Q&A for How to Grow Dahlias in Pots

Strip it down to about 5 growing stems. Remove the lower leaves in July to help air circulation and feed with tomato food once a week (at half strength). Don't allow too many buds. If you want loads of flowers you will need a rich, well drained compost and regular feeding.

Dahlias usually bloom about 8 weeks after planting. If it's been longer than that, your plant might not be getting enough sun. Make sure it gets about 8 hours of direct sunlight daily. If you didn't fertilize it, apply a low-nitrogen, high-phosphorus fertilizer. As for dead-heading, removing spent flowers encourages the plant to sprout new buds.

You can bring it in, but I don't expect it to flourish and bloom indoors because of the dry air and short days. After a frost kills the top, let it sit for a day or two to allow the moisture to drain into the tubers. Then cut off the dead stuff, but leave a bit of stem attached. You can bring the entire pot indoors, into a cool, dark area. Only water occasionally during the winter to keep it from becoming bone dry. Better yet, you could unpot it and shake off the soil and let it dry. Then put it in a paper bag in a cool, dark place. The idea is to keep it dormant until it can go outdoors next spring. Check it about once a month in winter, and if it seems too dry, soak it in a pail of water for a few minutes and then let it dry again.

If you plant them outside in May they will be flowering by the middle of June. However, different varieties flower at different times.

No. The first growing flower is atop of the first growing stem. Nipping the tips makes for a more compact plant with side stems, and allows harder stems to form. There is a trade-off -- you lose your best first flowers, and the main plant then throws smaller buds.

Most likely you're either under- or over- watering them. If they're drowning in water, gently pour some of the water out. If they're dry, water them more!

It sounds like the plant is very dry and needs water to prevent this again. I would just cut off the damaged leaves and buds to right below the damaged stem or stems.

They like well drained soil, so provided they have this and the roots do not sit in water they can be treated just like any other plant.

Definitely. Oak trees are known to be excellent for Dahlias. Always plant them in close proximity.

Yes, but include plenty of slug pellets, and plant them into the borders as mature plants just before flowering.

Gently pinch it off with your fingers or clip them with a clean pair of pruners.

Try to provide more water and make sure the greenhouse is not too hot. If they still do not bloom, they might be dead.

That happens from improper soil or insect diseases, so check those aspects first.

I would advise using pesticides in this instance, purely because dahlias have no need to be organic.

I tried more than one tuber in each (15-20") pot last year and was disappointed. There were fewer flowers and generally scrawny stems. I'm going back to one in each this year.

A dormant period is much better as it allows the tuber to rest.

No need to waste all your work like that, maybe something is wrong with your soil. Try placing them in places with more sunlight, do some more drip irrigation and moisturise your plant more evenly, keeping the foliage dry as possible, or buying a different type or brand of soil.