Checked the Twin Span. Winter is a tricky time of year, it's really easy to overwater and hard to know just how much to water. All sorts of factors to consider, appearance of plants and soil, if the pot is heavy or not, whether there's moisture beneath the pot on the mypex, taking the plant out of the pot and see how well watered through they are. Blanket water or to spot water. Trying to treat one type of plant generally the same helps efficiency, but is then sloshing the way forward when only a small handful of plants within a group is dry, how effective is it all in the long-term, better to lose a small certain amount of plants then fuss too much?
The Salvia has powdery mildew - some of the fancy patterned ones seem to suffer more, Salvia officinalis 'Purpurascens' seem most worse for wear and the tricolor ones. I'm generally keeping Lamiaceae plants on the dry side, but powdery mildew is bad when a plant is watered inconsistently - left too dry and then suddenly really wet. Ventilation helps. Sam mentioned that to reduce rust and mildews we are going to look at taking a thin layer of soil off the pots, to try and reduce any spores sitting on top of it and to pick over plants more. Weather wise it is sunny a lot at the moment though still cold, it can suddenly heat up very quick in tunnels and under glass - so houses tend to need ventilating and a over all check twice a day is required, in case there are sudden loss of water from some plants.
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| Photo 1: Rolling up the plastic at the back of the Twin Span tunnel. The sides can be rolled up too. |
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| Photo 2: Potting up irises. |
There was a Prop. team meeting today - they're looking into obtaining LED lights for future set-up. They are good, but as the old lamps that were used radiated so much heat, if a house is old and rickety and not well insulated, nursery growers found that their heating bill went up substantially when using LED.
Doug went to AHDB conference and related back useful info -
- In 2009 it was made legal that commercial growers like institutions had to use IPM (e.g. monitoring, using pest control first) and would do what they could before they resorted to chemicals.
- Things like Aphox and Decis - aphids are now immune to (this is probably a result of continual use of chemical instead of more diverse control). There are FRAC Codes to help guide what chemicals can't be used together or one after another.
- Nimrod, Bumper, Systhane are used for early colonisation of powdery mildew
- Sodium bicarbonate is suppose to be effective against liverworts
- Rust if present on plants appears will appear after a month in quarantine.
- Serenade a bio-fungicide is also used to water in plants.