Hello peaches…

Anzac peaches need thinning
Anzac peaches need thinning

The Anzac peaches (one of the first to flower at our place) have set a good crop as usual, and it’s time to start thinning.

This is a good time of year to start assessing the impact of a couple of common diseases that can play havoc with our fruit trees, often without our realising it. 

You’ll also be thinning your apricots soon (if you haven’t already started), so while you’re doing so, it’s a good time to be looking our for signs of blossom blight in your tree.

Castlebrite apricot tree with blossom blight
Castlebrite apricot tree with blossom blight

Even though this disease does most damage when the tree is flowering, it can also affect the fruit that has set – because the disease that causes blossom blight also causes brown rot.

It’s not unusual to see remnants of it alongside healthy apricots, if you’ve had a mild case.

Flowers infected with blossom blight
Flowers infected with blossom blight

If you notice any of these diseased flowers on your apricot tree and you also have healthy fruit, it’s a good idea to knock or prune any diseased flowers and shoots off, for two reasons.

The first is that they can contribute to disease outbreaks next year, but the more urgent reason is that the pathogen that causes blossom blight also causes brown rot later in the season, and developing fruit is very vulnerable, as you can see in the following photo:

Photo showing Brown rot infection of a young apricot (blue arrow) that started from a flower that died due to Blossom blight infection (red arrow)
Photo showing Brown rot infection of a young apricot (blue arrow) that started from a flower that died due to Blossom blight infection (red arrow)

The other disease to check for is leaf curl, which is usually fairly obvious, the red leaves are a dead giveaway.

Leaf curl on a peach tree
Leaf curl on a peach tree

Only peaches and nectarines are affected by this tree, and if you’ve had a really bad case, it can also affect the fruit, so this is another thing to be looking out for while you’re thinning because you may as well pull the infected fruit off.

Affected fruit looks like this:

Leaf curl infection on a Goldmine nectarine
Leaf curl infection on a Goldmine nectarine

It’s not uncommon to end up with one of these infections despite having sprayed, which is super annoying.

There’s a couple of potential reasons for this. The first is that you may not have the right spray equipment for the size of the job you need to do – you can review the various options in this short course (because if you’ve gone to the trouble and effort of spraying, it would be really good to make sure it’s going to work!)

The second reason is that you may not have got the timing quite right, and the right conditions were in place for the fungal disease to take hold in the tree unimpeded.

Of course the long term aim is to get our orchard and trees healthy enough so they don’t need spraying, but while we’re building this biodiverse paradise, a bit of crop protection can go a long way!

Earwigs – love them or hate them?

This week we’re talking about earwigs – should we hate them, or love them?

A nest of earwigs in a crack in a fruit tree
A nest of earwigs in a crack in a fruit tree

There’s nothing like finding a writhing nest of earwigs in a crack in a peach tree when you’re pruning (watch the video here) to reminder you that it’s time to take some steps to prevent these apparently insignificant creatures from wreaking havoc in your stone fruit trees.

What other insects are in this category? The other main one that causes an issue for a lot of stone fruit growers is garden weevils, but there are lots of insects that can walk into your fruit tree and make a mess, such as harlequin bugs and many different types of weevils.

As we’ve mentioned in other blogs, the key to effective pest and disease management is to figure out how to protect your trees (or fruit, depending on the pest) from the pest, rather than trying to get rid of the pest (which is expensive, ineffective and may even be damaging to your ecosystem).

So, how to prevent them?

Using sticky tape for earwig control in a nectarine tree
Using sticky tape for earwig control in a nectarine tree

Using our first principles of pest control, first look at their life cycle. These pests overwinter in cracks in the bark in your tree, or in the soil or litter under the tree.

They also love fence lines, bits of wood, or in fact anything lying around on the ground that provides them with darkness and shelter.

In late winter/early spring, young hatch and they start moving and will often head up into your fruit trees as soon as there are buds or fresh new leaves to munch on, even before there’s any evidence of fruit.

The key to controlling them is understanding when they’re likely to be moving (Answer: in late winter/early spring), how they get where they’re going (Answer: they walk up the trunk) and what they do when they get there (Answer: hide in a dark place during the day and come out at night to eat your fruit! Some individuals may leave the tree to return to a nest elsewhere, but they may also just take up residence and stay in the tree, making it hard to get rid off them once they’re there.).

This is the approach we use with all our organic pest control, and the basis of our short course Protect Fruit Trees from Pesky Pests which not only covers earwigs, but also bugs, weevils and all the other common pests.

Once you know all that, figuring out how to prevent them becomes relatively easy – you just have to provide a barrier they can’t walk over, and you have to do it earlier rather than later.

On the farm we do this with double-sided barrier tape, but you can achieve the same result with anything sticky – horticultural glue, or even a layer of grease (but put a physical barrier such as plastic wrap around the trunk of your tree first so you don’t hurt the tree).

If you haven’t experienced earwig damage in your fruit before, here’s just one example (below) of what they can do.

Earwigs that have taken up residence inside a peach
Earwigs that have taken up residence inside a peach

If numbers build up enough, they can be as devastating to your crop as birds, and really need to be taken seriously. Having said that, as trees get older and larger and bear bigger crops, you may lose a smaller proportion of fruit and the damage is often confined to the lower branches, but it’s still a pest worth preventing.

An earwig inside an apricot
An earwig inside an apricot

So, having decided that earwigs and garden weevils are most definitely a pest, why ask the question about whether to love them or hate them? Surely we just hate them, right?

It’s never that simple! Turns out that earwigs are also a wonderful predator of aphids (particularly the very messy white Woolly Aphids that can appear in your apple trees), which is a great example of why it’s never a good idea to kill insects – just encourage them to hang out where they can do the most good and the least damage in your garden!

How to Prevent Leaf Curl

Leaf curl is a nasty fungal disease that affects peaches and nectarines, but it’s often confused for other things (well, other things are sometimes mis-labelled as Leaf curl).

Here’s what it looks like:

A peach tree with the classic red leaves of Leaf curl disease
A peach tree with the classic red leaves of Leaf curl disease

There are other things (both pests and diseases) that can make leaves curl in other types of fruit trees, but this particular pathogen only affects your peach and nectarine trees.

If you get a bad case, it can even affect the fruit, and really bad cases will make the fruit fail and fall off while it’s very small, before it gets a chance to grow. Notice how similar it looks to the disease on the leaves, with a rough, raised texture and the red colouring.

A nectarine infected by curly le
A nectarine infected by curly leaf

Why are we showing you what Leaf curl looks like in the middle of winter? Because if you saw any signs of this disease last year, now is the time to be treating your trees to prevent it happening again this year.

It might seem too early to be thinking about spring, but if you wait until you see the disease, it’s way too late to put out the preventive sprays.

A Goldmine nectarine bud swelling
A Goldmine nectarine bud swelling

The trigger to spray is bud-swell. Different varieties reach bud-swell at different times, which is where the skill comes in. Depending on where you live and which varieties you have, your trees may already have reached (or be past) bud-swell, but if your peach and nectarine trees still look completely dormant, that’s because they are. From now on you need to be monitoring each different variety so you can spray them at the right time.

Once you’re sure your tree has reached bud-swell, it’s time to apply a preventive copper spray – Bordeaux (which is made by diluting hydrated lime in water, and copper sulphate in water, then mixing them together), or a spray containing copper hydroxide are the best options for home use. The Better Fruit With Wise Organic Spraying short course includes a video demo of how to mix Bordeaux spray if you need more detail.