Flower buds swell ,is it too late to spray bordeaux?

Every year I spray my peaches and grapes with bordeaux while they are still in dormant. It works well for me. Now, I have J. plum, cherry, asian pear and Apricot in buds swell stage. I don’t want to mix two batches of bordeaux, if I can avoid doing that. So my question is if I spray plum, cherry, apricot now, will the bordeaux spray cause damage to the flower buds? I plan to mix weak strength of 8:8:100 tonight

This is the J. plum buds:


This is the Asian pear buds:

This is the Apricot buds:

Bordeaux oils are typically surfactants or penetrants. On their own they can surpress relatively mild infections by mechanical interference. Many of us are jealous that it works by itself for you. In locales where it is desirable to apply a mineral by foliar spray during the rainy season, bordeaux oil is often in the mixture to sustain the application.

Looking at your pictures, I would not apply a bordeaux mix at that stage. However, a late afternoon application of Spinosaid or derivative (e.g. Conserve SC) would prevent many larvae including thrips from infecting your fruit.


Just curious why you are spraying bordeaux on apricots and plums at this stage. Are you trying to control blossom blight? Of course disease pressures are different in different locales, but we never have to spray a fungicide on stone fruits during the growing season until after shucks-off. I understand your use of bordeaux for leaf curl on the peaches during dormancy.

That said, I’ve never used bordeaux, but have used copper. Copper could easily be sprayed at tight cluster on your plums, or first white on apricots. Bordeaux is said to be slightly more phytotoxic than copper, but I still wouldn’t be afraid to spray the trees pictured at this stage with bordeaux if you had a reason.

Bordeaux does not have to be mixed with oil, a surfactant, or a penetrant. I’d probably avoid mixing bordeaux with a penetrant. My guess is that it would increase the potential of phytotoxicity.

Unlike Richard, I probably wouldn’t spray an insecticide at this point. Since you are in zone 5, you’ve probably almost never seen a thrip (like me). I understand Richard’s perspective, as thrips can be a real issue in CA, but unless you are seeing them in your area, I wouldn’t be concerned about any insects until after shuck split, or shucks-off.

Oplea, I realized that not many people use Bordeaux, but it is a very effective fungicide and it is cheap and easy to mix. In my area, I don’t have high diseases, pests pressure except squirrels . I just don’t like to have too many bottles of poison in my garage especially some ingredient unknown. Commercial Cooper spray fungicide can be applied up to half green,weak strength of bordeaux should be fine at this stage. Yes, Bordeaux is slightly more phytotoxic compared to commercial copper spray at same concentration, but Bordeaux will last longer on the tree, less affected by weather. In the past, my fruit trees bloom in order, but this year, somehow, everyone decides to wake up and blooms at the same time, at least more closer in time.
I did not see thrips on my trees, I do not mix bordeaux with oil or any others, Just one Bordeaux application is enough for the rest of the season. This statement could change though because something new always show up… Well, this is the fun of growing fruit trees