Do you have stone fruit trees, such as peaches, nectarines or apricots? If so, give them some TLC now with Bordeaux spray to minimize leaf curl and other fungal diseases this summer.
Leaf curl is a fungus that loves cold and wet conditions and infects peach, almond, apricot and nectarine trees. As the tree buds swell the fungus gets to work infecting the leaf cells. This stimulates the leaves to grow larger than normal and often with a reddish tinge.
The good news is, that leaf curl is easily preventable with one or two well-timed applications of a fungicide spray such as copper sulphate or Bordeaux spray. Spray the trees in winter while they are still dormant and just as the buds begin to swell. Consider a follow-up spray again when the flowers open. You need to spray enough to cover all the bare branches of the tree so that it’s dripping
There are many commercially available fungicide sprays available at your local nursery or hardware store. If you’d like to have a go at making your own, try this recipe for Bordeaux spray
How to make Bordeaux spray
1. Mix lime and water
Dissolve 100 gram of builders’ (hydrated) lime in half a standard (plastic) bucket of water. (About 5 litres). Do not use metal buckets as the mix reacts with metal. Stir well with a wooden or plastic spoon.
2. Mix copper sulfate and water
Dissolve 100 grams copper sulphate in a separate half bucket of water. Keep stirring the lime mixture to prevent it settling and pour it steadily into the half bucket of dissolved copper sulphate..
Pour the mix into a sprayer. Add enough extra water to make up a total of 10 litres of the finished Bordeaux mixture. Wet all plant surfaces thoroughly, especially bark fissures. Bordeaux spray (and lime sulfur) settles, so shake the sprayer every now and then. It is at its most effective strength when freshly mixed so used immediately or within a couple of days. Using it straight away also means it’s less likely to clog spray nozzles etc.
Wash off any spray that splashes onto turf, or other foliage, using fresh water. Thoroughly clean out sprayers with warm soapy water, paying particular attention to nozzles.
Bordeaux spray and lime sulfur burn leaves, which is why they must be applied during winter dormancy before flower buds or leaves open.
Copper based sprays have a blue tinge, and may stain so it’s a good idea to wear old clothes, safety glasses and gloves while spraying.