Domakihub How to Plant a Window Box That Thrives All Season
Everything you need to choose, fill, and plant a beautiful window box from scratch.
Reviewed by Domakihub garden pros · 2026-06-23 · 5 min read
A well-planted window box adds instant colour and kerb appeal to any Greek home, holiday rental, or hotel balcony — and it takes only an afternoon to set up. The video above walks through the installation and planting process step by step; the guide below breaks down the key decisions so you can adapt them to your climate and setting. Whether you are refreshing a Santorini villa or brightening an Athens apartment balcony, the same core principles apply.
Why Window Boxes Work So Well in Greece
Greek summers are long, bright, and dry — conditions that push many plants hard, but which trailing Mediterranean varieties such as pelargoniums, portulaca, and million bells absolutely love. A window box concentrates the impact: even a single 60 cm planter filled with bold colours can transform the exterior of a rental property and lift guest photo ratings overnight.
Window boxes are also one of the lowest-cost, highest-return upgrades for property owners. Unlike landscaping, they need no groundworks, can be changed each season, and can be taken down if a tenant requests it.
Choosing the Right Box and Compost
Material matters in a warm climate. Terracotta looks authentic and breathes well, but dries out fast — fine if you can water daily, but a liability for a holiday property that sits empty mid-week. Fibre-glass or quality resin boxes hold moisture longer and weigh far less, making them safer for shallow brackets. Whichever material you choose, drainage holes are non-negotiable: standing water is the fastest way to kill roots.
For compost, use a peat-free multi-purpose mix blended with roughly 20 percent perlite or coarse grit to aid drainage. Add a slow-release granular fertiliser at planting time and you will barely need to feed again for three months. In Greece's heat, moisture-retaining granules (such as water-absorbing polymers) mixed into the bottom third of the box can cut watering frequency by almost half.
How to Plant a Window Box: 5 Steps
- 1
Mount the box before you fill it
An empty box is light; a filled one can exceed 25 kg for a 90 cm planter. Fix your brackets to a solid wall stud or use masonry anchors rated for twice the expected load, and check that the box sits at a very slight forward tilt so water runs to the front rather than back into the wall. Only once the bracket is secure should you start filling.
- 2
Add drainage material and compost
Cover the drainage holes with a layer of crocks, gravel, or broken terracotta pieces — about 3 cm deep — to stop compost washing out. Fill two-thirds of the box with your perlite-blended multi-purpose compost and firm it lightly. Leave at least 3 cm of headroom from the top of the box so water does not splash over the edge when you irrigate.
- 3
Plan your plant arrangement before you plant
The classic formula is 'thriller, filler, spiller': one tall, eye-catching plant in the centre or at the back (e.g. a burgundy cordyline or tall snapdragon); compact bushy plants in the middle to fill the volume (e.g. petunias, impatiens, or herbs); and trailing varieties at the front edges to soften the box and cascade downwards (e.g. bacopa, lobelia, or ivy geranium). Lay the plants on top of the soil still in their pots and step back to check the composition before committing.
- 4
Plant, firm in, and water thoroughly
Remove each plant from its pot, gently tease the rootball if it is tightly bound, and set it into a small hollow in the compost at the same depth it was growing in the pot — do not bury the crown. Fill gaps with extra compost and firm around each plant with your fingers to eliminate air pockets. Water the whole box slowly and deeply until water runs freely from the drainage holes, then allow the surface to partially dry before the next watering.
- 5
Set a watering and feeding routine
In a Greek summer, window boxes in full sun may need watering every day, sometimes twice. Push your finger 2 cm into the compost: if it feels dry at that depth, water now. Feed with a liquid tomato or high-potash fertiliser every two weeks from early summer onwards to keep flowers blooming rather than the plant putting energy into leaves. Deadhead faded blooms every few days — this single habit, more than any other, keeps a window box looking lush for months.
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FAQ
- Which plants survive a hot Greek balcony in full sun?
- Pelargoniums (zonal and ivy geraniums), portulaca, million bells (calibrachoa), petunias, and lantana all thrive in direct Mediterranean sun. Avoid impatiens and fuchsias in full summer sun as they will scorch — save them for north-facing or shaded spots.
- How often should I water a window box in summer in Greece?
- Once a day is the minimum for most boxes in July and August; south-facing terracotta boxes may need a second watering in the evening. A simple drip-irrigation timer connected to a nearby tap is a worthwhile investment for holiday rentals where the property may be unoccupied mid-week.
- Can I grow herbs in a window box instead of flowers?
- Absolutely. Basil, oregano, thyme, rosemary, and flat-leaf parsley all do well in a sunny window box and have the added bonus of being useful in the kitchen. Mix in one or two colourful edible flowers such as nasturtiums to keep the display attractive for guests.