Air flow and the benefits of aeration on tomato plant leaves

Air Flow and Tomato Plants

We could all do with a gentle breeze when the weather is hot! However, tomato plants need plenty of air movement to help keep them from disease and to help them absorb the nutrients they need.

Here are a few of the benefits:

  • Good airflow reduces condensation and the risk of fungal disease both in the greenhouse and outside.
  • Leaves also dry more quickly in a gentle breeze.
  • Plants perspire (transpire) a bit like humans but through their leaves. This enables them to replace moisture and nutrients through their roots.
  • Good aeration encourages evaporation of moisture through leaves, and therefore, increases moisture and nutrient uptake.
  • Slight movement caused by good airflow encourages strong stems.

When Sowing Too Early

One of the big problems with sowing too early is that plants become leggy and have stems that are too thin. A gentle breeze created by a fan, if growing indoors or in a greenhouse, helps to prevent leggy seedlings.

Disease and Insect Attack

Also, if plants are too close together or have lots of wet decaying leaves around their base, the lack of airflow will leave them exposed to fungal attack and it’s a good place for insects to gather and lay their eggs.

Remove decaying and yellow leaves from around the base of both tall and bush varieties to allow the air to circulate

Helps Absorb Carbon Dioxide

Tomato leaves need to absorb carbon dioxide from the air around them. Without a good airflow, their intake of carbon dioxide is reduced and plants will grow more slowly.

So, get the air circulating, keep your plants healthy and watch them grow!

See Also: Condensation and Tomato Plants


6 Responses

  1. Rhys Jaggar
    | Reply


    One thing of interest about ‘leggy’ tomatoes. I just planted out 4 Shirley plants which were my least vigorous, most leggy ones, into the garden as a first experiment of trying to grow outside.

    Although they’ve not grown hugely upwards, they’ve lost their legginess and thickened up really nicely and are flowering well on the first truss.

    Given the rain we are getting, I am worried we may have a blight issue this year. So I tried a comfrey tea watering today (both in the ground and for my potted plants) to see if that beefs up their ‘immune systems’.

    I’ll let you know what happens: if what I’ve read is true, it should do well. Reality is always slightly more complex!

    • Nick
      | Reply

      Hi Rhys,
      There seems to be no end to the rain, at least where I am. A few more days of this and tomato plants grown outside will be in trouble.
      I look forward to the results of your comfrey tea experiment.

      • Rhys Jaggar
        | Reply

        First result of comfrey tea experiment was astonishing: the Tumbler plant’s tomatoes swelled up radically almost overnight. I have about 30 tomatoes growing now with plenty more flowers. We’ll see how they do.

        Difficult to say whether the same happened on the Alicante, but there are about 10 fruit growing now – it certainly didn’t do them any harm. I have one fruit on one Shirley plant – next three weeks look critical in terms of fertilisation and fruit set.

  2. Avril
    | Reply

    Hi Nick,
    Regarding Aeration – Should I remove any lower branches/leaves on Tumbling Toms and Red Alert.
    We’ve had lovely hot weather up here in Scotland and it’s all to change tomorrow. I am concerned about cold damp conditions.
    Having only grown tall varieties, I’m not sure if you should remove lower branches on tumbling/bush varieties.
    Thank you

    • Nick
      | Reply

      Hi Avril,
      I like to remove any leaves that are resting on the soil surface or are turning yellow. This keeps things tidy and allows a little more air around the base of the bush varieties.

  3. Rhys Jaggar
    | Reply

    No problem with this the past 3 days, Nick: we have the NW London equivalent of a Sirocco, a Santa Ana wind blowing! By trial and error, I’ve found the only place in the garden where the sun shines and the wind is a gentle breeze, not something which bends the tomatoes downward.

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