again last spring, these would appear to be hardy.

However, if you bought new varieties, they will have produced lovely tubers (swollen roots) but if left in the ground they may become frozen during the winter and they won’t grow again next year.

But we can save them and here’s what to do.

Cut the stems down to just four inches above the level of the soil. Cut the old stems into short pieces and put them into the compost heap.

Now dig out the tubers and wash off all the soil. Make sure you do this on a nice day. There’s nothing worse than doing it in the rain.

Then tie a label on to the stem. If you cannot remember the name, put the height and colour on the label. You’ve no idea how pleased you’ll be next year that you have adopted my labelling regime!

Leave the tubers in the sun (yes, we do occasionally have a glimmer of sunshine at this time of year) for a day and then put them into the compost from a growing bag which you used for tomatoes, covering the tubers with two inches of compost.

If there any signs of rings of brown downy mildew on the stems, puff on some sulphur powder. This will stop the fungus spreading.

The tubers are best kept in deep trays. There are some used for mushrooms and these can often be found at the market – just ask the bloke if you can have some.

Keep the tubers in a frost-free place all winter and keep the compost dry.

At the end of February, sprinkle water on to the compost and as long as the weather is warm, new shoots will appear.

Great! We are off to another brilliant summer and dahlias are one of the best flowers for displays from early July right up until the autumn frosts strike.

Dahlia flowers were really good this summer and they provide ground cover all through the summer.

Let’s hope they will be just as good as ever.

Have faith, they will!

Jobs for the weekend

As there is less foliage in the garden there appear to be more cats. Buy a pot of garlic paste and dip six-inch-long sticks into the paste so three inches of paste is on the top of the sticks. Push the sticks into the ground. Cats hate the smell of garlic.

Check there are no rotten nuts in the bird feeders. Rotten nuts kill blue tits.

Please put water out for the birds.

Plant seeds of early peas in cells in the cold greenhouse, only two pea seeds in each cell, using the 24 cells which fit into a standard seed tray. No heat needed, just make sure they are in a place where mice can't get them. Keep them on the dry side otherwise they will rot. Be careful not to give them too much water.

Save for a soil warming cable for the greenhouse or buy one as a present for the gardener in your life for Christmas.​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​

If fencing posts have to be renewed, look at Metpost fixings, it makes the job a lot easier. Postmix is easy to use.​​​​​​​

Question time

Q: I read your article a few weeks ago when you told us to start cyclamen tubers off again. I repotted mine but the leaves are tiny and the leaf stems seem far too long. What have I done wrong?Celia, Horndean.

A: This is etiolation. The plants need a lot more light but not bright sun. The leaves will be larger within a month and you won’t notice the long stems. A mirror set up so light is reflected will help.

Q: I put broad bean seeds in cells in my greenhouse and something has disturbed the compost. HV, Rowlands Castle.

A: Rats and mice can play havoc. Buy poison and put it in a dish nailed to the floor. If the bait disappears, you have a rodent. When the bait remains, the rodent is dead. To stop it happening again. Use two upturned plastic buckets with a shelf across the buckets’ bases. Mice can’t climb the sides of a bucket.