A worm’s eye view on Dahlias

If you find this useful, download the latest version of our pdf guide HERE. Or read through the page below. Where, at the the foot of this page I have added useful links for further reading.

As we grow our Dahlias we will update this page …

double page spread on dahlias and types of dhalias
cold frame

The Wrigglers are Amateur Gardeners. This is our guide to Dahlias. You can download the pdf, or read this page.

Why a guide on Dahlias?

With a little knowledge, sunshine and support dahlias will flower all summer long, for years to come. All you need to do is choose the type of dahlia you like, and one that suits your space. You can grow them from seed, tuber or from a basal cutting.

download a pdf of this guide

Where to start?

There are thousands of varieties, you can categorise them from the following types. You can grow dahlias from seed’ tubers or basal cuttings. Start your Dahlias indoors in March’ April’ or wait to plant in the soil in May.

  • Cactus, Semi-Cactus Dahlias
  • Pom-pom and Ball Dahlias
  • Waterlily Dahlias
  • Collarette, Decorative and Anenome Dahlias
  • Single Dahlias

The single dahlias is the most attractive to pollinators.

download a pdf of this guide

pdf double page spread talking about the range of sizes dahlias come in, with a  dahlias to do list

Our dahlia list

  • Plant out when all risk of frost has gone
  • Keep 60cms apart, dahlia’s like their space
  • Unless a compact variety, stake them and tie in their shoots every week
  • Limit five stems per tuber
  • When stems reach 40cms, pinch out the top two sets of leave
  • For more flowers, feed them every two weeks with a high potash feed
  • Tie them in, did we say that?
  • Regularly pick the flowers or deadhead the plants for a longer flowering season … right up til the first frosts

download a pdf of this guide

Potting tubers

Starting tubers indoors, under glass – basically away from the cold damp garden soil and frosts. Here’s what we did:

  • Plant up your tubers in pots – 3 litre about 18cms wide
  • Use damp soil’ not wet. Too much water will rot the tuber
  • Label the pots – or leave it to memory!
  • You could see shoots in 3-6 weeks’ time, depending when you planted them

download a pdf of this guide

Potting up tuber layout for pdf - double page spread
A diagram Showing the frame parts of a cold frame being put together
  • Dahlia seed progress - week 1
  • Dahlia seed progress week 3
  • Dahlia seed progress week 5
  • Dahlia seed progess
  • Dahlia seed progress week 6
  • Dahlia seed progress week 7

Progress of our Dahlia Mignon seeds

We sowed these seeds end of January. They germinated in a few days. I will keep a visual diary of the progress here.

I used a propagator box on the windowsill till the seeds germinated and then removed the lid. Since then I have kept the plants in a tray on a windowsill.

For a test, I transferred two plants into a cold frame outdoors to see the difference in growth. They are doing well outdoors, but not as well as the windowsill cousins.

download a pdf of this guide

Potting up tubers

The tubers arrived in the post at the end of February. I potted up half of them. This slideshow will show the progress.

I have read a lot of articles and watched videos on potting up dahlias, and after care. There are different thoughts and ideas in all these articles. Here are the links:

Three acre dahlia growers: video

Starting Dahlias for summer – from gardener’s world. Watch the Alan Titmarsh video.

Amateur gardening’s web article on planting Dahlias with step by step images

RHS growing guide for Dahlias

You can download a pdf of this guide if useful here

  • potting up dhalia tuber 'Playa Blanca'
  • potting up dhalia tuber 'Playa Blanca'
  • Added soil to cover potting up dhalia tuber 'Playa Blanca'

Dahlias like

Dahlias like free-draining soil, in full sun

Dahlias dislike

Strong winds and cold, wet soil

The wet rots the tubers. The cold, sub-zero temperatures kills them too. Quite simply, they’re not hardy.

Which is why a lot of gardeners dig tubers up after the first frost, and store them. To replant them once more in spring.

download a pdf of this guide

Good to knows …

Tips, if you like:

  • You can plant tuber from the size of an AA battery
  • Keep an eye on the weather, if a storms coming, or heavy rain forecast don’t plant your dahlia tubers – they hate wet soil. Wait for a dry spell.

download a pdf of this guide

This is a double page spread of a pdf on dahlias. This page highlights some good to knows. You can plant tubers from the size of an AA battery, to don't plant out if heavy rain is forecast, tubers will rot if sat in water
A diagram Showing the frame parts of a cold frame being put together
This is a double page spread  of a  pdf on dahlias. This page talks about maintenance care - For more flowers and a healthy plant follow these regular maintenance tips: 1. Limit each bulb to five stems 2. When plants reach about 20 cms' feed them every two weeks with a high potash feed – this will produce more flowers 3. Pinch out stems at 30-40 cms 4. Unless a compact variety (30cms)' stake them and tie in their shoots every week 5. Water weekly. One heavy watering rather than lots of surface watering 6. Tie them in' did we say that? 8. Regularly pick the flowers or deadhead the plants for a longer flowering season ... right up til the first frosts

Some ongoing Dahlia maintenance to follow:

  • Limit each bulb to five stems
  • When plants reach about 20 centimetres, feed them every two weeks with a high potash feed – this will produce more flowers
  • Pinch out stems at 30-40 centimetres
  • Unless a compact variety (30 centimetres)’ stake them and tie in their shoots every week
  • Water weekly. One heavy watering rather than lots of surface watering
  • Tie them in’ did we say that?
  • Regularly pick the flowers or deadhead the plants for a longer flowering season … right up til the first frosts

download a pdf of this guide

Don’t forget …

To produce bushier Dahlias’ and more flowers’ remove all but five of the shoots sprouting from a tuber.

It’s not just us who love Dahlias, garden pests do to. The usual culprits, slugs and snails … but also earwigs. Try dispersing with an organic method … stuff some straw or paper into a small pot, upside down on a bamboo stake. They crawl in there on a hot day, for you to get rid of as you see fit.

download a pdf of this guide

This is a double page spread from a pdf about growing dahlias. It summarises the pdf, don't forget To produce bushier Dahlias' and more flowers' remove all but five of the shoots sprouting from a tuber. It finishes with a section and cartoon on pests, especially earwigs
A diagram Showing the frame parts of a cold frame being put together

For an expert’s eye on pruning:

RHS Pruning groups

Understand the groups and you understand when, how and which plants to prune.

These groups are designed to offer gardeners a general guide on how to prune a tree, shrub or climber.

LINK


Pruning is one of those grey areas for me. The info here is not only fun to read, but will save some of my plants from an overly keen secateur-wielding gardener, like me.

Simon Haynes


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Can worms prune? Yes they can!