My parents live in Ventura, CA, and every year they have the Santa Ana winds blow through their area. These winds can easily reach 40 mph. The problem is, they have a lot of trees in their garden, and in particular—citrus trees. So, I did some research to see if their citrus trees are in harm’s way and if there’s anything we can do about the wind. Here’s what I found.
Strong winds with speeds of about 40 miles per hour or more can do major damage to citrus trees by damaging fruits, branches, leaves, and even uprooting the entire tree. However, gentle winds, anywhere from 8 to 12 miles per hour, are actually beneficial to citrus trees, as they promote healthy trunk growth.
The wind is important to tree growth, and it’s an unavoidable part of nature. If you want to grow your trees outside where they have access to fresh air and water, then the wind will also be a part of the equation. However, we’ll look at some ways to protect trees from wind. For now, let’s talk about why wind can be a problem for citrus trees.
What Happens to Citrus Trees with Too Much Wind?
We’ve all seen trees blowing in the wind. Trees were meant to move a bit, and it can be hard to judge what is a dangerous amount of movement by just using your eyes. How can you tell if your tree is getting too much wind? The best way is not to observe how much your tree is moving, but to look for some of the after-effects of the wind.
A clear sign that there has been a damaging amount of wind to citrus trees is if you see a bent tree or broken branches. Breaking often occurs with the heaviest branches, and the added weight of fruit may mean that you lose some of your citrus trees.
Wind stress can reduce your tree’s fruit yield, resulting in little to no fruit on the side of the tree facing the wind. Trees will also start losing leaves, so this could be a sign that stronger winds are on the way and motivate you to take action to save your trees.
Besides parts of the tree littering the ground, there are more subtle signs that damaging winds are taking place. If you notice wilted leaves or brown edges to the leaves, this can be a sign that the tree is not getting enough water. Even if you are giving your tree the same amount of water as normal, a consistent wind will dry it out. This is even more true in winter.
Finally, checking the fruit itself can tell you if the tree is being damaged by the wind. Wind stress can leave scarring on the fruit’s surface. When the fruit is young, this scarring can be caused by leaves blowing by, and later in the fruit’s development, it is caused by branches and twigs.
While the scarring itself is not a problem for the fruit, damage done to the fruit by twigs and branches can introduce bacteria that causes more problems.
Exactly how fast do winds have to be to produce damage like this, though?
What Wind Speed Is Bad for Citrus Trees?
Strong winds are bad for citrus trees, starting at 39 miles per hour. At this speed, winds can damage fruit and snap branches. Winds in the storm range, anywhere from 55 to 63 miles per hour, can uproot trees entirely. Cold temperatures can make winds slower than these dangerous to citrus trees, as they carry a chill.
This Beaufort Wind Chart is used by weather.gov to measure wind speeds and explain their effects to the public. This chart shows that at wind speeds of 39-46 miles per hour, twigs will break from trees. This is the first real wind that might be considered dangerous to growing fruits.
Before this point, leaves might fall, but twigs scratching the fruit and introducing bacteria or even knocking the fruit off is more concerning. The next step where we see trees mentioned in this scale is the 55-63 miles per hour range. In this step, trees could be uprooted. Obviously, this would be disastrous for any tree.
Extreme cold can affect how much damage winds do at lower speeds due to wind chill. Even gentle winds with a speed of about 10 miles per hour can be dangerous for a tree at lower temperatures. Fruit trees are pretty dependent on temperature, so a low wind chill brought in by a strong breeze can have negative effects, even if the wind speed itself isn’t damaging.
Knowing the speeds at which wind becomes damaging is important, but it’s even more important to know how to save your citrus trees from inevitable winds.
5 Ways to Protect Citrus Trees From Wind
Growing citrus trees is a long process (sometimes taking up to 15 years), and it can be heartbreaking to lose your crop to one massive windstorm. To save your precious trees, here are some ways to protect against strong winds, in no particular order:
1. Use a Covering
Strong winds are threatening to all sorts of trees, but they are especially threatening to delicate blossoms. Putting a covering over the tree when a windstorm is approaching can save your blossoms from gusts and debris so they live to produce fruit. Just make sure you take the covering off after the strong winds blow through so that your tree gets the sunlight and fresh air it needs.
2. Plant Your Trees near Windbreaks
A windbreak is exactly what it sounds like: an obstruction that will break, or block the wind. Some common objects that would make for excellent windbreaks include buildings, walls, or even other trees. It doesn’t have to block all the wind as long as it protects against the wind’s full force.
If you need to make your own windbreak, you can use two poles and string up a fabric between them. Like the covering, this is something you would likely only want to keep up when you know a windstorm is coming so that you don’t block your trees from sunlight for prolonged periods. If you create your own windscreen, you could also reposition it if the wind is coming from a different direction.
If you have potted citrus trees you can simply take them inside to protect them from the elements. Place them back outside when the storm subsides so they can benefit from the sunlight and breezes again.
3. Plant Trees Following the Wind
This is similar to the concept of windbreaks, but it is more permanent than creating your own, and possibly more practical if you have a large area to cover. The first tree will act as a windbreak for the rest in line with it, and each tree that comes after will be progressively more protected. This solution might not work as well if you live in an area that is prone to multi-directional winds.
Additionally, staking your citrus trees will help keep them sturdy. Similar to the above, a good way to do this is to stake your first citrus trees which then provide a windbreak for the following trees.
4. Keep the Soil Moisture High
Make sure the soil moisture is high. As mentioned earlier, winds can dry out citrus trees, so it’s critical to remember to replenish that moisture. A dry tree can become brittle, whereas moisture improves the sturdiness of the citrus tree and its roots.
Some good ways to retain the tree’s soil moisture are to increase the richness of the soil and provide mulch. For every 1% increase in the soil’s richness, the soil can retain 20,000 more gallons of water per acre.
If you’re mulching, you can simply provide 1-2 inches on top of your citrus tree’s soil. Some good mulches are leaves, pine needles, and straw. However, keep in mind that pine needles have an acidic pH, so you might need to check the soil’s pH to ensure it’s not overpowering the citrus tree. Try to stay in the 6.0-7.0 pH range that citrus trees prefer.
5. Keep Your Trees Pruned
Well-pruned trees have less surface area than unruly trees, which means the wind catches it less. Because of this, they’re less likely to have branches break in strong winds. Heavier branches are also more likely to break, so taking some of the weight off the end may save the branch.
It’s also important to prune away dead branches because those will break early on, and they can break at points that further damage the tree or scratch the fruit.
There are three areas to consider pruning to reduce chances of being affected by strong winds: the canopy, lower branches, and upright branches.
To see how to prune citrus trees in action, check out this video by LSU AgCenter: