Blight and undercover spuds/toms

[veggiechicken]

Probably a daft question but..............you wouldn't expect anything else from me

If blight is carried in the air and rain, if I grew spuds in bags or GH borders would they still get blight.
And...............why do toms in GHs get blight?

[sparrow100]

Because you open your greenhouse window to ventilate and the door to get in....?

You might have a reduced risk, but it's still there.

[Kristen]

I think risk is significantly reduced for Tomatoes in greenhouse, particularly if you water at the base and don't wet the foliage, as the blight spores need moisture on the foliage to "germinate"

I imagine the same is true for spuds.

But with hot & wet conditions in a lousy British summer (i.e. that lead to Smiths Periods) the humidity etc. will probably still be enough to allow the blight to attach the greenhouse plants.

Only growing 1st early spuds helps, as they are harvested and out of the ground before blight strikes (apart from early blight, but that's something different and nothing like as infectious for the plants)

Given that main crop spuds are cheap (yeah "as chips" ) to buy then just growing Earlies is one answer (if you are not fussy about variety, and trust the provenance of the ones you are buying of course)

[pigletwillie]

I used to have two 20 x 12 poly tunnels on one plot. I have had tomato blight twice in those tunnels so yes you can. Also with it being an almost confined (and humid after watering) environment it will spread very very quickly.

[Penellype]

I find growing potatoes in bags helps a great deal. If you notice blight on the leaves, fold the bag in as much as possible so that the spores can't fall onto the soil. Not foolproof, but better than bare soil.

[marchogaeth]

I read somewhere that you should put the tomato plant in new soil/compost but it doesn't matter if the roots go down into soil that has had tomatoes in previously (breaks between crops are best but I only have two beds I can use for tomatoes and only one for climbers) so I use "The flower buckets" as in the picture below with new soil/compost in. I water the plants in for a few days until they are established. After that I only water through the double bottle system - also in the picture. The bottom bottle has no lid in it and the top one either has a small hole punched in it or the lid is slackened off so it leaks a bit.



This really reduces the humidity in the tunnel. I do nearly all my watering in there on variations of this theme. I also have a set of doors that face away from the prevailing wind so I can open those on most days so that air can circulate. If it gets too dry and spider mite appears, I mist (and sometimes soak the beds around) the affected plants until they clear off and again.

I do completely soak the beds a few times a year and some crops just get the watering can or hose especially over winter.

I only grow earlies in the tunnel, if at all and always in bags but I guess you could apply this system to grow bags on top of soil. Water the bags until the plants are established and then water "under" the bags using the bottles either buried in the bags or the bed.

Finally, when I feed I do so at the top using a liquid - the idea being it's the tomato/cucumber etc that gets the feed and over a period of time without it being washed away by watering.

PS These are Chadwick Cherries from seed a friend brought back from the US. Will be seed saving and sharing later in the season, I hope, should they prove to be tasty.