Dahlias for Sale

The golden rules of dahlia growing are to keep them free from frost, plant them in the sun with support, then feed them well, keep them free from pests and either cut them often, or deadhead them early. Do these six things, and your reward will be a constant supply of popping flowers from July to November or so.

Dahlias are tender Central American plants. A light frost will cut down the plant and probably damage the tuber, and a hard freeze will kill it. So, remember to lift the tubers for storage before winter comes, pot them up, and keep them in a sunny room, greenhouse or conservatory until after the last frosts. Plant them out again promptly so that their roots establish well. 

Plant in good, thoroughly prepared soil, enriched with well-rotted compost, in a sunny spot with good drainage. Making a low raised bed is a good tactic on heavy clay. Fill it with a mix of compost, leafmould, worm castings and something like coconut coir to retain moisture; break up the clay a bit underneath the bed, but don't try to mix the compost blend down into it - worms will take care of this over time.

Water Dahlias well, they are thirsty beasts, and feed them with diluted tomato feed from June onwards. Taller varieties need solid stakes, bamboo canes will do for the rest, and it is best to drive these in at planting time. Strong garden twine, wrapped around several times, especially the tall, decorative "dinner plate" dahlias, will secure them nicely. Many low plants can help to cover up dahlia legs, lavender loves the same sunny, well drained conditions.

Earwigs are the dahlia grower's number one enemy but as they also eat huge numbers of greenfly, we suggest trapping them rather than using poison. Fill little pots with newspaper, dry grass or straw and put them upside down on bamboo canes amongst your dahlias. Empty the traps wherever you have greenfly, or as a public service, onto roadside Lime trees (Tilia species).

For the biggest flowers for the show bench (or just because size always matters), pinch off all buds on a stem except for the main one. Alternatively, for a balance of bigger flowers and filling up your vases around the house, reduce the number of buds on a stem to two, three or four. If your garden display is the most important thing, then leave them be and just deadhead them as soon as they begin to fade.

Cut flowers for vases in the early morning. Cut horizontally with secateurs right above a set of leaf nodes and side buds. Try to cut flowers when they are 90% open; dahlia buds don't open much after cutting.

When you've brought them inside, hold the stems underwater and make a fresh cut across the bottom, keeping the ends underwater from now on so that no air gets in, and put them directly into a container with about 6 or 7cm of really hot, not boiling, water for at least one hour. Cut off leaves that'll be underwater, as for any plant going in a vase. Keep their base in water at all times to prevent air entering the vascular systems (phloem and xylem).
Change their water every day and add solutes to it: you can buy these ready-made, or make your own florist's brew: a little squirt of lemon juice, a pinch of sugar (ideally fructose), and one drop of bleach. You're coaxing the flower into thinking it's still alive with a shot of energy, while preventing bacteria from taking advantage of the situation. By the time the flower runs its natural course, it is in a low level state of embalming, with no bacteria inside its vascular systems, preserving its appeal a little while longer.