Creating a humid atmosphere in your greenhouse

[Emily Peagram]

Hi everyone!

Seeing as temperatures are set to soar this week, we'd like to know how you all maintain a humid atmosphere in your greenhouse to keep certain crops happy. Do you damp down pathways? If so, how often? Any other methods you think are useful would also be appreciated!

Please note that answers may be edited and used in the September issue of Grow Your Own magazine.

Thanks

Emily

[maverick451]

I have a question on this

Isnt that just asking for blight?

[Emily Peagram]

Hi Maverick,

Too much humidity can cause conditions such as blight to develop. However, creating the optimum levels can help to protect crops from heat damage It's a subject that can be difficult to strike a balance with, which is why we're interested to know what works for everyone.

[bario1]

Which crops prefer humidity? I'm guessing cucumbers?

[Guest]

I just give everything a good drink in the evening and that seems to be fine if I get the path as well so be it. Although I could probably do with watering down the path in the morning of one greenhouse as it dries out a lot.

Edit: higher humidity is also meant to help reduce red mite and other beasties.

[Martin H]

I don't do anything special. The greenhouse is very full at this time of year and it always feels quite humid after I've finished the morning watering. Also my watering cans leak a bit so there will be a damp patch on the greenhouse floor for most of the day.

[Thelma Sanders]

I make sure the greenhouse end border, where the cucumbers are, have had a really good soaking.....
seems to work ok.

[marchogaeth]

I do everything I can to keep my tunnel dry - blight is my biggest single worry. I water below the surface using sunk drinks bottles. My cucumbers are under the tomatoes so will have less air movement around them. I differentially spray their leaves if needed. Aubergines get planted in the middle of the tunnel and can also get a spray if they look like they need it.


Edit:- it hit 50C this week (well 49.6) even with the doors on both ends wide open. Only the cats were still begging for more. The tomato leaves were just too curly and even a little crispy. In the absence of any blight warnings (jinx) I watered some of the soil and sprayed a bit around in the air over night.

[rhonsal]

I work away quite a lot so try and multi task - all my greenhouse plants are in pots (due to poor soil in garden to begin with) so keep trays under them, which helps with watering and humidity.

I've also rigged up some extra irrigation for the thirstier plants using watering bags and drip feed lines - fingers crossed!

[Potstubsdustbins]

I have an 8 x 6 greenhouse with a full concrete floor (no beds). This can be an advantage early in the year as the concrete acts as an overnight heat store on sunny days. However come the hottest days of summer it can be to much for some plants particularly cucumbers.

I therefore monitor humidity along with temperature to try and achieve a balance, sometimes not easy with tomato's and cucumbers in the same greenhouse. I find what works for me is to empty a watering can over the floor on my last visit of the evening, this soaks into the concrete and then evaporates throughout the next day keeping the humidity at a reasonable level. You do have to have decent ventilation as well though.

[Potstubsdustbins]

As a bit of a guide I monitored humidity in the greenhouse and the house today.

Last night anticipating a hot day today I wet down the greenhouse floor at 9-00pm. At 8-00pm this morning humidity in the greenhouse was 59% by 4-00pm this afternoon it was down to 31% a very dry reading.

Humidity in the house hovered between 41% and 43% all day.

[Jay-ell]

I have a blowaway greenhouse tent which has no ventilation so I hose down the floor which soaks through the weed fabric and into the ground. Steamy as anything today but the melons are romping away the last couple of days.


The little see through shack greenhouse has better ventilation (mainly due to the fact that nothing is square and there's gaps everywhere) so I have my pots in trays to water and keep the place humid.

[bramble]

My greenhouse has a paved floor. Inthd hot weather iempty abucket of water on it at about midday and it seems to work. My father made a living from working in commercial greenhouses and he always advised me to do this.