Warm glow if dahlias spared freezing cold
This year, for the first time, a friend planted a few dahlia tubers in a border, in April, but the results have been very disappointing.
His big mistake was because he was in a hurry to plant but dahlias struggle in cold soil. The ground temperature should reach 60°F before the tubers go into the earth. So he should have waited until the threat of frost had passed and then gone ahead and prepared for months of colour.
Some gardeners start tubers indoors in containers to get a jump on the season but don’t be in a hurry to plant. Patience is the key.
Select a planting site with full sun. The more sun there is, the better dahlias grow – producing more blooms for longer.
Dahlias thrive in rich, well-drained soil. Large varieties and those grown solely for cut flowers are best grown free from competition from other plants. Dahlias of medium to low height mix well with other summer flowers.
If you have just a vegetable garden, it’s the perfect place to put a row of dahlias for cutting. Tubers planted in five-inch pots of decent compost and then kept warm and watered will soon produce shoots which promise superb late-season colour.
Harden off young plants before planting them outside when the threat of frost has finally vanished and then pop them into well-dug soil enriched with manure and perked up with a dose of general-purpose fertiliser.
Once buried a few inches in their final homes and watered well, just let them grow. As they inch higher, tie them to their stakes.
If you want huge flowers, remove all but the central bud; if you want a mass of blooms, pinch out the shoot tips.
When the first frost blackens the leaves, cut the stems to 8-10 inches and dig up the tubers and the soil surrounding them and pop them away in a shady, frost-free spot for a few days.
Prepare a shallow box with a mixture of garden soil and sand. Clean the tubers and put them in the box. Then cut back the stems to an inch or two and store the boxes somewhere frost free and out of direct light – between 35 and 50F.
Examine the tubers every few weeks, discarding any that have become soft or mouldy. The healthy survivors can be replanted in spring after the frosts have passed.