I’m often asked the same questions by different people so I thought it useful to publish some of the emails I get and the answers for everyone.
Mildew On Plants in Coldframe
“I have a wooden cold frame for the first time and during last winter, lost some plants due to mildew/condensation. Apart from heating it, is there anything I can do to get ready for this winter?”
Condensation is a problem with greenhouses and coldframes in the winter since it creates the ideal conditions for fungal diseases. There’s only one real answer; ventilation. Heating can result in a hot damp atmosphere, which is even worse for encouraging disease.
The thing to do is to open up the frame or house whenever the weather allows in the morning, closing back up as night falls. In cold weather, just open a crack but on a fine sunny day, open up as much as you can.
Lola asks (edited):
“I’ve suffered an infestation of earwigs and they have certainly had a feast this summer. How can I stop them ruining the next summer of plants?”
Earwigs are rarely a major problem in the garden and because they’re omnivores are quite beneficial as well eating some of the pest insects in the garden. However, they are partial to some young flowers and can be a problem with sweetcorn as well.
There are chemical controls (check in your local garden centre), but please don’t jump for the spray unless you have to. If you stuff some plantpots with hay or shredded paper and place these in and around the plants, the earwigs will hide in there for the day.
Just take the pot to the other side of the plot or the chicken run and shake out in the morning. This should keep the numbers and damage down leaving enough around to do some good for you with the pests.
Alternatives to Lime to Decrease Acidity (raise pH)
“I am now living in Spain and have been here for 5 tears now. I have a terrace where I grow tomatoes and peppers nearly all year round plus salad crops and climbing French beans successfully.
My problem out here is getting hold of good soil as I use potting medium for my boxes and planters. After one crop the nutrients in the soil are usually well used up. I can get hold of manure here plus I make my own compost, but I cannot find lime for the spring cabbages I grow.
The soil I have is filled with my own compost and sea grass is available from the beach. Are there another alternatives to lime as there doesn’t seem to be any available here.”
Wood ash, as well as being high in potash, will have the effect of reducing acidity as would crushed oyster shells (or any sea shell) or calcified seaweed but practically there’s no real substitute for lime. I’m sure it must be available in Spain, perhaps from an agricultural supplier if not a garden centre. Why not contact Spanish gardener and author Richard Handscombe via his website: Gardening in Spain who I’m sure will be able to help.