There is a common problem with fruit trees in temperate climates where the trees flower before the last frost. Generally speaking, if the tree has flowered, and the temperature drops below freezing, the flowers die and do not produce fruit.
This is certainly not a new problem. It's my understanding that the problem affects almost the entire fruit farming industry in temperate climates.
I've heard that fruit farmers have large-scale commercial techniques that they use to mitigate the issue, such as:
- Fog or smoke
- Wind Machines
While these methods might be practical for commercial farmers, not all of them are practical for small-scale urban farmers like me.
One technique that us gardeners often wonder about is:
Instead of actively protecting the open flowers, would it be possible to trick fruit trees into not flowering as early? In other words, keep the ground frozen longer than it would be naturally, to delay flowering (I'm making an assumption that trees don't flower when the ground is frozen).
While such a technique would likely be impractical for large-scale farmers, it might be resonably practical for small-scale gardeners.
Note: I imagine that there are more factors at play than just ground temperature. For example, the amount of sun, angle of the sun, and the temperature of the air might also be factors when it comes to the flowering timing.
I suspect that prolonged frozen ground conditions could significantly delay the tree from flowering (maybe by a couple of weeks) which would make a huge difference when it comes to avoiding late frosts from killing flowers.
Can I prolong frozen ground conditions to trick fruit trees into flowering later?
An idea would be to insulate the ground around the tree with snow. The theory being that the insulation would prevent heat from the sun from warming up the ground where the roots are.
However, an obvious problem with snow is that it melts, and not always when you want it to. From past experience, I'm guessing that this pile of snow will mostly melt before it is helpful to me (before late spring).
I'm dealing specifically with plants in the prunus genus:
- Prunus tomentosa
- Prunus besseyi x prunus salicina hybrids
- Prunus avium x prunus salicina hybrids