Domakihub How to Grow Dahlias: A Complete Garden Guide
From tuber to bloom — everything you need for a spectacular dahlia display.
Reviewed by Domakihub garden pros · 2026-06-23 · 5 min read
Dahlias reward even a first-time grower with extravagant blooms that run from midsummer right through the first autumn chill — perfect for cutting gardens at Greek holiday rentals or adding colour to a hotel courtyard. The video above walks through the full planting process from Longfield Gardens; this guide complements it with the exact steps adapted for the warm, dry Mediterranean climate. Follow both and you will have a garden feature that stops guests in their tracks.
Why Dahlias Work Well in Greece
Greece's long, warm summers and dry heat suit dahlias surprisingly well, provided irrigation is consistent. The key challenge is not cold winters but the intense July heat in lower-lying areas — choosing a spot with afternoon shade and watering deeply two to three times a week prevents tuber stress and keeps blooms coming from June until October.
Holiday properties and hotel gardens benefit especially from dahlias because a single planting of mixed varieties produces an almost continuous supply of cut flowers, reducing the cost of bought bouquets throughout the rental season.
Choosing the Right Varieties
For Greek conditions, ball, pompon, and cactus-type dahlias tend to perform better than dinner-plate giants because their smaller heads hold up to wind and heat without snapping. Varieties like 'Bishop of Llandaff' (red, compact), 'Karma Choc' (deep burgundy), and 'Café au Lait' (blush pink) are reliable, widely available, and hugely popular with guests for cut-flower arrangements.
If you are planting at a rental property and want low-maintenance colour, border dahlias that stay under 80 cm are the safest choice — they rarely need staking and still deliver an impressive mass of colour from a single bed.
5 Steps to Growing Dahlias Successfully
- 1
Prepare the planting site
Choose a spot that gets at least six hours of direct sun, ideally with some shelter from the harsh western afternoon sun in southern Greece. Dig the bed 30–40 cm deep and work in a generous layer of well-rotted compost or aged manure to improve both drainage and moisture retention. Sandy or heavy clay soil both need this amendment — dahlias sit in the ground for months and poor structure leads to rot or drought stress.
- 2
Plant tubers at the right time and depth
In mainland Greece and Crete, plant dahlia tubers from late March to mid-April, once soil temperature is consistently above 12 °C. Lay each tuber horizontally in a hole 10–15 cm deep with the eye (the growth node at the neck) pointing upward. Space them 50–90 cm apart depending on variety — crowded plants compete for water and airflow, inviting powdery mildew. Do not water heavily straight after planting; wait until the first shoots appear above soil to begin a regular irrigation schedule.
- 3
Stake and pinch for bushy growth
Insert a sturdy stake (bamboo or metal rod, at least 1.2 m) at planting time so you never disturb the tuber later. When the main shoot reaches 30 cm and has three sets of leaves, pinch out the growing tip just above a leaf node. This single action triggers the plant to send out four to six side branches instead of one central stem, dramatically increasing the eventual flower count — it is the most impactful thing you can do for a full display.
- 4
Water deeply and feed regularly
Dahlias need consistent moisture but despise waterlogged roots. Water deeply two to three times a week in summer, soaking the soil to at least 20 cm rather than splashing lightly every day. From the moment buds appear, switch to a low-nitrogen, high-potassium liquid feed (tomato fertiliser works perfectly) applied every two weeks. High-nitrogen feeds produce lush leaves but few flowers — the classic mistake on first plantings.
- 5
Deadhead, cut, and store tubers for next season
Remove spent blooms as soon as petals drop; every deadheaded flower triggers the plant to produce two or three new buds. For cut flowers, harvest stems in the early morning when buds are just starting to open and plunge straight into cold water. In Greece's mild coastal zones tubers can often be left in the ground over winter with a mulch cover; in colder highland areas (Epirus, higher Peloponnese) lift tubers after the first frost, allow to dry for two days, then store in dry sand or perlite in a cool, frost-free shed until the following spring.
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FAQ
- Can dahlias survive the summer heat in southern Greece?
- Yes, with two precautions: afternoon shade in the hottest months (July–August) and deep, consistent irrigation two to three times per week. Mulching around the base of plants with straw or bark chips keeps the root zone cooler and reduces water loss significantly. Avoid mid-day watering, which can scorch leaves and invite fungal disease.
- Do I need to lift dahlia tubers every year in Greece?
- In coastal areas with mild winters — the Aegean islands, Athens, the Peloponnese coast — you can leave tubers in the ground with a thick mulch layer. In mountainous regions that see frost, lift them after the first frost blackens the foliage, let them dry for 48 hours, and store in dry perlite or sand until spring. Leaving them in frozen ground causes tubers to rot.
- How do I stop aphids and earwigs from destroying dahlia buds?
- Aphids are the most common dahlia pest in Greece. A weekly spray with a diluted neem-oil solution (5 ml per litre of water, with a drop of dish soap as an emulsifier) applied early morning keeps colonies under control without harming pollinators. Earwigs hide in blooms overnight — placing upturned terracotta pots filled with dry straw near the plants traps them; empty the pots each morning. Avoid broad-spectrum insecticides, which also kill the beneficial insects that help control aphid populations naturally.