A bit of rain won't hurt the plants. Blight arrives via fungal spores travelling on the breeze. If they're around, they will infect the foliage wet or dry. In other words, covering them from rain won't stop infection.
Italophile I have seen articles from respected professional gardeners that say Late blight is caused by the Phytophthora infestans fungus and affects both tomatoes and potatoes. It is especially dangerous if the weather is particularly cool and wet. Late blight was the fungus that caused the Irish Potato famine. The leaves will have lesions and will appear as irregular gray spots. If the weather is damp a white mold may appear around the spots. Once the tomato fruits become infected they will develop dark regions that will cover a large percentage of the tomato. The fungus may be spread tomato plant to tomato plant by wind or rain.
One of the most severe tomato diseases affecting home gardeners, early blight can affect the stems, leaves, and fruit of tomato plants. It can also cause damping-off in seedlings. It doesn't occur in arid dry regions but is most active in warm, wet or rainy conditions.
Plant symptoms: Brown circular "bull's eye" rings appear as 1/2-inch diameter leaf spots. The spots appear first on lower, older leaves. As the disease progresses, stems and fruit may become infected. Leaves turn yellow and wither, starting at the base of the plant, until the whole plant is affected.
Fruit symptoms: Similar to the leaf spots, the spots on fruit appear as dark brown concentric rings with the presence of dark, dusty spores. As the disease progresses, the spots on more mature fruit may appear larger, dark, dry, and sunken.
Causes of Early Blight
The fungus survives in infested soil and plant residue. Therefore, planting successive years in the same soil can cause a recurrence of the disease. It is caused by different fungi than late blight. The disease can be carried by infected seed and can be spread by wind, water, insects, humans, and equipment. The spores that land on plants will affect the leaves when they are wet.
The Alternaria fungus is most severe on plants stressed by a heavy load of fruit or low nitrogen fertility and is worse during the rainy season.
Control of Early Blight
A combination of practices can help keep the fungus under control. The best method is prevention. Once it's started the disease is very difficult to control. Fungicide may be your only option.
Preventative measures:
Rotate your crops by not planting tomatoes in the same soil where tomatoes, peppers, potatoes, eggplant have been planted for at least two years.
Stake and mulch tomato plants to keep foliage from contact with the soil.
Plots surrounded by grasslands are better protected because grasses don't host the disease.
If watering from overhead, do it early in the day to allow the sun to dry the leaves.
Use disease-free certified seed.
Use fresh deep soil with good drainage.
Sterilize the soil with hot water before planting.
Inspect tomato seedlings before planting and destroy any that show disease signs.
Increase the amount of organic matter in the soil. In particular, well rotted manure will increase fertility and decrease nematodes.
Use "green manure" nitrogen fixing legumes in the off-season to increase fertility of your soil for tomatoes.
Chemical control:
First check with your county agricultural extension office for their recommendations and to find out what chemicals are legally allowed.
When early symptoms of the fungus are detected, apply protectant fungicides (carbamates, clorotalonil, and cuprics) to the entire plant.
Use intervals of seven days if the conditions are wet or ten days if the weather is dry.
Rain or overhead irrigation will wash off the fungicide treatments so fungicide will have to be reapplied.
For more information on the Alternaria fungus and other tomato diseases, contact your county Extension office.
That's mostly all true, Christopher, though their advice to spray after you find early symptoms of Early Blight is crook. The only effective spray technique is preventive - before the spores arrive. Once leaves are infected, there's no killing the spores apart from removing infected leaves and destroying them.
Late Blight is a lot, lot less common in domestic gardens. Early Blight is probably the most common domestic fungal problem, along with Septoria Leaf Spot.
My point was only that covering the plants won't protect from infection. Won't even reduce the chances. While damp foliage can be an incubator, the spores will still infect dry foliage. I see it every season. I get zilch rain in summer, have very low humidity, and still end up with Early Blight.
I decided to just put them out today I erected supports made from canes and in total put about 20 plants in the garden. As we have a break in the weather I was thinking now is a good a time as any. I still have 15 plants in reserve and they will replace any casualty's. It took me all day to get it done but its done now I just hope they survive. They are best out where they can get the sunlight and nutrients they need. My Amish paste are not as strong as the Black Russian they seem a weaker plant but they have all germinated and ill slip them in when i think they are strong enough. I may have to give a few plants away as I have room for maybe ten or so more as I don't want to give up too much room but that all depends on how my outdoor ones cope
Widespread ground frost forecast by the Met Office for next weekend
UK Outlook for Saturday 3 May 2014 to Monday 12 May 2014:
"....Most areas fine and dry with sunny spells this weekend, although there is a risk of a few light showers in the east on Saturday whilst some northwestern parts may turn cloudier with patchy rain on Sunday. Cold overnight, with fairly widespread ground frost, but daytime temperatures around average so not feeling too bad in sunshine. The mainly settled conditions look to persist through the early part of next week, temperatures then probably rising a little above average with the risk of overnight frost reducing. Northwestern parts, however, may remain cloudier with a risk of rain at times. Thereafter, most likely a return to slightly more unsettled conditions, particularly for western and northern areas, with near average temperatures and still a risk of colder interludes affecting the north at times...."
Gardening in Central Norfolk on improved gritty moraine over chalk ... free-draining.
