My Trees are Naked! Now What?
It is finally feeling like winter in San Diego and your trees have lost their leaves, so what do we do now? Winter is fleeting in our little corner of Earth, but we do get cold enough to send our trees into dormancy and there are some things that need to be done before bud break in the spring. Here I will give you a quick guide on what needs to be done to keep your trees growing healthy and producing loads of fruit for you and your family.
Giving Your Trees a Haircut
Pruning your deciduous trees is very important for your tree to produce a decent crop in the spring. Pruning and shaping your trees each winter will help keep your trees happy and healthy. There are a couple of things to note about tree biology that will help you understand why we prune during dormancy.
Trees store energy in their roots throughout the warm months. This energy is used in the spring to flush flowers and new leaves. Since the tree hasn’t produced leaves yet, and therefore cannot photosynthesize, it relies on this energy to get things started in the spring until photosynthesis can take over. As a general rule (though there are exceptions) most trees only produce fruit on yearling wood, or wood that has grown the same year as the fruit. Older wood will produce new branches, which will produce fruit.
By pruning back our trees we allow them to use their stored energy more effectively. Instead of all that hard earned stored energy in the roots going to keep a large quantity of live wood alive, the tree can put that energy into growing more new wood, which will end up in more fruit. Secondly. The more wood you leave on the tree, the less energy your tree has to allocate to producing fruit. This results in smaller fruit, less sugar development, and fruit dropping before it is fully ripe.
It is important to note that if you are pruning your trees for the first time it can be a bit daunting. Oftentimes, you are going to want to “hard prune” your trees, meaning you are removing up to seventy five percent of your tree. I will always advise you to get an in-person lesson before taking a saw to your trees. One hour spent learning some basic techniques from a professional will not only help ease your anxiety but will also help to prevent future problems caused by poor pruning. You can always reach out to us for tree pruning lessons.
Battling the Bugs and Fungus
This can be a real issue. I have been known to condemn many trees due to bug infestations and fungal issues and it always makes me sad because it is quite avoidable with some basic winter care. Along with pruning, dormant spray applications are very important. Three applications each of both horticultural oil and copper fungicide are the minimum recommended preventative treatments. I will try to get four to five applications, if I can. Our short winter season can make that difficult if you get a late start, however.
Copper fungicide is used to control and prevent a variety of fungal issues and we won’t discuss them all here. In San Diego we are using copper fungicide to prevent/control primarily leaf curl fungus. Leaf curl fungus will cause blistering, bubbling and discoloring of the leaves and will cause them to fall. As we all know from elementary biology, if a tree loses its leaves it cannot grow or produce fruit. Leaf curl is extremely difficult to stop once you see it on the leaves and will result in a failed crop, so avoiding it altogether is your best bet.
Horticultural oil is your remedy for most of the bug issues. Horticultural oil is a smothering agent that is designed to suffocate any larvae, eggs, or live bugs hiding in your trees. Because of our temperate weather, bugs can become a big problem quickly if not managed properly. Not letting them get a head start in spring is your first line of defense against any wee beasties that might want to feast on your tree.
Applying them is simple. Get yourself two one-gallon tank sprayers. Add the concentrated oil to one and your concentrated fungicide in the other and mix with the appropriate amount of water (read the directions for ratio). Label each clearly and begin your treatments as soon as the trees drop their leaves. Pump up your sprayer and apply liberally. You should see the fluid running down the tree so don’t hold back. Ideally, you would start this on the day you prune your trees. I recommend applying on this schedule….
Week 1 – Horticultural oil
Week 2 – Copper Fungicide
Week 3 – Horticultural oil
Week 4 – Copper Fungicide
Week 5 – Horticultural oil
Week 6 – Copper Fungicide
You will want to make sure you have at least three days of no rain so check the weather before you apply. It is best to apply first thing in the morning so that the oils have a chance to dry on the tree and will not be washed off by nighttime or early morning dew.
Mulch and Compost
This is a great time to add compost and mulch under your trees. Proper nutrients and water are the last key to keeping your trees healthy. Although the trees are dormant and need very little water this time of year, adding compost at this point gives time for the compost to start breaking down and allows the natural bacteria and fungus in the soil to proliferate, thus creating more nutrients for your trees come spring. You can use manure in place of compost, if you prefer.
If you follow these few steps each winter, you will be rewarded with a healthy tree that will provide you with loads of fruit each summer for years to come. If you are looking for more information on fruit tree care or have any other garden related questions please let us know. Happy pruning!!!