Over the Fence
A selection of horticultural hints and Tips

Seeds

    When sowing seeds, as a rule of thumb bury them the depth of their own diameter. Mix fine seeds with sand for easier sowing to ensure they are spread evenly over the compost surface.

    Always sow seeds in new seed compost, don't try to make do with ordinary potting compost even if it says it's ok on the bag. Trials show that seeds germinate best in seed compost (surprise!) and trying to cut the cost by using what you've got will almost always turn out to be a shot in the foot when some seeds germinate poorly or not at all.

Pests and disease

    Elder spray.  This kills aphids, small caterpillars and is useful as a fungicide for mildew and blackspot on roses. The toxic agent is hydro-cyanic acid, so in preparing the spray use an old saucepan.

Gather 450g (1 lb) leaves and young stems of elder prefer-ably in spring when the sap is rising. Place in the saucepan and add 3.3 litres (6pt) water. Boil for half an hour, topping up as necessary. Strain through old tights and use the liquid cold and undiluted. It will keep for three months if bottled tightly while still hot.

    Slugs and Snails (again - the problem lasts forever.....)  Another possible way of keeping slugs away from sensitive plants sprinkle eggshells around them. Ash and grit are also supposed to be effective. Sprinkle slugs with salt to kill them (if you can stand the resulting agony). It is also possible to trap slugs using containers in the ground that have some beer in the bottom, though you still have to get rid of them which is a problem if you don't hate your neighbor.

Empty grapefruit halves work as well. Petroleum jelly smeared around plant pots stops slugs getting to the plants inside. Personally I have to admit to being a fan of slug pellets. They're very effective, ideal for the coward (like me) as you don't see the dead or dying slug/snail and not much effort. Go for the smallest pellets and ignore claims of "rainproof" - it usually just means "bigger and so take (marginally) longer to disintegrate". Scatter them evenly so they land a couple of inches apart, mounds don't work - the molluscs can't see them and don't know that they're supposed to go there to eat them.

Another way to deal with your captured slugs and snails (though I haven't tried it myself) is to put them in a plastic Tupperware type container and then put them in the freezer. This is probably the most humane way as they just slow down and become torpid in the cold being cold blooded (yes they do have blood of sorts). So they are effectively anaesthetised before being frozen.

    Nettle spray.  The common stinging nettle is a discerning plant that requires high levels of nitrogen in the soil to grow well, using the leaves in sprays of several kinds. As well as using nettles as an activator on the compost heap the organic gardener can use them as a liquid manure and as an aphicide - to kill aphids (greenfly).

Gather 224g (l/21b) young nettles and soak in a bucket of water for a week. Strain and use undiluted as a control of aphids on roses and celery leaf miner. Add the mushy nettles to the compost heap.

    Rhubarb spray.  The oxalic acid in rhubarb leaves is a safe control agent for aphids, particularly those on roses. Cut 450g (1lb) rhubarb leaves, place in an old saucepan (the oxalic acid may damage one that you still use) with 1.1 litres (2pt) water and boil for half an hour, topping up as necessary. When cool, add 1 dessertspoon of soap flakes dissolved in 275ml (1/2pt) warm water. This acts as the wetting agent when added to the strained rhubarb liquid. Stir the mixture thoroughly and use undiluted as a spray.

    Avoiding whitefly on tomatoes without the use of chemicals.  Plant French Marigolds (Tagetes) between your tomato plants to keep those pesky Whitefly away. It's not that the Whitefly particularly don't like these marigolds, it's because the pungent smell from the marigolds masks the nice smell of the tomatoes that usually attract the Whitefly.