Ill have to cover them then I have some polythene coming tomorrow. But I honestly cant see a frost where I am. It was supposed to be a colder and a rainy day today
Yegh Ill cover them for sure but I cant see a frost but if we do have one I have plants in reserve. These weather reports are comical at times but sometimes they get it right. The temp has to drop a lot in a short time and it looks as though its clearing here. I say minimum low of 3
My plants seem to have all pulled through the cold wet weather and are doing really well. I was a little worried about the cold wet weather we have had but this strain seems to be very very hardy and if the fruits are nice ill defiantly be growing them next year as they have had no problem at all with the conditions Im very suprised
Posts
A bit of rain won't hurt the plants. Blight arrives via fungal spores travelling on the breeze. If they're around, they will infect the foliage wet or dry. In other words, covering them from rain won't stop infection.
Italophile I have seen articles from respected professional gardeners that say Late blight is caused by the Phytophthora infestans fungus and affects both tomatoes and potatoes. It is especially dangerous if the weather is particularly cool and wet. Late blight was the fungus that caused the Irish Potato famine. The leaves will have lesions and will appear as irregular gray spots. If the weather is damp a white mold may appear around the spots. Once the tomato fruits become infected they will develop dark regions that will cover a large percentage of the tomato. The fungus may be spread tomato plant to tomato plant by wind or rain.
I just found this on early blight
Early BlightCommon Name: Early blight of tomatoes
Scientific Name: Alternaria solani
Symptoms
One of the most severe tomato diseases affecting home gardeners, early blight can affect the stems, leaves, and fruit of tomato plants. It can also cause damping-off in seedlings. It doesn't occur in arid dry regions but is most active in warm, wet or rainy conditions.
Plant symptoms: Brown circular "bull's eye" rings appear as 1/2-inch diameter leaf spots. The spots appear first on lower, older leaves. As the disease progresses, stems and fruit may become infected. Leaves turn yellow and wither, starting at the base of the plant, until the whole plant is affected.
Fruit symptoms: Similar to the leaf spots, the spots on fruit appear as dark brown concentric rings with the presence of dark, dusty spores. As the disease progresses, the spots on more mature fruit may appear larger, dark, dry, and sunken.
Causes of Early BlightThe fungus survives in infested soil and plant residue. Therefore, planting successive years in the same soil can cause a recurrence of the disease. It is caused by different fungi than late blight. The disease can be carried by infected seed and can be spread by wind, water, insects, humans, and equipment. The spores that land on plants will affect the leaves when they are wet.
The Alternaria fungus is most severe on plants stressed by a heavy load of fruit or low nitrogen fertility and is worse during the rainy season.
Control of Early BlightA combination of practices can help keep the fungus under control. The best method is prevention. Once it's started the disease is very difficult to control. Fungicide may be your only option.
Preventative measures:
Chemical control:
For more information on the Alternaria fungus and other tomato diseases, contact your county Extension office.
That's mostly all true, Christopher, though their advice to spray after you find early symptoms of Early Blight is crook. The only effective spray technique is preventive - before the spores arrive. Once leaves are infected, there's no killing the spores apart from removing infected leaves and destroying them.
Late Blight is a lot, lot less common in domestic gardens. Early Blight is probably the most common domestic fungal problem, along with Septoria Leaf Spot.
My point was only that covering the plants won't protect from infection. Won't even reduce the chances. While damp foliage can be an incubator, the spores will still infect dry foliage. I see it every season. I get zilch rain in summer, have very low humidity, and still end up with Early Blight.
I decided to just put them out today I erected supports made from canes and in total put about 20 plants in the garden. As we have a break in the weather I was thinking now is a good a time as any. I still have 15 plants in reserve and they will replace any casualty's. It took me all day to get it done but its done now I just hope they survive. They are best out where they can get the sunlight and nutrients they need. My Amish paste are not as strong as the Black Russian they seem a weaker plant but they have all germinated and ill slip them in when i think they are strong enough. I may have to give a few plants away as I have room for maybe ten or so more as I don't want to give up too much room but that all depends on how my outdoor ones cope
Widespread ground frost forecast by the Met Office for next weekend
UK Outlook for Saturday 3 May 2014 to Monday 12 May 2014:
"....Most areas fine and dry with sunny spells this weekend, although there is a risk of a few light showers in the east on Saturday whilst some northwestern parts may turn cloudier with patchy rain on Sunday. Cold overnight, with fairly widespread ground frost, but daytime temperatures around average so not feeling too bad in sunshine. The mainly settled conditions look to persist through the early part of next week, temperatures then probably rising a little above average with the risk of overnight frost reducing. Northwestern parts, however, may remain cloudier with a risk of rain at times. Thereafter, most likely a return to slightly more unsettled conditions, particularly for western and northern areas, with near average temperatures and still a risk of colder interludes affecting the north at times...."
Gardening in Central Norfolk on improved gritty moraine over chalk ... free-draining.
Ill have to cover them then I have some polythene coming tomorrow. But I honestly cant see a frost where I am. It was supposed to be a colder and a rainy day today
Hope you're right - I'll keep my fingers crossed for them.
I'll be fleecing my figs and gooseberries at the weekend - my tomatoes are still indoors at night.
Gardening in Central Norfolk on improved gritty moraine over chalk ... free-draining.
Yegh Ill cover them for sure but I cant see a frost but if we do have one I have plants in reserve. These weather reports are comical at times but sometimes they get it right. The temp has to drop a lot in a short time and it looks as though its clearing here. I say minimum low of 3
My plants seem to have all pulled through the cold wet weather and are doing really well. I was a little worried about the cold wet weather we have had but this strain seems to be very very hardy and if the fruits are nice ill defiantly be growing them next year as they have had no problem at all with the conditions Im very suprised