How To Reduce Chances of Blight in Your Greenhouse or Polytunnel

BlightBlight EpidemicBlight can really decimate your tomato crop and indoors grown tomatoes can be particularly prone to this pesky problem. This is a fungal problem and the spores can linger for years, causing perpetual problems. Keeping on top of cleanliness and order in your indoors growing space will help to minimise blight problems, as will removing any plants that are suffering immediately and disposing of the material to prevent the spread. You cannot entirely escape the risk in the wet British summer but you can reduce the chances of losing your whole crop. Here are some ways to reduce the chances of blight hitting the tomatoes you are growing in your greenhouse or polytunnel:


Polytunnel doors openKeep Your Greenhouse or Polytunnel Well Ventilated


Open the doors on hot days, employ adequate shading and try not to over plant as this can reduce air flow. Even when it is grey and dull, you will usually still have to leave doors open for ventilation at this time of year.


Take Care When Watering To Keep Leaves Dry


When you water your tomato plants, try to make sure that you water close to the soil and roots, where the water is needed, rather than getting the leaves all wet. When leaves are wet, blight is more likely to take hold.


Water In The Morning


Water will usually splash a little and it is difficult to avoid wetting foliage entirely. To minimise the risk of the leaves staying wet overnight, you should do your watering in the morning if possible, to allow things to dry out before the temperatures drop at night.


TomatoesRemove Leaves Below Lowest Fruit Truss


You can decrease the risk of blight taking hold by increasing ventilation around your tomato plants. This can be achieved, when the fruits are setting this month, by removing the lower leaves of each plant. You should aim to remove leaves up to the lowest fruit truss.


Feed Tomato Plants With High Potassium Not High Nitrogen Feeds


It is important to feed tomato plants in order to get good fruits. You should always feed with a high potassium feed, not a high nitrogen one because a high nitrogen one will encourage leafy growth at the expense of the fruit and leafy tomato plants are more susceptible to blight.


Remain vigilant at this time of year and as we move from summer into autumn and, should you be unlucky enough to have a problem with blight, act quickly. If you do this you should be able to avoid a complete disaster.

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