Watering a raised bed in summer — how often, when, with what

In July there's a moment where I have to water daily. For ground beds, watering deeply twice a week beats daily shallow watering. For raised beds, that's different.

Why raised beds dry faster

The soil in a raised bed is surrounded by air on 3-4 sides. Evaporation works through all walls, not just the surface. At 30 °C and full sun, you lose around 10-15 L of water per day from a 100×100×40 cm bed — sometimes more in heat waves.

In a ground bed, soil depth buffers it. Even with a dry surface, 30 cm down there's still moisture. In a raised bed, there's air underneath too.

How often to water

Spring (April-May): every 2-3 days. Soil still cool, moderate evaporation.

Early summer (June): daily evenings, or every other morning.

High summer (July-August): DAILY in the evening. On days above 30 °C an extra morning watering may help (especially for tomatoes, cucumbers, zucchini).

Late summer (September): back to every 2-3 days.

When to water — time of day

Evening is the standard. Soil + plant absorb overnight, cooler air = less evaporation.

Morning is the second-best option. Plant is hydrated when the heat arrives.

Midday is the worst time. Water drops on leaves act like little lenses → burn marks. ~50% of water evaporates before reaching the soil.

What to water with

Rainwater: best water for plants. If you have a barrel, use it first.

Tap water: works. Very hard water makes some plants (blueberry) suffer. Most varieties don't care.

Drip line / irrigation system: saves 30-40% water because less evaporates. Worth the investment from 3+ beds.

Spot heat stress

Before a plant truly dries out, it gives signals:

• Wilted leaves at noon, firm in the evening = normal, plant doesn't pump water at peak heat. Don't panic-water.
• Wilted leaves evening + morning = real water deficit. Water immediately.
• Brown leaf edges = chronic deficit over recent days. Increase rhythm.
• Tomatoes splitting = irregular watering (alternating dry and wet). Water more consistently.

Mulch — the game changer

3-5 cm of mulch (straw, grass cuttings, bark) on the soil:

• reduces evaporation by 50-70%
• keeps soil cooler
• prevents soil crusting

I mulch in June and it saves me 2-3 watering trips per week into high summer.

My summer plan

• Early June: spread mulch
• Install drip line (or watering can + daily ritual)
• Irrigation timer for holidays (1 day = 5 L per bed automatically)
• Heat waves: shade cloth (40%) for 3-4 days over lettuce and tomatoes

In our plant library you'll find each variety tagged "drought-tolerant" or "thirsty". Stachi groups similar water needs into sensible bed sections in the planner.

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Water is the only raised-bed limitation in summer. Once you've solved it (mulch, drip, evening routine), everything else is easy.

I'm going to check on the tomatoes. They looked a bit limp at noon today — but that happens in heat. We'll see this evening.

🦔 Stachi