Water is essential for healthy plant growth, whether in the vegetable garden or in pots. During summer heatwaves, rain is unfortunately scarce, and watering adapted to your plants' needs and the weather conditions becomes necessary. To water correctly, a few rules should be followed. Here are our watering tips, along with a few tricks to help you water less often!
How to water your plants correctly
During dry spells, natural moisture may not be enough to meet a plant's needs, and watering becomes necessary. Your plants will thank you if you follow these few rules:
- Water early in the morning or late in the evening. Sudden watering during the hottest part of the day can shock and harm your plants.
- Avoid the cold shower: just like you, plants prefer lukewarm water. Fill your watering cans in the morning and let the water warm up during the day.
- Avoid wetting the leaves: water near the base of the plant, so the water is available where it's absorbed — through the roots. Wet leaves are also more prone to fungal diseases such as downy or powdery mildew , especially on tomatoes, zucchini, and cucumbers.
- Water is precious, don't waste it! Use rainwater whenever possible — it's not only free but also lower in salts. Your soil will thank you. Avoid broad watering with a hose and irrigate only the plants that need it. This also helps reduce weed pressure!
How to automate watering
Watering is essential, but depending on the size of your garden, it can take up a lot of time. Worse still, a single missed watering can seriously dehydrate your plants! Fortunately, there are simple and effective ways to automate watering.
Oyas
Oya for irrigating a balcony planter.
The Oyas (sometimes spelled ollas) are unglazed clay or ceramic pots buried in the soil. Their porous walls let water seep out slowly, keeping the soil around the oya moist for a long time. This helps prevent plants from drying out, even during periods of intense heat and drought. Oyas are also an excellent way to prevent waterlogged soil, since water only seeps out as needed. They help save water and water plants evenly. Learn more about oyas in our blog article: How to Water Your Garden or Balcony with Oyas?
Drip irrigation
Drip irrigation is one of the most efficient watering methods for the vegetable garden. It delivers water directly to the base of the plant, right where the roots need it, without waste. With a 30 to 50% reduction in water use compared to hose watering, it's ideal for long rows of vegetables or greenhouses. It's naturally our preferred solution here on the farm, for its convenience. Entry-level kits are available at most garden centers starting at around twenty francs — an investment that quickly pays for itself in water savings and time saved!
How much water do plants really need in summer?
The ideal amount of water depends on soil type, the species grown, and weather conditions. Potted plants, for example, dry out much faster: some may need daily watering once temperatures exceed 30°C. Here are a few practical benchmarks to adapt to your own gardening situation, seed varieties, and growing methods…
The finger test: your best diagnostic tool
Before watering, push a finger into the soil up to the second knuckle. If the soil feels moist, there's no need to water. If it's dry, it's time to act. This simple gesture helps avoid both under- and over-watering — two sources of stress for plants.
- Tomatoes: thirsty plants that appreciate regular, deep watering (3 to 5 liters per plant per week). Irregular watering promotes fruit splitting and blossom end rot.
- Zucchini and cucumbers: water generously, but avoid wetting the foliage to prevent downy mildew.
- Carrots and radishes: prefer constant, light moisture. Soil that's too dry leads to woody or misshapen roots.
- Lettuce: heat-sensitive, it can bolt quickly. Water in the evening and consider partial shade.
- Potted plants (cherry tomatoes, chili peppers, herbs): check the moisture of the potting mix regularly by inserting a finger about 2 cm deep.
To retain soil moisture, we recommend covering the soil with a layer of mulch.
Discover our accessories to make garden watering easier
Frequently asked questions about summer watering
Early in the morning (before 9 AM) is ideal: the water has time to penetrate the soil before the heat of the day. In the evening (after 7 PM) works too, but it can promote fungal diseases if the leaves stay wet overnight. Absolutely avoid watering in full sun between 11 AM and 5 PM.
The first signs of water stress are: drooping or curling leaves, cracked soil around the base, and a dull grey-green colour in the foliage. If stress is confirmed, water gradually rather than all at once.
Yes, it is one of the most documented practices in organic gardening. Several studies in agronomy have shown that a 7 cm mulch can reduce soil evaporation by 40 to 50% in the summer.
In the absence of rain and with temperatures above 28 °C, plan for 2 to 3 waterings per week for plants in the ground, and daily for potted plants. With mulching, you can often reduce this frequency by half. The best approach is, of course, to conduct your own experiments, as every garden is unique!
Learn more
- Le paillage, pour prendre soin du sol et économiser l'eau !
- Irrigation au goutte à goutte, Mémento de l’agronome, Ministère de la Coopération française, Paris 1980 T-Systems Europe S.A., 7 chemin de Novital, Z.I. la Pointe, 81150, Lespinasse (Toulouse) France.
How to water your plants correctly in summer