Our little nectarine tree had gorgeous blossoms this spring. Unfortunately, they were accompanied by some rather unsighlty twisted and red blotched leaves. We did some research and concluded that it has fallen prey to peach leaf curl. Peach leaf curl is a fungal disease of peaches, almonds, nectarines and occasionally apricots, which causes distorted leaves, also making them fall prematurely. Being a fungus, spores grow on the affected leaves, and the dust released by the spores then winters over on the tree (all over the tree) and on the ground around the tree. The fungus is activated and spread in the spring by the right combination of excess water (rain or irrigation) and cool to warm temperatures. Sounds nasty 😦
So we did more research and these are the natural treatments we’ve found that we are going to try:
Removing leaves: Not really a treatment, more of a control method. We’ve read a lot of opinions about whether removing affected leaves has any benefit. Our opinion is yes. When the leaves come out red or with red blisters on them – remove them. By the time these leaves are going whitish the spores have developed. Sure, removing leaves probably won’t do much to treat the fungus this year, but it should lessen any outbreak next year. Most of the affected leaves will fall anyway, but those damaged leaves should also be collected and disposed of. If not, they will store spores till the following season, increasing the infection from one year to the next.
Oregano Oil: Any fungicidal treatment should idealy be started before the buds swell to protect the newly developing leaves from infection. Dilute 6-7 ml of oregano oil in a 16 0z bottle of water then spray the tree from trunk to the top as well as each branch. Do this a couple times this year and be sure to start early the next year. Trees should be sprayed to the point of runoff or until they are dripping as spores can hide underneath the bark, around buds, and in other protected areas.
Feed: Because infected leaves drop and need to be replaced with healthy leaves, it’s really important to give your tree all the nutrition it needs to help it do this.
- Compost tea can be sprayed, and if there’s any left over, it can also be used as a soil drench.
- Spent coffee grounds can be used as a mulch around the base of the tree for added nitrogen.
- Epsom salt can be added to the soil around the base of the sick plant for extra magnesium, or, for faster absorption you can mix 2 tablespoons of Epsom salt in a gallon of water and spray it directly on the leaves. (As a side note, leaf curling can also be caused by a simple magnesium deficiency so this is a good practice to keep regardless of whether the tree has peach leaf curl)
Shelter: Where peaches are grown trained against a fence or wall, a rain shelter of plastic sheeting can be very effective at preventing the spread of infection. It should cover the top of the tree and the front to within 30cm (1ft) of the ground, but with the ends open to allow access for pollinating insects. It should be erected after leaf fall in November and kept in place until mid-May. Keeping the emerging shoots dry in this way helps prevent infection and also gives useful frost protection.
Repetition: Treatments should be repeated a few times a year; a dry spring can mean you won’t get the symptoms that year, but the infection can still come out the following year if the right conditions occur.
Yearly Peach Leaf Curl Treatment Guide
Here is our general guide for treatment throughout the year:
- As soon as you notice leaf curl, remove the infected leaves or let them fall but then promptly remove the fallen leaves. Remove them from your garden entirely – do not add them to the compost heap.
- Come early summer when it is getting hot, and the spring rains have passed, apply loads of fertilizer, especially one high in Nitrogen and supplement with Epsom salts. Supply adequate irrigation. The idea here is to help your tree recover vigorously in order to replace the infected leaves which will fall off. The new vigorous leaves will not be infected in the drier months, and it will help your tree prepare much better for next year.
- Around fall, remove all fallen leaves before they decay.
- Apply your first batch of oregano oil around November. Also spray the fences and the soil and nearby trees where possible splashes from the rain could reach. This is also the time to build a shelter if desired.
- Around Christmas, be sure to remove any leaves still hanging on the trees. Then spray again with oregano oil.
- In early spring, before the buds are starting to swell, apply the oregano oil again.
- Around may, once the weather is hotter and drier, remove the shelter.
If you know of any other natural treatments, do let us know. Fingers crossed these work!